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  16         <h1>eVaf Tutorial</h1>
  17
  18         <h2>07 - Storage Module</h2>
  19
  20         <p>Create the <tt>module.cpp</tt> file in the <tt>src/apps/PswGen/Storage</tt> directory:</tt>
  21
  22         <pre class="hl"><span class="hl com">/**</span>
  23 <span class="hl com"> * &#64;file PswGen/Storage/module.cpp</span>
  24 <span class="hl com"> */</span>
  25
  26 <span class="hl ppc">#include</span> <span class="hl pps">&quot;module.h&quot;</span><span class="hl ppc"></span>
  27 <span class="hl ppc">#include &lt;QtCore&gt;</span></pre>
  28
  29         <p>Copy version information files from the <tt>Generator<tt> module:</p>
  30
  31         <pre>evaf/src/apps/PswGen/Storage $ <code>cp ../Generator/version.{h,rc} .</code></pre>
  32
  33         <p>Modify the <tt>version.h</tt> file:</p>
  34
  35         <pre class="hl"><span class="hl com">/**</span>
  36 <span class="hl com"> * &#64;file PswGen/Storage/version.h</span>
  37 <span class="hl com"> */</span>
  38
  39 <span class="hl ppc">#ifndef __PSWGEN_STORAGE_VERSION_H</span>
  40 <span class="hl ppc">#define   __PSWGEN_STORAGE_VERSION_H</span>
  41
  42 <span class="hl ppc">#include &lt;version_rc.h&gt;</span>
  43
  44 <span class="hl com">/**</span>
  45 <span class="hl com"> * Module/library version number in the form major,minor,release,build</span>
  46 <span class="hl com"> */</span>
  47 <span class="hl ppc">#define VER_FILE_VERSION                0,1,1,1</span>
  48
  49 <span class="hl com">/**</span>
  50 <span class="hl com"> * Module/library version number in the string format (shall end with \0)</span>
  51 <span class="hl com"> */</span>
  52 <span class="hl ppc">#define VER_FILE_VERSION_STR</span>            <span class="hl pps">&quot;0.1.1.1\0&quot;</span><span class="hl ppc"></span>
  53
  54 <span class="hl com">/**</span>
  55 <span class="hl com"> * Module/library name (shall end with \0)</span>
  56 <span class="hl com"> */</span>
  57 <span class="hl ppc">#define VER_MODULE_NAME_STR</span>             <span class="hl pps">&quot;PswStorage\0&quot;</span><span class="hl ppc"></span>
  58
  59 <span class="hl com">/**</span>
  60 <span class="hl com"> * Module type (see version_rc.h for all the types)</span>
  61 <span class="hl com"> */</span>
  62 <span class="hl ppc">#define VER_MODULE_TYPE                 MT_GENERIC</span>
  63
  64 <span class="hl com">/**</span>
  65 <span class="hl com"> * Module type in the string format (see version_rc for all the types)</span>
  66 <span class="hl com"> */</span>
  67 <span class="hl ppc">#define VER_MODULE_TYPE_STR             MT_GENERIC</span>
  68
  69 <span class="hl com">/**</span>
  70 <span class="hl com"> * Original file name for windows (shall end with \0)</span>
  71 <span class="hl com"> */</span>
  72 <span class="hl ppc">#define VER_ORIGINAL_FILE_NAME_STR</span>      <span class="hl pps">&quot;PswStorage.dll\0&quot;</span><span class="hl ppc"></span>
  73
  74 <span class="hl com">/**</span>
  75 <span class="hl com"> * Description of the module/library (shall end with \0)</span>
  76 <span class="hl com"> */</span>
  77 <span class="hl ppc">#define VER_FILE_DESCRIPTION_STR</span>         <span class="hl pps">&quot;Module that stores data for generating strong passwords.\0&quot;</span><span class="hl ppc"></span>
  78
  79 <span class="hl ppc">#endif</span> <span class="hl slc">// version.h</span><span class="hl ppc"></span></pre>
  80
  81         <p>Include the <tt>version.h</tt> header file in <tt>module.cpp</tt> and export version information:</p>
  82
  83         <pre class="hl">
  84 <span class="hl ppc">#include</span> <span class="hl pps">&quot;version.h&quot;</span><span class="hl ppc"></span>
  85
  86 <span class="hl kwd">VER_EXPORT_VERSION_INFO</span><span class="hl opt">()</span></pre>
  87
  88         <p>Make it a proper Qt plugin by using the <tt>Q_EXPORT_PLUGIN2()</tt> macro:</p>
  89
  90         <pre class="hl"><span class="hl kwd">Q_EXPORT_PLUGIN2</span><span class="hl opt">(</span>VER_MODULE_NAME_STR<span class="hl opt">,</span> eVaf<span class="hl opt">::</span>PswGen<span class="hl opt">::</span>Storage<span class="hl opt">::</span>Module<span class="hl opt">)</span></pre>
  91
  92         <p>The <tt>Module</tt> class creates the internal <tt>StorageImpl</tt> object in the constructor, but initializes it in the
  93         <tt>init()</tt> method. This way we can return errors from the module if initialization fails. Similarly, we finalize the
  94         internal <tt>StorageImpl</tt> object in the <tt>done()</tt> method and delete in the destructor.</p>
  95
  96         <p>The module is ready when the internal <tt>StorageImpl</tt> object is initalized and we set the <tt>mReady</tt> flag to
  97         <tt>true</tt> when the initialization is done and back to <tt>false</tt> in the <tt>done()</tt> method.</p>
  98
  99         <p>The rest of the code sets the name of the object and outputs info messages.</p>
 100
 101         <pre class="hl">Module<span class="hl opt">::</span><span class="hl kwd">Module</span><span class="hl opt">()</span>
 102     <span class="hl opt">:</span> Plugins<span class="hl opt">::</span><span class="hl kwd">iPlugin</span><span class="hl opt">()</span>
 103     <span class="hl opt">,</span> <span class="hl kwd">mReady</span><span class="hl opt">(</span><span class="hl kwa">false</span><span class="hl opt">)</span>
 104 <span class="hl opt">{</span>
 105     <span class="hl kwd">setObjectName</span><span class="hl opt">(</span><span class="hl kwd">QString</span><span class="hl opt">(</span><span class="hl str">&quot;%1.%2&quot;</span><span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>VER_MODULE_NAME_STR<span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>__FUNCTION__<span class="hl opt">));</span>
 106
 107     mStorage <span class="hl opt">=</span> <span class="hl kwa">new</span> Internal<span class="hl opt">::</span>StorageImpl<span class="hl opt">;</span>
 108
 109     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s created&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 110 <span class="hl opt">}</span>
 111
 112 Module<span class="hl opt">::~</span><span class="hl kwd">Module</span><span class="hl opt">()</span>
 113 <span class="hl opt">{</span>
 114     <span class="hl kwa">delete</span> mStorage<span class="hl opt">;</span>
 115
 116     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s destroyed&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 117 <span class="hl opt">}</span>
 118
 119 <span class="hl kwb">bool</span> Module<span class="hl opt">::</span><span class="hl kwd">init</span><span class="hl opt">(</span>QString <span class="hl kwb">const</span> <span class="hl opt">&amp;</span> args<span class="hl opt">)</span>
 120 <span class="hl opt">{</span>
 121     <span class="hl kwd">Q_UNUSED</span><span class="hl opt">(</span>args<span class="hl opt">);</span>
 122
 123     <span class="hl kwa">if</span> <span class="hl opt">(!</span>mStorage<span class="hl opt">-&gt;</span><span class="hl kwd">init</span><span class="hl opt">())</span>
 124         <span class="hl kwa">return false</span><span class="hl opt">;</span>
 125
 126     mReady <span class="hl opt">=</span> <span class="hl kwa">true</span><span class="hl opt">;</span>
