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Breadcrumbs go here --> <li><a href="qdeclarativeelements.html">QML Elements</a></li> <li>QML XmlRole 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 XmlRole Element</h1> <span class="subtitle"></span> <!-- $$$XmlRole-brief --> <p>The XmlRole element allows you to specify a role for an <a href="qml-xmllistmodel.html">XmlListModel</a>. <a href="#details">More...</a></p> <!-- @@@XmlRole --> <p>This element was introduced in Qt 4.7.</p> <ul> <li><a href="qml-xmlrole-members.html">List of all members, including inherited members</a></li> </ul> <a name="properties"></a> <h2>Properties</h2> <ul> <li class="fn"><b><b><a href="qml-xmlrole.html#isKey-prop">isKey</a></b></b> : bool</li> <li class="fn"><b><b><a href="qml-xmlrole.html#name-prop">name</a></b></b> : string</li> <li class="fn"><b><b><a href="qml-xmlrole.html#query-prop">query</a></b></b> : string</li> </ul> <!-- $$$XmlRole-description --> <a name="details"></a> <h2>Detailed Description</h2> <p><b>See also </b><a href="qtdeclarative.html">QtDeclarative</a>.</p> <!-- @@@XmlRole --> <h2>Property Documentation</h2> <!-- $$$isKey --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlPropNode"><p><a name="isKey-prop"></a><span class="name">isKey</span> : <span class="type"><a href="qml-bool.html">bool</a></span></p></td></tr></table></div><div class="qmldoc"><p>Defines whether this is a key role.</p> <p>Key roles are used to to determine whether a set of values should be updated or added to the XML list model when <a href="qml-xmllistmodel.html#reload-method">XmlListModel::reload()</a> is called.</p> <p><b>See also </b><a href="qml-xmllistmodel.html">XmlListModel</a>.</p> </div></div><!-- @@@isKey --> <br/> <!-- $$$name --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlPropNode"><p><a name="name-prop"></a><span class="name">name</span> : <span class="type"><a href="qml-string.html">string</a></span></p></td></tr></table></div><div class="qmldoc"><p>The name for the role. This name is used to access the model data for this role.</p> <p>For example, the following model has a role named "title", which can be accessed from the view's delegate:</p> <pre class="qml"> <span class="type"><a href="qml-xmllistmodel.html">XmlListModel</a></span> { <span class="name">id</span>: <span class="name">xmlModel</span> <span class="comment">// ...</span> <span class="type"><a href="qml-xmlrole.html">XmlRole</a></span> { <span class="name">name</span>: <span class="string">"title"</span> <span class="name">query</span>: <span class="string">"title/string()"</span> } }</pre> <pre class="qml"> <span class="type"><a href="qml-listview.html">ListView</a></span> { <span class="name">model</span>: <span class="name">xmlModel</span> <span class="name">delegate</span>: <span class="name">Text</span> { <span class="name">text</span>: <span class="name">title</span> } }</pre> </div></div><!-- @@@name --> <br/> <!-- $$$query --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlPropNode"><p><a name="query-prop"></a><span class="name">query</span> : <span class="type"><a href="qml-string.html">string</a></span></p></td></tr></table></div><div class="qmldoc"><p>The relative XPath expression query for this role. The query must be relative; it cannot start with a '/'.</p> <p>For example, if there is an XML document like this:</p> <pre class="cpp"> <?xml version="1.0" encoding="iso-8859-1" ?> <catalogue> <book type="Hardcover"> <title>C++ GUI Programming with Qt 4</title> <year>2006</year> <author>Jasmin Blanchette</author> <author>Mark Summerfield</author> </book> <book type="Paperback"> <title>Programming with Qt</title> <year>2002</year> <author>Matthias Kalle Dalheimer</author> </book> </catalogue></pre> <p>Here are some valid XPath expressions for <a href="qml-xmlrole.html">XmlRole</a> queries on this document:</p> <pre class="qml"> <span class="type"><a href="qml-xmllistmodel.html">XmlListModel</a></span> { <span class="name">id</span>: <span class="name">model</span> ... <span class="comment">// XmlRole queries will be made on <book> elements</span> <span class="name">query</span>: <span class="string">"/catalogue/book"</span> <span class="comment">// query the book title</span> <span class="type"><a href="qml-xmlrole.html">XmlRole</a></span> { <span class="name">name</span>: <span class="string">"title"</span>; <span class="name">query</span>: <span class="string">"title/string()"</span> } <span class="comment">// query the book's year</span> <span class="type"><a href="qml-xmlrole.html">XmlRole</a></span> { <span class="name">name</span>: <span class="string">"year"</span>; <span class="name">query</span>: <span class="string">"year/number()"</span> } <span class="comment">// query the book's type (the '@' indicates 'type' is an attribute, not an element)</span> <span class="type"><a href="qml-xmlrole.html">XmlRole</a></span> { <span class="name">name</span>: <span class="string">"type"</span>; <span class="name">query</span>: <span class="string">"@type/string()"</span> } <span class="comment">// query the book's first listed author (note in XPath the first index is 1, not 0)</span> <span class="type"><a href="qml-xmlrole.html">XmlRole</a></span> { <span class="name">name</span>: <span class="string">"first_author"</span>; <span class="name">query</span>: <span class="string">"author[1]/string()"</span> } }</pre> <p>See the <a href="http://www.w3.org/TR/xpath20/">W3C XPath 2.0 specification</a> for more information.</p> </div></div><!-- @@@query --> <br/> </div> </div> </div> <div class="ft"> <span></span> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2013 Digia Plc and/or its subsidiaries. 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