Difference between revisions of "JSONListModel"

From Qt Wiki
Jump to: navigation, search
 
Line 1: Line 1:
JSONListModel is a pure-<span class="caps">QML</span> component that allows using <span class="caps">JSON</span> data as datasource for a <span class="caps">QML</span> ListView.
+
JSONListModel is a pure-QML component that allows using JSON data as datasource for a QML ListView.
  
==Code==
+
== Code ==
  
The JSONListModel code is Open Source and available under the <span class="caps">MIT</span> license at:
+
The JSONListModel code is Open Source and available under the MIT license at:
  
[https://github.com/kromain/qml-utils github.com/kromain/qml-utils] ''[github.com]''
+
&quot;github.com/kromain/qml-utils&amp;quot;:https://github.com/kromain/qml-utils
  
==Features==
+
== Features ==
  
* mimics the XMLListModel component by providing similar <span class="caps">API</span> and properties
+
* mimics the XMLListModel component by providing similar API and properties
* supports both source-based and string-based <span class="caps">JSON</span> data
+
* supports both source-based and string-based JSON data
* support complex <span class="caps">JSON</span> documents and queries via <span class="caps">JSONP</span>ath (XPath for <span class="caps">JSON</span>)
+
* support complex JSON documents and queries via JSONPath (XPath for JSON)
  
==Example==
+
== Example ==
  
With a file '''jsonData.txt''' containing:<br />
+
With a file '''jsonData.txt''' containing:<br /><code><br />{ &quot;store&amp;quot;: {<br /> &quot;book&amp;quot;: [<br /> { &quot;category&amp;quot;: &quot;reference&amp;quot;,<br /> &quot;author&amp;quot;: &quot;Nigel Rees&amp;quot;,<br /> &quot;title&amp;quot;: &quot;Sayings of the Century&amp;quot;,<br /> &quot;price&amp;quot;: 8.95<br /> },<br /> { &quot;category&amp;quot;: &quot;fiction&amp;quot;,<br /> &quot;author&amp;quot;: &quot;Evelyn Waugh&amp;quot;,<br /> &quot;title&amp;quot;: &quot;Sword of Honour&amp;quot;,<br /> &quot;price&amp;quot;: 12.99<br /> },<br /> { &quot;category&amp;quot;: &quot;fiction&amp;quot;,<br /> &quot;author&amp;quot;: &quot;Herman Melville&amp;quot;,<br /> &quot;title&amp;quot;: &quot;Moby Dick&amp;quot;,<br /> &quot;isbn&amp;quot;: &quot;0-553-21311-3&amp;quot;,<br /> &quot;price&amp;quot;: 8.99<br /> },<br /> { &quot;category&amp;quot;: &quot;fiction&amp;quot;,<br /> &quot;author&amp;quot;: &quot;J. R. R. Tolkien&amp;quot;,<br /> &quot;title&amp;quot;: &quot;The Lord of the Rings&amp;quot;,<br /> &quot;isbn&amp;quot;: &quot;0-395-19395-8&amp;quot;,<br /> &quot;price&amp;quot;: 22.99<br /> }<br /> ],<br /> &quot;bicycle&amp;quot;: {<br /> &quot;color&amp;quot;: &quot;red&amp;quot;,<br /> &quot;price&amp;quot;: 19.95<br /> }<br /> }<br />}<br /></code>
  
 
We can write:
 