 127
 128     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s initialized&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 129
 130     <span class="hl kwa">return true</span><span class="hl opt">;</span>
 131 <span class="hl opt">}</span>
 132
 133 <span class="hl kwb">void</span> Module<span class="hl opt">::</span><span class="hl kwd">done</span><span class="hl opt">()</span>
 134 <span class="hl opt">{</span>
 135     mReady <span class="hl opt">=</span> <span class="hl kwa">false</span><span class="hl opt">;</span>
 136
 137     mStorage<span class="hl opt">-&gt;</span><span class="hl kwd">done</span><span class="hl opt">();</span>
 138
 139     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s finalized&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 140 <span class="hl opt">}</span></pre>
 141
 142         <p>The <tt>StorageImpl</tt> class does very little in the constructor and in the destructor:</p>
 143
 144         <pre class="hl">StorageImpl<span class="hl opt">::</span><span class="hl kwd">StorageImpl</span><span class="hl opt">()</span>
 145     <span class="hl opt">:</span> <span class="hl kwd">QAbstractListModel</span><span class="hl opt">()</span>
 146 <span class="hl opt">{</span>
 147     <span class="hl kwd">setObjectName</span><span class="hl opt">(</span><span class="hl kwd">QString</span><span class="hl opt">(</span><span class="hl str">&quot;%1.iGenerator&quot;</span><span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>VER_MODULE_NAME_STR<span class="hl opt">));</span>
 148
 149     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s created&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 150 <span class="hl opt">}</span>
 151
 152 StorageImpl<span class="hl opt">::~</span><span class="hl kwd">StorageImpl</span><span class="hl opt">()</span>
 153 <span class="hl opt">{</span>
 154     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s destroyed&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 155 <span class="hl opt">}</span></pre>
 156
 157         <p>Initialization of the <tt>StorageImpl</tt> class happens in the <tt>init()</tt> method, where we open the database connection,
 158         create tables if necessary and load data from the database. We also register the <tt>iStorage</tt> interface in the global
 159         registry of interfaces.</p>
 160
 161         <p>We use the <tt>Common::iApp</tt> interface to find the data root directory where the SQLITE database file is going to be
 162         located.</p>
 163
 164         <pre class="hl"><span class="hl kwb">bool</span> StorageImpl<span class="hl opt">::</span><span class="hl kwd">init</span><span class="hl opt">()</span>
 165 <span class="hl opt">{</span>
 166     <span class="hl slc">// Open the database</span>
 167     <span class="hl kwa">if</span> <span class="hl opt">(!</span>QSqlDatabase<span class="hl opt">::</span><span class="hl kwd">contains</span><span class="hl opt">(</span>DbConnectionName<span class="hl opt">)) {</span>
 168         <span class="hl slc">// No database connection yet</span>
 169         mDb <span class="hl opt">=</span> QSqlDatabase<span class="hl opt">::</span><span class="hl kwd">addDatabase</span><span class="hl opt">(</span><span class="hl str">&quot;QSQLITE&quot;</span><span class="hl opt">,</span> DbConnectionName<span class="hl opt">);</span>
 170         mDb<span class="hl opt">.</span><span class="hl kwd">setDatabaseName</span><span class="hl opt">(</span>Common<span class="hl opt">::</span>iApp<span class="hl opt">::</span><span class="hl kwd">instance</span><span class="hl opt">()-&gt;</span><span class="hl kwd">dataRootDir</span><span class="hl opt">() +</span> DbName<span class="hl opt">);</span>
 171         <span class="hl kwa">if</span> <span class="hl opt">(!</span>mDb<span class="hl opt">.</span><span class="hl kwd">open</span><span class="hl opt">()) {</span>
 172             QSqlError err <span class="hl opt">=</span> mDb<span class="hl opt">.</span><span class="hl kwd">lastError</span><span class="hl opt">();</span>
 173             <span class="hl kwd">EVAF_ERROR</span><span class="hl opt">(</span><span class="hl str">&quot;Failed to open database : %s&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>err<span class="hl opt">.</span><span class="hl kwd">text</span><span class="hl opt">()));</span>
 174             <span class="hl kwa">return false</span><span class="hl opt">;</span>
 175         <span class="hl opt">}</span>
 176     <span class="hl opt">}</span>
 177     <span class="hl kwa">else</span> <span class="hl opt">{</span>
 178         <span class="hl slc">// Database connection already exists</span>
 179         mDb <span class="hl opt">=</span> QSqlDatabase<span class="hl opt">::</span><span class="hl kwd">database</span><span class="hl opt">(</span>DbConnectionName<span class="hl opt">);</span>
 180     <span class="hl opt">}</span>
 181
 182     <span class="hl slc">// Create tables if necessary</span>
 183     <span class="hl kwa">if</span> <span class="hl opt">(!</span><span class="hl kwd">createTables</span><span class="hl opt">())</span>
 184         <span class="hl kwa">return false</span><span class="hl opt">;</span>
 185
 186     <span class="hl slc">// Load data</span>
 187     <span class="hl kwa">if</span> <span class="hl opt">(!</span><span class="hl kwd">loadData</span><span class="hl opt">())</span>
 188         <span class="hl kwa">return false</span><span class="hl opt">;</span>
 189
 190     <span class="hl slc">/// Register our interface</span>
 191     Common<span class="hl opt">::</span>iRegistry<span class="hl opt">::</span><span class="hl kwd">instance</span><span class="hl opt">()-&gt;</span><span class="hl kwd">registerInterface</span><span class="hl opt">(</span><span class="hl str">&quot;iStorage&quot;</span><span class="hl opt">,</span> <span class="hl kwa">this</span><span class="hl opt">);</span>
 192
 193     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s initialized&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 194
 195     <span class="hl kwa">return true</span><span class="hl opt">;</span>
 196 <span class="hl opt">}</span></pre>
 197
 198         <p>The finalization of the <tt>StorageImpl</tt> class happens in the <tt>done()</tt> method, where we only need to clear the list
 199         of shared data objects:</p>
 200
 201         <pre class="hl"><span class="hl kwb">void</span> StorageImpl<span class="hl opt">::</span><span class="hl kwd">done</span><span class="hl opt">()</span>
 202 <span class="hl opt">{</span>
 203     mData<span class="hl opt">.</span><span class="hl kwd">clear</span><span class="hl opt">();</span>
 204     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s finalized&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 205 <span class="hl opt">}</span></pre>
 206
 207         <p>The <tt>StorageImpl::save()</tt> method verifies that the shared data object is valid and the name not empty. Then it either
 208         adds a new data record to the database or updates an existing one.</p>
 209
