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Breadcrumbs go here --> <li><a href="qdeclarativeelements.html">QML Elements</a></li> <li>QML Connections Element</li> </ul> </div> <div class="toolbuttons toolblock"> <ul> <li id="smallA" class="t_button">A</li> <li id="medA" class="t_button active">A</li> <li id="bigA" class="t_button">A</li> <li id="print" class="t_button"><a href="javascript:this.print();"> <span>Print</span></a></li> </ul> </div> </div> <div class="content mainContent"> <div class="toc"> <h3><a name="toc">Contents</a></h3> <ul> <li class="level1"><a href="#properties">Properties</a></li> <li class="level1"><a href="#details">Detailed Description</a></li> </ul> </div> <h1 class="title">QML Connections Element</h1> <span class="subtitle"></span> <!-- $$$Connections-brief --> <p>A Connections element describes generalized connections to signals. <a href="#details">More...</a></p> <!-- @@@Connections --> <p>This element was introduced in Qt 4.7.</p> <ul> <li><a href="qml-connections-members.html">List of all members, including inherited members</a></li> </ul> <a name="properties"></a> <h2>Properties</h2> <ul> <li class="fn"><b><b><a href="qml-connections.html#ignoreUnknownSignals-prop">ignoreUnknownSignals</a></b></b> : bool</li> <li class="fn"><b><b><a href="qml-connections.html#target-prop">target</a></b></b> : Object</li> </ul> <!-- $$$Connections-description --> <a name="details"></a> <h2>Detailed Description</h2> <p>A Connections object creates a connection to a QML signal.</p> <p>When connecting to signals in QML, the usual way is to create an "on<Signal>" handler that reacts when a signal is received, like this:</p> <pre class="qml"> <span class="type"><a href="qml-mousearea.html">MouseArea</a></span> { <span class="name">onClicked</span>: { <span class="name">foo</span>(<span class="name">parameters</span>) } }</pre> <p>However, it is not possible to connect to a signal in this way in some cases, such as when:</p> <ul> <li>Multiple connections to the same signal are required</li> <li>Creating connections outside the scope of the signal sender</li> <li>Connecting to targets not defined in QML</li> </ul> <p>When any of these are needed, the Connections element can be used instead.</p> <p>For example, the above code can be changed to use a Connections object, like this:</p> <pre class="qml"> <span class="type"><a href="qml-mousearea.html">MouseArea</a></span> { <span class="type">Connections</span> { <span class="name">onClicked</span>: <span class="name">foo</span>(<span class="name">parameters</span>) } }</pre> <p>More generally, the Connections object can be a child of some object other than the sender of the signal:</p> <pre class="qml"> <span class="type"><a href="qml-mousearea.html">MouseArea</a></span> { <span class="name">id</span>: <span class="name">area</span> } <span class="comment">// ...</span></pre> <pre class="qml"> <span class="type">Connections</span> { <span class="name">target</span>: <span class="name">area</span> <span class="name">onClicked</span>: <span class="name">foo</span>(<span class="name">parameters</span>) }</pre> <p><b>See also </b><a href="qtdeclarative.html">QtDeclarative</a>.</p> <!-- @@@Connections --> <h2>Property Documentation</h2> <!-- $$$ignoreUnknownSignals --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlPropNode"><p><a name="ignoreUnknownSignals-prop"></a><span class="name">ignoreUnknownSignals</span> : <span class="type"><a href="qml-bool.html">bool</a></span></p></td></tr></table></div><div class="qmldoc"><p>Normally, a connection to a non-existent signal produces runtime errors.</p> <p>If this property is set to <tt>true</tt>, such errors are ignored. This is useful if you intend to connect to different types of objects, handling a different set of signals for each object.</p> </div></div><!-- @@@ignoreUnknownSignals --> <br/> <!-- $$$target --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlPropNode"><p><a name="target-prop"></a><span class="name">target</span> : <span class="type">Object</span></p></td></tr></table></div><div class="qmldoc"><p>This property holds the object that sends the signal.</p> <p>If this property is not set, the <tt>target</tt> defaults to the parent of the Connection.</p> <p>If set to null, no connection is made and any signal handlers are ignored until the target is not null.</p> </div></div><!-- @@@target --> <br/> </div> </div> </div> <div class="ft"> <span></span> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2015 The Qt Company Ltd. 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