Correct JSON and Model with TreeStore and TreePanel

问题

I have a JSON String comes from the server side:

{"success":"true","total":"6","list":
  [{"id":"1","name":"folder1","parentid":"null","type":"0"},
   {"id":"2","name":"r1","parentid":"1","type":"1"},
   {"id":"3","name":"folder2","parentid":"1","type":"0"},
   {"id":"4","name":"r2","parentid":"3","type":"1"},
   {"id":"5","name":"r3","parentid":"null","type":"1"},
   {"id":"6","name":"folder3","parentid":"null","type":"0"}]}

How do I turn that into a tree? Can anyone suggest me how to get the elements in the list (id, name, parentid, type)?

回答1:

I used the following structure:

Model

Ext.define('MyApp.model.MyTreeModel', {
    extend: 'Ext.data.Model',
    fields: [
         'someStringIdentifier',
         'children',
         'dataForThisNode',
    ],
});

Store

Ext.define('MyApp.store.MyTreeStore', {
    extend: 'Ext.data.TreeStore',
    model: 'MyApp.model.MyTreeModel',
    storeId: 'cubeDynamicStoreId',
    autoLoad: false,

    proxy: {
        type: 'ajax',
        api: {
            read : '/myapp/rest/myquery',
        },
        reader: {
            type: 'json',
            root: 'children',
            successProperty: 'success',
            idProperty: 'id',
        },
    },

    // bug in extjs4.1 autoLoad is ignored
    // specifying "loaded: true" resolves the problem
    root: {
        expanded: true,
        loaded: true,
    },
});

Sample JSON ( use http://jsonviewer.stack.hu/ to visualize)

Use the leaf property to stop expansion at any node

{"children":{"leaf":false,"someStringIdentifier":"Total","dataForThisNode":{},"children":[{"leaf":true,"someStringIdentifier":"data1","dataForThisNode":{},"children":[{"leaf":false,"someStringIdentifier":"2012","dataForThisNode":{},"children":null},{"leaf":false,"someStringIdentifier":"2013","dataForThisNode":{},"children":null},{"leaf":false,"someStringIdentifier":"2014","dataForThisNode":{},"children":null},{"leaf":false,"someStringIdentifier":"2015","dataForThisNode":{},"children":null},{"leaf":false,"someStringIdentifier":"2016","dataForThisNode":{},"children":null},{"leaf":false,"someStringIdentifier":"2017","dataForThisNode":{},"children":null},{"leaf":false,"someStringIdentifier":"2018","dataForThisNode":{},"children":null}]},{"leaf":true,"someStringIdentifier":"data2","dataForThisNode":{},"children":[{"leaf":false,"someStringIdentifier":"2012","dataForThisNode":{},"children":null},{"leaf":false,"someStringIdentifier":"2013","dataForThisNode":{},"children":null},{"leaf":false,"someStringIdentifier":"2014","dataForThisNode":{},"children":null},{"leaf":false,"someStringIdentifier":"2015","dataForThisNode":{},"children":null},{"leaf":false,"someStringIdentifier":"2016","dataForThisNode":{},"children":null},{"leaf":false,"someStringIdentifier":"2017","dataForThisNode":{},"children":null},{"leaf":false,"someStringIdentifier":"2018","dataForThisNode":{},"children":null}]}]},"success":true}

回答2:

Let's start with the store definition:

Ext.define('app.store.Tasks', {

    extend: 'Ext.data.TreeStore',    
    model:  'app.model.Task',

    autoSync: true,
    autoLoad: true,

    root: {
        text: 'Root',
        id: 'NULL',
        expanded: true
    },
});

The important thing to note is that we are extending TreeStore here. Thus, our model records will be wrapped with Ext.data.NodeInterface, which included many tree-related fields (like, for example, parentNode).

Then to the model definition:

Ext.define('app.model.Task', {
    extend: 'Ext.data.Model',
    fields: [
        {name: 'name'     , type: 'string'},

        {name: 'iconCls'  , type: 'string', defaultValue: 'treenode-no-icon'},
        {name: 'expanded' , type: 'boolean', defaultValue: true, persist: false},
        {name: 'index'     , type: 'int'},        
    ],

    proxy: {
        type: 'direct',

        api: {
            create:  Tasks.Create,
            read:    Tasks.Read,
            update:  Tasks.Update,
            destroy: Tasks.Destroy,
        },
    },

});

The only 'real' field we've defined is name, All the others are part of NodeInterface: iconCls has a default value of no icon; expanded is set with persist:false so collapsing/expanding a node won't result in an update server call; index is included so if the user re-order nodes (using drag and drop) server calls will be made.

Notice that there's no id field since a a model's default idProperty is id, ExtJS is smart enough to figure that if your JSON has id field in it - it represents the unique id of the record.

Also note there's no parentId field - by providing correct JSON (with nodes having children property), NodeInterface work out the correct parentNode of each node.

Then the JSON:

{
    "success":true,
    "children":[
     {
        "id":"1",
        "name":"Home",
        "children":[
           {
              "id":"6",
              "name":"Emails",
              "leaf":true
           },
           {
              "id":"7",
              "name":"Bath",
              "leaf":true
           }
        ],
        "leaf":false
     },         
    ]
}

That's pretty much it!

回答3:

The first answer on this subject from Izhaki is great, but it seems misleading and will not work as is if your expectation is to see the description for nodes. I spent several hours struggling with this. The only way to see this description is to rename "name" with "text". see below.

Ext.define('app.model.Task', {
extend: 'Ext.data.Model',
fields: [
    {name: 'text'     , type: 'string'},

    {name: 'iconCls'  , type: 'string', defaultValue: 'treenode-no-icon'},
    {name: 'expanded' , type: 'boolean', defaultValue: true, persist: false},
    {name: 'index'     , type: 'int'},        
],

来源：https://stackoverflow.com/questions/11763648/correct-json-and-model-with-treestore-and-treepanel