 210         <pre class="hl"><span class="hl kwb">bool</span> StorageImpl<span class="hl opt">::</span><span class="hl kwd">save</span><span class="hl opt">(</span>QString <span class="hl kwb">const</span> <span class="hl opt">&amp;</span> name<span class="hl opt">,</span> QExplicitlySharedDataPointer<span class="hl opt">&lt;</span>Storage<span class="hl opt">::</span>Data<span class="hl opt">&gt;</span> data<span class="hl opt">)</span>
 211 <span class="hl opt">{</span>
 212     <span class="hl kwd">EVAF_TEST_X</span><span class="hl opt">(</span>data<span class="hl opt">,</span> <span class="hl str">&quot;Data cannot be null&quot;</span><span class="hl opt">);</span>
 213     <span class="hl kwd">EVAF_TEST_X</span><span class="hl opt">(!</span>name<span class="hl opt">.</span><span class="hl kwd">isEmpty</span><span class="hl opt">(),</span> <span class="hl str">&quot;Name cannot be empty&quot;</span><span class="hl opt">);</span>
 214
 215     <span class="hl slc">// Is it an update or a new data record?</span>
 216     <span class="hl kwa">if</span> <span class="hl opt">(</span>mData<span class="hl opt">.</span><span class="hl kwd">constFind</span><span class="hl opt">(</span>name<span class="hl opt">) !=</span> mData<span class="hl opt">.</span><span class="hl kwd">constEnd</span><span class="hl opt">()) {</span>
 217         <span class="hl slc">// This is an update</span>
 218         <span class="hl kwa">if</span> <span class="hl opt">(</span>data<span class="hl opt">-&gt;</span><span class="hl kwd">modified</span><span class="hl opt">()) {</span>
 219             QSqlQuery <span class="hl kwd">q</span><span class="hl opt">(</span>mDb<span class="hl opt">);</span>
 220             <span class="hl kwa">if</span> <span class="hl opt">(!</span>q<span class="hl opt">.</span><span class="hl kwd">exec</span><span class="hl opt">(</span><span class="hl kwd">QString</span><span class="hl opt">(</span><span class="hl str">&quot;UPDATE data SET length =</span> <span class="hl esc">\'</span><span class="hl str">%1</span><span class="hl esc">\'</span><span class="hl str">, flags =</span> <span class="hl esc">\'</span><span class="hl str">%2</span><span class="hl esc">\'</span> <span class="hl str">WHERE name =</span> <span class="hl esc">\'</span><span class="hl str">%3</span><span class="hl esc">\'</span><span class="hl str">;&quot;</span><span class="hl opt">)</span>
 221                             <span class="hl opt">.</span><span class="hl kwd">arg</span><span class="hl opt">(</span>data<span class="hl opt">-&gt;</span><span class="hl kwd">length</span><span class="hl opt">()).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>data<span class="hl opt">-&gt;</span><span class="hl kwd">flags</span><span class="hl opt">()).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>name<span class="hl opt">))) {</span>
 222                 QSqlError err <span class="hl opt">=</span> mDb<span class="hl opt">.</span><span class="hl kwd">lastError</span><span class="hl opt">();</span>
 223                 <span class="hl kwd">EVAF_ERROR</span><span class="hl opt">(</span><span class="hl str">&quot;Failed to update</span> <span class="hl esc">\'</span><span class="hl str">%s</span><span class="hl esc">\'</span> <span class="hl str">: %s&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>name<span class="hl opt">),</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>err<span class="hl opt">.</span><span class="hl kwd">text</span><span class="hl opt">()));</span>
 224                 <span class="hl kwa">return false</span><span class="hl opt">;</span>
 225             <span class="hl opt">}</span>
 226         <span class="hl opt">}</span>
 227     <span class="hl opt">}</span>
 228     <span class="hl kwa">else</span> <span class="hl opt">{</span>
 229         <span class="hl slc">// Store to the database</span>
 230         QSqlQuery <span class="hl kwd">q</span><span class="hl opt">(</span>mDb<span class="hl opt">);</span>
 231         <span class="hl kwa">if</span> <span class="hl opt">(!</span>q<span class="hl opt">.</span><span class="hl kwd">exec</span><span class="hl opt">(</span><span class="hl kwd">QString</span><span class="hl opt">(</span><span class="hl str">&quot;INSERT INTO data (name, length, flags) VALUES (</span><span class="hl esc">\'</span><span class="hl str">%1</span><span class="hl esc">\'</span><span class="hl str">, %2, %3);&quot;</span><span class="hl opt">)</span>
 232                             <span class="hl opt">.</span><span class="hl kwd">arg</span><span class="hl opt">(</span>name<span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>data<span class="hl opt">-&gt;</span><span class="hl kwd">length</span><span class="hl opt">())</span>
 233                             <span class="hl opt">.</span><span class="hl kwd">arg</span><span class="hl opt">(</span><span class="hl kwb">int</span><span class="hl opt">(</span>data<span class="hl opt">-&gt;</span><span class="hl kwd">flags</span><span class="hl opt">())))) {</span>
 234             QSqlError err <span class="hl opt">=</span> mDb<span class="hl opt">.</span><span class="hl kwd">lastError</span><span class="hl opt">();</span>
 235             <span class="hl kwd">EVAF_ERROR</span><span class="hl opt">(</span><span class="hl str">&quot;Failed to insert</span> <span class="hl esc">\'</span><span class="hl str">%s</span><span class="hl esc">\'</span> <span class="hl str">: %s&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>name<span class="hl opt">),</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>err<span class="hl opt">.</span><span class="hl kwd">text</span><span class="hl opt">()));</span>
 236             <span class="hl kwa">return false</span><span class="hl opt">;</span>
 237         <span class="hl opt">}</span>
 238
 239         <span class="hl slc">// Store also into the local hash</span>
 240         mData<span class="hl opt">.</span><span class="hl kwd">insert</span><span class="hl opt">(</span>name<span class="hl opt">,</span> data<span class="hl opt">);</span>
 241
 242         <span class="hl slc">// Reset the model</span>
 243         <span class="hl kwd">reset</span><span class="hl opt">();</span>
 244     <span class="hl opt">}</span>
 245
 246     data<span class="hl opt">-&gt;</span><span class="hl kwd">reset</span><span class="hl opt">();</span>
 247
 248     <span class="hl kwa">return true</span><span class="hl opt">;</span>
 249 <span class="hl opt">}</span></pre>
 250
 251         <p>Calling the <tt>reset()</tt> method resets the <tt>QAbstractItemModel</tt> data model and assures that the associated widget
 252         updates the <tt>QCompleter</tt> with a fresh list of auto completion words. Resetting the data model in this case is fine as
 253         long as the data model is simple and the list short. The proper way would be finding out the actual insertion point and using
 254         <tt>beginInsertRows()</tt> and <tt>endInsertRows()</tt> methods.</p>
 255
 256         <p>Querying data is much simpler thanks to the internal <tt>QMap</tt> container:</p>
 257
 258         <pre class="hl">QExplicitlySharedDataPointer<span class="hl opt">&lt;</span>Storage<span class="hl opt">::</span>Data<span class="hl opt">&gt;</span> StorageImpl<span class="hl opt">::</span><span class="hl kwd">query</span><span class="hl opt">(</span>QString <span class="hl kwb">const</span> <span class="hl opt">&amp;</span> name<span class="hl opt">)</span> <span class="hl kwb">const</span>