We can write:
 +
 +
<code><br /> JSONListModel {<br /> id: jsonModel1<br /> source: &quot;jsonData.txt&amp;quot;<br /> // All books in the store object<br /> query: &quot;$.store.book[*]&quot;<br /> }
 +
 +
JSONListModel {<br /> id: jsonModel2<br /> source: &quot;jsonData.txt&amp;quot;<br /> // Books less than $10<br /> query: &quot;$..book[?(</code>.price&amp;lt;10)]&quot;<br /> }
 +
 +
JSONListModel {<br /> id: jsonModel3<br /> json: '[  {&quot;label&amp;quot;: &quot;Answer&amp;quot;, &quot;value&amp;quot;: &quot;42&amp;quot;},  {&quot;label&amp;quot;: &quot;Pastis&amp;quot;, &quot;value&amp;quot;: &quot;51&amp;quot;},  {&quot;label&amp;quot;: &quot;Alsace&amp;quot;, &quot;value&amp;quot;: &quot;67&amp;quot;},  {&quot;label&amp;quot;: &quot;Alsace&amp;quot;, &quot;value&amp;quot;: &quot;68&amp;quot;}  ]'<br /> // Labels starting with 'A'<br /> query: &quot;$[?(<code>.label.charAt(0)==='A')]&quot;<br /> }<br /></code>
  
 
And use it in views and delegates like this:
 
And use it in views and delegates like this:
  
===Categories:===
+
<code><br /> ListView {<br /> model: jsonModel1.model
 +
 
 +
delegate: Component {<br /> Text {<br /> // Can be any of the JSON properties: model.author, model.price, etc.<br /> text: model.title<br /> }<br /> }<br /></code>
  
* [[:Category:Developing with Qt|Developing_with_Qt]]
+
[[Category:snippets]]<br />[[Category:Developing_with_Qt::Qt Quick]]<br />[[Category:JSON]]
** [[:Category:Developing with Qt::Qt-Quick|Qt Quick]]
 
* [[:Category:JSON|JSON]]
 
* [[:Category:snippets|snippets]]
 

Revision as of 14:32, 23 February 2015

JSONListModel is a pure-QML component that allows using JSON data as datasource for a QML ListView.

Code

The JSONListModel code is Open Source and available under the MIT license at:

"github.com/kromain/qml-utils&quot;:https://github.com/kromain/qml-utils

Features

  • mimics the XMLListModel component by providing similar API and properties
  • supports both source-based and string-based JSON data
  • support complex JSON documents and queries via JSONPath (XPath for JSON)

Example

With a file jsonData.txt containing:

{ "store&quot;: {
"book&quot;: [
{ "category&quot;: "reference&quot;,
"author&quot;: "Nigel Rees&quot;,
"title&quot;: "Sayings of the Century&quot;,
"price&quot;: 8.95
},
{ "category&quot;: "fiction&quot;,
"author&quot;: "Evelyn Waugh&quot;,
"title&quot;: "Sword of Honour&quot;,
"price&quot;: 12.99
},
{ "category&quot;: "fiction&quot;,
"author&quot;: "Herman Melville&quot;,
"title&quot;: "Moby Dick&quot;,
"isbn&quot;: "0-553-21311-3&quot;,
"price&quot;: 8.99
},
{ "category&quot;: "fiction&quot;,
"author&quot;: "J. R. R. Tolkien&quot;,
"title&quot;: "The Lord of the Rings&quot;,
"isbn&quot;: "0-395-19395-8&quot;,
"price&quot;: 22.99
}
],
"bicycle&quot;: {
"color&quot;: "red&quot;,
"price&quot;: 19.95
}
}
}

We can write:


JSONListModel {
id: jsonModel1
source: "jsonData.txt&quot;
// All books in the store object
query: "$.store.book[*]"
}

JSONListModel {
id: jsonModel2
source: "jsonData.txt&quot;
// Books less than $10
query: "$..book[?(
.price&lt;10)]"
}

JSONListModel {
id: jsonModel3
json: '[ {"label&quot;: "Answer&quot;, "value&quot;: "42&quot;}, {"label&quot;: "Pastis&quot;, "value&quot;: "51&quot;}, {"label&quot;: "Alsace&quot;, "value&quot;: "67&quot;}, {"label&quot;: "Alsace&quot;, "value&quot;: "68&quot;} ]'
// Labels starting with 'A'
query: "$[?(.label.charAt(0)==='A')]"
}

And use it in views and delegates like this:


ListView {
model: jsonModel1.model

delegate: Component {
Text {
// Can be any of the JSON properties: model.author, model.price, etc.
text: model.title
}
}