 259 <span class="hl opt">{</span>
 260     QMap<span class="hl opt">&lt;</span>QString<span class="hl opt">,</span> QExplicitlySharedDataPointer<span class="hl opt">&lt;</span>Storage<span class="hl opt">::</span>Data<span class="hl opt">&gt; &gt;::</span>const_iterator it <span class="hl opt">=</span> mData<span class="hl opt">.</span><span class="hl kwd">constFind</span><span class="hl opt">(</span>name<span class="hl opt">);</span>
 261     <span class="hl kwa">if</span> <span class="hl opt">(</span>it <span class="hl opt">!=</span> mData<span class="hl opt">.</span><span class="hl kwd">constEnd</span><span class="hl opt">())</span>
 262         <span class="hl kwa">return</span> it<span class="hl opt">.</span><span class="hl kwd">value</span><span class="hl opt">();</span>
 263     <span class="hl kwa">else</span>
 264         <span class="hl kwa">return</span> QExplicitlySharedDataPointer<span class="hl opt">&lt;</span>Storage<span class="hl opt">::</span>Data<span class="hl opt">&gt;();</span>
 265 <span class="hl opt">}</span></pre>
 266
 267         <p>We return an empty <tt>QExplicitlySharedDataPointer</tt> object if no data objects with the given name exists.</p>
 268
 269         <p>The <tt>data()</tt> method returns names of data objects for the <tt>QCompleter</tt> auto completion list of words:</p>
 270
 271         <pre class="hl">QVariant StorageImpl<span class="hl opt">::</span><span class="hl kwd">data</span><span class="hl opt">(</span>QModelIndex <span class="hl kwb">const</span> <span class="hl opt">&amp;</span> index<span class="hl opt">,</span> <span class="hl kwb">int</span> role<span class="hl opt">)</span> <span class="hl kwb">const</span>
 272 <span class="hl opt">{</span>
 273     <span class="hl kwa">if</span> <span class="hl opt">(!</span>index<span class="hl opt">.</span><span class="hl kwd">isValid</span><span class="hl opt">() ||</span> index<span class="hl opt">.</span><span class="hl kwd">row</span><span class="hl opt">() &lt;</span> <span class="hl num">0</span> <span class="hl opt">||</span> index<span class="hl opt">.</span><span class="hl kwd">row</span><span class="hl opt">() &gt;=</span> mData<span class="hl opt">.</span><span class="hl kwd">size</span><span class="hl opt">() ||</span> index<span class="hl opt">.</span><span class="hl kwd">column</span><span class="hl opt">() !=</span> <span class="hl num">0</span><span class="hl opt">)</span>
 274         <span class="hl kwa">return</span> <span class="hl kwd">QVariant</span><span class="hl opt">();</span>
 275
 276     <span class="hl kwa">if</span> <span class="hl opt">(</span>role <span class="hl opt">==</span> Qt<span class="hl opt">::</span>EditRole <span class="hl opt">||</span> role <span class="hl opt">==</span> Qt<span class="hl opt">::</span>DisplayRole<span class="hl opt">)</span>
 277         <span class="hl kwa">return</span> mData<span class="hl opt">.</span><span class="hl kwd">keys</span><span class="hl opt">().</span><span class="hl kwd">at</span><span class="hl opt">(</span>index<span class="hl opt">.</span><span class="hl kwd">row</span><span class="hl opt">());</span>
 278
 279     <span class="hl kwa">return</span> <span class="hl kwd">QVariant</span><span class="hl opt">();</span>
 280 <span class="hl opt">}</span></pre>
 281
 282         <p>The <tt>createTabled()</tt> method creates the <tt>data</tt> table if it does not exist. This function could be improved to
 283         alter the <tt>data</tt> table if it exists, but is from an older version. Right now we assume that if the table exists, it
 284         is good for our application:</p>
 285
 286         <pre class="hl"><span class="hl kwb">bool</span> StorageImpl<span class="hl opt">::</span><span class="hl kwd">createTables</span><span class="hl opt">()</span>
 287 <span class="hl opt">{</span>
 288     QSqlQuery <span class="hl kwd">q</span><span class="hl opt">(</span>mDb<span class="hl opt">);</span>
 289     <span class="hl kwa">if</span> <span class="hl opt">(!</span>q<span class="hl opt">.</span><span class="hl kwd">exec</span><span class="hl opt">(</span><span class="hl str">&quot;SELECT name FROM sqlite_master WHERE type=</span><span class="hl esc">\'</span><span class="hl str">table</span><span class="hl esc">\'</span> <span class="hl str">AND name=</span><span class="hl esc">\'</span><span class="hl str">data</span><span class="hl esc">\'</span><span class="hl str">;&quot;</span><span class="hl opt">)) {</span>
 290         QSqlError err <span class="hl opt">=</span> mDb<span class="hl opt">.</span><span class="hl kwd">lastError</span><span class="hl opt">();</span>
 291         <span class="hl kwd">EVAF_ERROR</span><span class="hl opt">(</span><span class="hl str">&quot;Failed to query database : %s&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>err<span class="hl opt">.</span><span class="hl kwd">text</span><span class="hl opt">()));</span>
 292         <span class="hl kwa">return false</span><span class="hl opt">;</span>
 293     <span class="hl opt">}</span>
 294
 295     <span class="hl kwa">if</span> <span class="hl opt">(</span>q<span class="hl opt">.</span><span class="hl kwd">isActive</span><span class="hl opt">() &amp;&amp;</span> q<span class="hl opt">.</span><span class="hl kwd">isSelect</span><span class="hl opt">() &amp;&amp;</span> q<span class="hl opt">.</span><span class="hl kwd">first</span><span class="hl opt">())</span>
 296         <span class="hl kwa">return true</span><span class="hl opt">;</span> <span class="hl slc">// We already have a table called 'data'</span>
 297
 298     <span class="hl slc">// Create the 'data' table</span>
 299     <span class="hl kwa">if</span> <span class="hl opt">(!</span>q<span class="hl opt">.</span><span class="hl kwd">exec</span><span class="hl opt">(</span><span class="hl str">&quot;CREATE TABLE data (name text primary key not null, length integer, flags integer);&quot;</span><span class="hl opt">)) {</span>
 300         QSqlError err <span class="hl opt">=</span> mDb<span class="hl opt">.</span><span class="hl kwd">lastError</span><span class="hl opt">();</span>
 301         <span class="hl kwd">EVAF_ERROR</span><span class="hl opt">(</span><span class="hl str">&quot;Failed to create table</span> <span class="hl esc">\'</span><span class="hl str">data</span><span class="hl esc">\'</span> <span class="hl str">: %s&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>err<span class="hl opt">.</span><span class="hl kwd">text</span><span class="hl opt">()));</span>
 302         <span class="hl kwa">return false</span><span class="hl opt">;</span>
 303     <span class="hl opt">}</span>
 304
 305     <span class="hl kwa">return true</span><span class="hl opt">;</span>
 306 <span class="hl opt">}</span></pre>
 307
 308         <p>Finally, the <tt>loadData()</tt> method loads all the data records from the database to the memory:</p>
 309
 310         <pre class="hl"><span class="hl kwb">bool</span> StorageImpl<span class="hl opt">::</span><span class="hl kwd">loadData</span><span class="hl opt">()</span>
 311 <span class="hl opt">{</span>
 312     QSqlQuery <span class="hl kwd">q</span><span class="hl opt">(</span>mDb<span class="hl opt">);</span>
 313     <span class="hl kwa">if</span> <span class="hl opt">(!</span>q<span class="hl opt">.</span><span class="hl kwd">exec</span><span class="hl opt">(</span><span class="hl str">&quot;SELECT name, length, flags FROM data;&quot;</span><span class="hl opt">)) {</span>
 314         QSqlError err <span class="hl opt">=</span> mDb<span class="hl opt">.</span><span class="hl kwd">lastError</span><span class="hl opt">();</span>
 315         <span class="hl kwd">EVAF_ERROR</span><span class="hl opt">(</span><span class="hl str">&quot;Failed to query database : %s&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>err<span class="hl opt">.</span><span class="hl kwd">text</span><span class="hl opt">()));</span>
 316         <span class="hl kwa">return false</span><span class="hl opt">;</span>
 317     <span class="hl opt">}</span>
 318
 319     <span class="hl kwa">while</span> <span class="hl opt">(</span>q<span class="hl opt">.</span><span class="hl kwd">next</span><span class="hl opt">()) {</span>
 320         QString name <span class="hl opt">=</span> q<span class="hl opt">.</span><span class="hl kwd">value</span><span class="hl opt">(</span><span class="hl num">0</span><span class="hl opt">).</span><span class="hl kwd">toString</span><span class="hl opt">();</span>
 321         QExplicitlySharedDataPointer<span class="hl opt">&lt;</span>Storage<span class="hl opt">::</span>Data<span class="hl opt">&gt;</span> <span class="hl kwd">data</span><span class="hl opt">(</span><span class="hl kwa">new</span> Storage<span class="hl opt">::</span><span class="hl kwd">Data</span><span class="hl opt">(</span>name<span class="hl opt">,</span> q<span class="hl opt">.</span><span class="hl kwd">value</span><span class="hl opt">(</span><span class="hl num">1</span><span class="hl opt">).</span><span class="hl kwd">toInt</span><span class="hl opt">(),</span> <span class="hl kwd">uint</span><span class="hl opt">(</span>q<span class="hl opt">.</span><span class="hl kwd">value</span><span class="hl opt">(</span><span class="hl num">2</span><span class="hl opt">).</span><span class="hl kwd">toInt</span><span class="hl opt">())));</span>
 322         mData<span class="hl opt">.</span><span class="hl kwd">insert</span><span class="hl opt">(</span>name<span class="hl opt">,</span> data<span class="hl opt">);</span>
 323     <span class="hl opt">}</span>
 324
 325     <span class="hl kwd">reset</span><span class="hl opt">();</span>
 326
 327     <span class="hl kwa">return true</span><span class="hl opt">;</span>
 328 <span class="hl opt">}</span></pre>
 329
 330         <p>Resetting the <tt>QAbstractItemModel</tt> data model here is ok, becase before loading any data the model is supposed to be
 331         empty.</p>
 332
 333         <p>Here is the complete <tt>module.cpp</tt> file:
 334
 335         <pre class="hl"><span class="hl com">/**</span>
 336 <span class="hl com"> * &#64;file PswGen/Storage/module.cpp</span>
 337 <span class="hl com"> */</span>
 338
 339 <span class="hl ppc">#include</span> <span class="hl pps">&quot;module.h&quot;</span><span class="hl ppc"></span>
 340 <span class="hl ppc">#include</span> <span class="hl pps">&quot;version.h&quot;</span><span class="hl ppc"></span>
 341
 342 <span class="hl ppc">#include &lt;Common/Globals&gt;</span>
 343 <span class="hl ppc">#include &lt;Common/iLogger&gt;</span>
 344 <span class="hl ppc">#include &lt;Common/iRegistry&gt;</span>
 345 <span class="hl ppc">#include &lt;Common/iApp&gt;</span>
 346
 347 <span class="hl ppc">#include &lt;QtCore&gt;</span>
 348 <span class="hl ppc">#include &lt;QtSql/QtSql&gt;</span>
 349
 350 <span class="hl kwd">VER_EXPORT_VERSION_INFO</span><span class="hl opt">()</span>
 351 <span class="hl kwd">Q_EXPORT_PLUGIN2</span><span class="hl opt">(</span>VER_MODULE_NAME_STR<span class="hl opt">,</span> eVaf<span class="hl opt">::</span>PswGen<span class="hl opt">::</span>Storage<span class="hl opt">::</span>Module<span class="hl opt">)</span>
 352
 353 <span class="hl kwa">using namespace</span> eVaf<span class="hl opt">;</span>
 354 <span class="hl kwa">using namespace</span> eVaf<span class="hl opt">::</span>PswGen<span class="hl opt">;</span>
 355 <span class="hl kwa">using namespace</span> eVaf<span class="hl opt">::</span>PswGen<span class="hl opt">::</span>Storage<span class="hl opt">;</span>
 356
 357 Module<span class="hl opt">::</span><span class="hl kwd">Module</span><span class="hl opt">()</span>
 358     <span class="hl opt">:</span> Plugins<span class="hl opt">::</span><span class="hl kwd">iPlugin</span><span class="hl opt">()</span>
 359     <span class="hl opt">,</span> <span class="hl kwd">mReady</span><span class="hl opt">(</span><span class="hl kwa">false</span><span class="hl opt">)</span>
 360 <span class="hl opt">{</span>
 361     <span class="hl kwd">setObjectName</span><span class="hl opt">(</span><span class="hl kwd">QString</span><span class="hl opt">(</span><span class="hl str">&quot;%1.%2&quot;</span><span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>VER_MODULE_NAME_STR<span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>__FUNCTION__<span class="hl opt">));</span>
 362
 363     mStorage <span class="hl opt">=</span> <span class="hl kwa">new</span> Internal<span class="hl opt">::</span>StorageImpl<span class="hl opt">;</span>
 364
 365     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s created&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 366 <span class="hl opt">}</span>
 367
 368 Module<span class="hl opt">::~</span><span class="hl kwd">Module</span><span class="hl opt">()</span>
 369 <span class="hl opt">{</span>
 370     <span class="hl kwa">delete</span> mStorage<span class="hl opt">;</span>
 371
 372     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s destroyed&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 373 <span class="hl opt">}</span>
 374
 375 <span class="hl kwb">bool</span> Module<span class="hl opt">::</span><span class="hl kwd">init</span><span class="hl opt">(</span>QString <span class="hl kwb">const</span> <span class="hl opt">&amp;</span> args<span class="hl opt">)</span>
 376 <span class="hl opt">{</span>
 377     <span class="hl kwd">Q_UNUSED</span><span class="hl opt">(</span>args<span class="hl opt">);</span>
 378
 379     <span class="hl kwa">if</span> <span class="hl opt">(!</span>mStorage<span class="hl opt">-&gt;</span><span class="hl kwd">init</span><span class="hl opt">())</span>
 380         <span class="hl kwa">return false</span><span class="hl opt">;</span>
 381
 382     mReady <span class="hl opt">=</span> <span class="hl kwa">true</span><span class="hl opt">;</span>
 383
 384     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s initialized&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 385
 386     <span class="hl kwa">return true</span><span class="hl opt">;</span>
 387 <span class="hl opt">}</span>
 388
 389 <span class="hl kwb">void</span> Module<span class="hl opt">::</span><span class="hl kwd">done</span><span class="hl opt">()</span>
 390 <span class="hl opt">{</span>
 391     mReady <span class="hl opt">=</span> <span class="hl kwa">false</span><span class="hl opt">;</span>
 392
 393     mStorage<span class="hl opt">-&gt;</span><span class="hl kwd">done</span><span class="hl opt">();</span>
 394
 395     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s finalized&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 396 <span class="hl opt">}</span>
 397
 398 <span class="hl kwa">using namespace</span> eVaf<span class="hl opt">::</span>PswGen<span class="hl opt">::</span>Storage<span class="hl opt">::</span>Internal<span class="hl opt">;</span>
 399
 400 <span class="hl kwb">char const</span> <span class="hl opt">*</span> <span class="hl kwb">const</span> StorageImpl<span class="hl opt">::</span>DbConnectionName <span class="hl opt">=</span> <span class="hl str">&quot;PswGenDB&quot;</span><span class="hl opt">;</span>
 401
 402 <span class="hl kwb">char const</span> <span class="hl opt">*</span> <span class="hl kwb">const</span> StorageImpl<span class="hl opt">::</span>DbName <span class="hl opt">=</span> <span class="hl str">&quot;PswGen.sqlite&quot;</span><span class="hl opt">;</span>
 403
 404 StorageImpl<span class="hl opt">::</span><span class="hl kwd">StorageImpl</span><span class="hl opt">()</span>
 405     <span class="hl opt">:</span> <span class="hl kwd">QAbstractListModel</span><span class="hl opt">()</span>
 406 <span class="hl opt">{</span>
 407     <span class="hl kwd">setObjectName</span><span class="hl opt">(</span><span class="hl kwd">QString</span><span class="hl opt">(</span><span class="hl str">&quot;%1.iGenerator&quot;</span><span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>VER_MODULE_NAME_STR<span class="hl opt">));</span>
 408
 409     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s created&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 410 <span class="hl opt">}</span>
 411
 412 StorageImpl<span class="hl opt">::~</span><span class="hl kwd">StorageImpl</span><span class="hl opt">()</span>
 413 <span class="hl opt">{</span>
 414     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s destroyed&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 415 <span class="hl opt">}</span>
 416
 417 <span class="hl kwb">bool</span> StorageImpl<span class="hl opt">::</span><span class="hl kwd">init</span><span class="hl opt">()</span>
 418 <span class="hl opt">{</span>
 419     <span class="hl slc">// Open the database</span>
 420     <span class="hl kwa">if</span> <span class="hl opt">(!</span>QSqlDatabase<span class="hl opt">::</span><span class="hl kwd">contains</span><span class="hl opt">(</span>DbConnectionName<span class="hl opt">)) {</span>
 421         <span class="hl slc">// No database connection yet</span>
 422         mDb <span class="hl opt">=</span> QSqlDatabase<span class="hl opt">::</span><span class="hl kwd">addDatabase</span><span class="hl opt">(</span><span class="hl str">&quot;QSQLITE&quot;</span><span class="hl opt">,</span> DbConnectionName<span class="hl opt">);</span>
 423         mDb<span class="hl opt">.</span><span class="hl kwd">setDatabaseName</span><span class="hl opt">(</span>Common<span class="hl opt">::</span>iApp<span class="hl opt">::</span><span class="hl kwd">instance</span><span class="hl opt">()-&gt;</span><span class="hl kwd">dataRootDir</span><span class="hl opt">() +</span> DbName<span class="hl opt">);</span>
 424         <span class="hl kwa">if</span> <span class="hl opt">(!</span>mDb<span class="hl opt">.</span><span class="hl kwd">open</span><span class="hl opt">()) {</span>
 425             QSqlError err <span class="hl opt">=</span> mDb<span class="hl opt">.</span><span class="hl kwd">lastError</span><span class="hl opt">();</span>
 426             <span class="hl kwd">EVAF_ERROR</span><span class="hl opt">(</span><span class="hl str">&quot;Failed to open database : %s&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>err<span class="hl opt">.</span><span class="hl kwd">text</span><span class="hl opt">()));</span>
 427             <span class="hl kwa">return false</span><span class="hl opt">;</span>
 428         <span class="hl opt">}</span>
 429     <span class="hl opt">}</span>
 430     <span class="hl kwa">else</span> <span class="hl opt">{</span>
 431         <span class="hl slc">// Database connection already exists</span>
 432         mDb <span class="hl opt">=</span> QSqlDatabase<span class="hl opt">::</span><span class="hl kwd">database</span><span class="hl opt">(</span>DbConnectionName<span class="hl opt">);</span>
 433     <span class="hl opt">}</span>
 434
 435     <span class="hl slc">// Create tables if necessary</span>
 436     <span class="hl kwa">if</span> <span class="hl opt">(!</span><span class="hl kwd">createTables</span><span class="hl opt">())</span>
 437         <span class="hl kwa">return false</span><span class="hl opt">;</span>
 438
 439     <span class="hl slc">// Load data</span>
 440     <span class="hl kwa">if</span> <span class="hl opt">(!</span><span class="hl kwd">loadData</span><span class="hl opt">())</span>
 441         <span class="hl kwa">return false</span><span class="hl opt">;</span>
 442
 443     <span class="hl slc">/// Register our interface</span>
 444     Common<span class="hl opt">::</span>iRegistry<span class="hl opt">::</span><span class="hl kwd">instance</span><span class="hl opt">()-&gt;</span><span class="hl kwd">registerInterface</span><span class="hl opt">(</span><span class="hl str">&quot;iStorage&quot;</span><span class="hl opt">,</span> <span class="hl kwa">this</span><span class="hl opt">);</span>
 445
 446     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s initialized&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 447
 448     <span class="hl kwa">return true</span><span class="hl opt">;</span>
 449 <span class="hl opt">}</span>
 450
 451 <span class="hl kwb">void</span> StorageImpl<span class="hl opt">::</span><span class="hl kwd">done</span><span class="hl opt">()</span>
 452 <span class="hl opt">{</span>
 453     mData<span class="hl opt">.</span><span class="hl kwd">clear</span><span class="hl opt">();</span>
 454     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s finalized&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 455 <span class="hl opt">}</span>
 456
 457 <span class="hl kwb">bool</span> StorageImpl<span class="hl opt">::</span><span class="hl kwd">save</span><span class="hl opt">(</span>QString <span class="hl kwb">const</span> <span class="hl opt">&amp;</span> name<span class="hl opt">,</span> QExplicitlySharedDataPointer<span class="hl opt">&lt;</span>Storage<span class="hl opt">::</span>Data<span class="hl opt">&gt;</span> data<span class="hl opt">)</span>
 458 <span class="hl opt">{</span>
 459     <span class="hl kwd">EVAF_TEST_X</span><span class="hl opt">(</span>data<span class="hl opt">,</span> <span class="hl str">&quot;Data cannot be null&quot;</span><span class="hl opt">);</span>
 460     <span class="hl kwd">EVAF_TEST_X</span><span class="hl opt">(!</span>name<span class="hl opt">.</span><span class="hl kwd">isEmpty</span><span class="hl opt">(),</span> <span class="hl str">&quot;Name cannot be empty&quot;</span><span class="hl opt">);</span>
 461
 462     <span class="hl slc">// Is it an update or a new data record?</span>
 463     <span class="hl kwa">if</span> <span class="hl opt">(</span>mData<span class="hl opt">.</span><span class="hl kwd">constFind</span><span class="hl opt">(</span>name<span class="hl opt">) !=</span> mData<span class="hl opt">.</span><span class="hl kwd">constEnd</span><span class="hl opt">()) {</span>
 464         <span class="hl slc">// This is an update</span>
 465         <span class="hl kwa">if</span> <span class="hl opt">(</span>data<span class="hl opt">-&gt;</span><span class="hl kwd">modified</span><span class="hl opt">()) {</span>
 466             QSqlQuery <span class="hl kwd">q</span><span class="hl opt">(</span>mDb<span class="hl opt">);</span>
 467             <span class="hl kwa">if</span> <span class="hl opt">(!</span>q<span class="hl opt">.</span><span class="hl kwd">exec</span><span class="hl opt">(</span><span class="hl kwd">QString</span><span class="hl opt">(</span><span class="hl str">&quot;UPDATE data SET length =</span> <span class="hl esc">\'</span><span class="hl str">%1</span><span class="hl esc">\'</span><span class="hl str">, flags =</span> <span class="hl esc">\'</span><span class="hl str">%2</span><span class="hl esc">\'</span> <span class="hl str">WHERE name =</span> <span class="hl esc">\'</span><span class="hl str">%3</span><span class="hl esc">\'</span><span class="hl str">;&quot;</span><span class="hl opt">)</span>
 468                             <span class="hl opt">.</span><span class="hl kwd">arg</span><span class="hl opt">(</span>data<span class="hl opt">-&gt;</span><span class="hl kwd">length</span><span class="hl opt">()).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>data<span class="hl opt">-&gt;</span><span class="hl kwd">flags</span><span class="hl opt">()).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>name<span class="hl opt">))) {</span>
 469                 QSqlError err <span class="hl opt">=</span> mDb<span class="hl opt">.</span><span class="hl kwd">lastError</span><span class="hl opt">();</span>
 470                 <span class="hl kwd">EVAF_ERROR</span><span class="hl opt">(</span><span class="hl str">&quot;Failed to update</span> <span class="hl esc">\'</span><span class="hl str">%s</span><span class="hl esc">\'</span> <span class="hl str">: %s&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>name<span class="hl opt">),</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>err<span class="hl opt">.</span><span class="hl kwd">text</span><span class="hl opt">()));</span>
 471                 <span class="hl kwa">return false</span><span class="hl opt">;</span>
 472             <span class="hl opt">}</span>
 473         <span class="hl opt">}</span>
 474     <span class="hl opt">}</span>
 475     <span class="hl kwa">else</span> <span class="hl opt">{</span>
 476         <span class="hl slc">// Store to the database</span>
 477         QSqlQuery <span class="hl kwd">q</span><span class="hl opt">(</span>mDb<span class="hl opt">);</span>
 478         <span class="hl kwa">if</span> <span class="hl opt">(!</span>q<span class="hl opt">.</span><span class="hl kwd">exec</span><span class="hl opt">(</span><span class="hl kwd">QString</span><span class="hl opt">(</span><span class="hl str">&quot;INSERT INTO data (name, length, flags) VALUES (</span><span class="hl esc">\'</span><span class="hl str">%1</span><span class="hl esc">\'</span><span class="hl str">, %2, %3);&quot;</span><span class="hl opt">)</span>
 479                             <span class="hl opt">.</span><span class="hl kwd">arg</span><span class="hl opt">(</span>name<span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>data<span class="hl opt">-&gt;</span><span class="hl kwd">length</span><span class="hl opt">())</span>
 480                             <span class="hl opt">.</span><span class="hl kwd">arg</span><span class="hl opt">(</span><span class="hl kwb">int</span><span class="hl opt">(</span>data<span class="hl opt">-&gt;</span><span class="hl kwd">flags</span><span class="hl opt">())))) {</span>
 481             QSqlError err <span class="hl opt">=</span> mDb<span class="hl opt">.</span><span class="hl kwd">lastError</span><span class="hl opt">();</span>
 482             <span class="hl kwd">EVAF_ERROR</span><span class="hl opt">(</span><span class="hl str">&quot;Failed to insert</span> <span class="hl esc">\'</span><span class="hl str">%s</span><span class="hl esc">\'</span> <span class="hl str">: %s&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>name<span class="hl opt">),</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>err<span class="hl opt">.</span><span class="hl kwd">text</span><span class="hl opt">()));</span>
 483             <span class="hl kwa">return false</span><span class="hl opt">;</span>
 484         <span class="hl opt">}</span>
 485
 486         <span class="hl slc">// Store also into the local hash</span>
 487         mData<span class="hl opt">.</span><span class="hl kwd">insert</span><span class="hl opt">(</span>name<span class="hl opt">,</span> data<span class="hl opt">);</span>
 488
 489         <span class="hl slc">// Reset the model</span>
 490         <span class="hl kwd">reset</span><span class="hl opt">();</span>
 491     <span class="hl opt">}</span>
 492
 493     data<span class="hl opt">-&gt;</span><span class="hl kwd">reset</span><span class="hl opt">();</span>
 494
 495     <span class="hl kwa">return true</span><span class="hl opt">;</span>
 496 <span class="hl opt">}</span>
 497
 498 QExplicitlySharedDataPointer<span class="hl opt">&lt;</span>Storage<span class="hl opt">::</span>Data<span class="hl opt">&gt;</span> StorageImpl<span class="hl opt">::</span><span class="hl kwd">query</span><span class="hl opt">(</span>QString <span class="hl kwb">const</span> <span class="hl opt">&amp;</span> name<span class="hl opt">)</span> <span class="hl kwb">const</span>
 499 <span class="hl opt">{</span>
 500     QMap<span class="hl opt">&lt;</span>QString<span class="hl opt">,</span> QExplicitlySharedDataPointer<span class="hl opt">&lt;</span>Storage<span class="hl opt">::</span>Data<span class="hl opt">&gt; &gt;::</span>const_iterator it <span class="hl opt">=</span> mData<span class="hl opt">.</span><span class="hl kwd">constFind</span><span class="hl opt">(</span>name<span class="hl opt">);</span>
 501     <span class="hl kwa">if</span> <span class="hl opt">(</span>it <span class="hl opt">!=</span> mData<span class="hl opt">.</span><span class="hl kwd">constEnd</span><span class="hl opt">())</span>
 502         <span class="hl kwa">return</span> it<span class="hl opt">.</span><span class="hl kwd">value</span><span class="hl opt">();</span>
 503     <span class="hl kwa">else</span>
 504         <span class="hl kwa">return</span> QExplicitlySharedDataPointer<span class="hl opt">&lt;</span>Storage<span class="hl opt">::</span>Data<span class="hl opt">&gt;();</span>
 505 <span class="hl opt">}</span>
 506
 507 QVariant StorageImpl<span class="hl opt">::</span><span class="hl kwd">data</span><span class="hl opt">(</span>QModelIndex <span class="hl kwb">const</span> <span class="hl opt">&amp;</span> index<span class="hl opt">,</span> <span class="hl kwb">int</span> role<span class="hl opt">)</span> <span class="hl kwb">const</span>
 508 <span class="hl opt">{</span>
 509     <span class="hl kwa">if</span> <span class="hl opt">(!</span>index<span class="hl opt">.</span><span class="hl kwd">isValid</span><span class="hl opt">() ||</span> index<span class="hl opt">.</span><span class="hl kwd">row</span><span class="hl opt">() &lt;</span> <span class="hl num">0</span> <span class="hl opt">||</span> index<span class="hl opt">.</span><span class="hl kwd">row</span><span class="hl opt">() &gt;=</span> mData<span class="hl opt">.</span><span class="hl kwd">size</span><span class="hl opt">() ||</span> index<span class="hl opt">.</span><span class="hl kwd">column</span><span class="hl opt">() !=</span> <span class="hl num">0</span><span class="hl opt">)</span>
 510         <span class="hl kwa">return</span> <span class="hl kwd">QVariant</span><span class="hl opt">();</span>
 511
 512     <span class="hl kwa">if</span> <span class="hl opt">(</span>role <span class="hl opt">==</span> Qt<span class="hl opt">::</span>EditRole <span class="hl opt">||</span> role <span class="hl opt">==</span> Qt<span class="hl opt">::</span>DisplayRole<span class="hl opt">)</span>
 513         <span class="hl kwa">return</span> mData<span class="hl opt">.</span><span class="hl kwd">keys</span><span class="hl opt">().</span><span class="hl kwd">at</span><span class="hl opt">(</span>index<span class="hl opt">.</span><span class="hl kwd">row</span><span class="hl opt">());</span>
 514
 515     <span class="hl kwa">return</span> <span class="hl kwd">QVariant</span><span class="hl opt">();</span>
 516 <span class="hl opt">}</span>
 517
 518 <span class="hl kwb">bool</span> StorageImpl<span class="hl opt">::</span><span class="hl kwd">createTables</span><span class="hl opt">()</span>
 519 <span class="hl opt">{</span>
 520     QSqlQuery <span class="hl kwd">q</span><span class="hl opt">(</span>mDb<span class="hl opt">);</span>
 521     <span class="hl kwa">if</span> <span class="hl opt">(!</span>q<span class="hl opt">.</span><span class="hl kwd">exec</span><span class="hl opt">(</span><span class="hl str">&quot;SELECT name FROM sqlite_master WHERE type=</span><span class="hl esc">\'</span><span class="hl str">table</span><span class="hl esc">\'</span> <span class="hl str">AND name=</span><span class="hl esc">\'</span><span class="hl str">data</span><span class="hl esc">\'</span><span class="hl str">;&quot;</span><span class="hl opt">)) {</span>
 522         QSqlError err <span class="hl opt">=</span> mDb<span class="hl opt">.</span><span class="hl kwd">lastError</span><span class="hl opt">();</span>
 523         <span class="hl kwd">EVAF_ERROR</span><span class="hl opt">(</span><span class="hl str">&quot;Failed to query database : %s&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>err<span class="hl opt">.</span><span class="hl kwd">text</span><span class="hl opt">()));</span>
 524         <span class="hl kwa">return false</span><span class="hl opt">;</span>
 525     <span class="hl opt">}</span>
 526
 527     <span class="hl kwa">if</span> <span class="hl opt">(</span>q<span class="hl opt">.</span><span class="hl kwd">isActive</span><span class="hl opt">() &amp;&amp;</span> q<span class="hl opt">.</span><span class="hl kwd">isSelect</span><span class="hl opt">() &amp;&amp;</span> q<span class="hl opt">.</span><span class="hl kwd">first</span><span class="hl opt">())</span>
 528         <span class="hl kwa">return true</span><span class="hl opt">;</span> <span class="hl slc">// We already have a table called 'data'</span>
 529
 530     <span class="hl slc">// Create the 'data' table</span>
 531     <span class="hl kwa">if</span> <span class="hl opt">(!</span>q<span class="hl opt">.</span><span class="hl kwd">exec</span><span class="hl opt">(</span><span class="hl str">&quot;CREATE TABLE data (name text primary key not null, length integer, flags integer);&quot;</span><span class="hl opt">)) {</span>
 532         QSqlError err <span class="hl opt">=</span> mDb<span class="hl opt">.</span><span class="hl kwd">lastError</span><span class="hl opt">();</span>
 533         <span class="hl kwd">EVAF_ERROR</span><span class="hl opt">(</span><span class="hl str">&quot;Failed to create table</span> <span class="hl esc">\'</span><span class="hl str">data</span><span class="hl esc">\'</span> <span class="hl str">: %s&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>err<span class="hl opt">.</span><span class="hl kwd">text</span><span class="hl opt">()));</span>
 534         <span class="hl kwa">return false</span><span class="hl opt">;</span>
 535     <span class="hl opt">}</span>
 536
 537     <span class="hl kwa">return true</span><span class="hl opt">;</span>
 538 <span class="hl opt">}</span>
 539
 540 <span class="hl kwb">bool</span> StorageImpl<span class="hl opt">::</span><span class="hl kwd">loadData</span><span class="hl opt">()</span>
 541 <span class="hl opt">{</span>
 542     QSqlQuery <span class="hl kwd">q</span><span class="hl opt">(</span>mDb<span class="hl opt">);</span>
 543     <span class="hl kwa">if</span> <span class="hl opt">(!</span>q<span class="hl opt">.</span><span class="hl kwd">exec</span><span class="hl opt">(</span><span class="hl str">&quot;SELECT name, length, flags FROM data;&quot;</span><span class="hl opt">)) {</span>
 544         QSqlError err <span class="hl opt">=</span> mDb<span class="hl opt">.</span><span class="hl kwd">lastError</span><span class="hl opt">();</span>
 545         <span class="hl kwd">EVAF_ERROR</span><span class="hl opt">(</span><span class="hl str">&quot;Failed to query database : %s&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span>err<span class="hl opt">.</span><span class="hl kwd">text</span><span class="hl opt">()));</span>
 546         <span class="hl kwa">return false</span><span class="hl opt">;</span>
 547     <span class="hl opt">}</span>
 548
 549     <span class="hl kwa">while</span> <span class="hl opt">(</span>q<span class="hl opt">.</span><span class="hl kwd">next</span><span class="hl opt">()) {</span>
 550         QString name <span class="hl opt">=</span> q<span class="hl opt">.</span><span class="hl kwd">value</span><span class="hl opt">(</span><span class="hl num">0</span><span class="hl opt">).</span><span class="hl kwd">toString</span><span class="hl opt">();</span>
 551         QExplicitlySharedDataPointer<span class="hl opt">&lt;</span>Storage<span class="hl opt">::</span>Data<span class="hl opt">&gt;</span> <span class="hl kwd">data</span><span class="hl opt">(</span><span class="hl kwa">new</span> Storage<span class="hl opt">::</span><span class="hl kwd">Data</span><span class="hl opt">(</span>name<span class="hl opt">,</span> q<span class="hl opt">.</span><span class="hl kwd">value</span><span class="hl opt">(</span><span class="hl num">1</span><span class="hl opt">).</span><span class="hl kwd">toInt</span><span class="hl opt">(),</span> <span class="hl kwd">uint</span><span class="hl opt">(</span>q<span class="hl opt">.</span><span class="hl kwd">value</span><span class="hl opt">(</span><span class="hl num">2</span><span class="hl opt">).</span><span class="hl kwd">toInt</span><span class="hl opt">())));</span>
 552         mData<span class="hl opt">.</span><span class="hl kwd">insert</span><span class="hl opt">(</span>name<span class="hl opt">,</span> data<span class="hl opt">);</span>
 553     <span class="hl opt">}</span>
 554
 555     <span class="hl kwd">reset</span><span class="hl opt">();</span>
 556
 557     <span class="hl kwa">return true</span><span class="hl opt">;</span>
 558 <span class="hl opt">}</span></pre>
 559
 560         <p>Next -- <a href="pswgen08.html">Building Storage Module</a>.</p>
 561
 562     </body>
 563 </html>