X-Git-Url: http://git.ithinksw.org/extjs.git/blobdiff_plain/0494b8d9b9bb03ab6c22b34dae81261e3cd7e3e6..7a654f8d43fdb43d78b63d90528bed6e86b608cc:/docs/api/Ext.data.reader.Json.html?ds=sidebyside diff --git a/docs/api/Ext.data.reader.Json.html b/docs/api/Ext.data.reader.Json.html new file mode 100644 index 00000000..0b108d3d --- /dev/null +++ b/docs/api/Ext.data.reader.Json.html @@ -0,0 +1,261 @@ +Ext.data.reader.Json | Ext JS 4.0 Documentation +
For up to date documentation and features, visit +http://docs.sencha.com/ext-js/4-0

Sencha Documentation

+ + + + + +

Hierarchy

Ext.data.reader.Reader
Ext.data.reader.Json

The JSON Reader is used by a Proxy to read a server response that is sent back in JSON format. This usually +happens as a result of loading a Store - for example we might create something like this:

+ + + + +
Ext.define('User', {
+    extend: 'Ext.data.Model',
+    fields: ['id', 'name', 'email']
+});
+
+var store = new Ext.data.Store({
+    model: 'User',
+    proxy: {
+        type: 'ajax',
+        url : 'users.json',
+        reader: {
+            type: 'json'
+        }
+    }
+});
+
+ + + + +

The example above creates a 'User' model. Models are explained in the Model docs if you're +not already familiar with them.

+ + + + +

We created the simplest type of JSON Reader possible by simply telling our Store's +Proxy that we want a JSON Reader. The Store automatically passes the configured model to the +Store, so it is as if we passed this instead: + +

reader: {
+    type : 'json',
+    model: 'User'
+}
+
+ +

The reader we set up is ready to read data from our server - at the moment it will accept a response like this:

+ +
[
+    {
+        "id": 1,
+        "name": "Ed Spencer",
+        "email": "ed@sencha.com"
+    },
+    {
+        "id": 2,
+        "name": "Abe Elias",
+        "email": "abe@sencha.com"
+    }
+]
+
+ +

Reading other JSON formats

+ +

If you already have your JSON format defined and it doesn't look quite like what we have above, you can usually +pass JsonReader a couple of configuration options to make it parse your format. For example, we can use the +root configuration to parse data that comes back like this:

+ +
{
+    "users": [
+       {
+           "id": 1,
+           "name": "Ed Spencer",
+           "email": "ed@sencha.com"
+       },
+       {
+           "id": 2,
+           "name": "Abe Elias",
+           "email": "abe@sencha.com"
+       }
+    ]
+}
+
+ +

To parse this we just pass in a root configuration that matches the 'users' above:

+ +
reader: {
+    type: 'json',
+    root: 'users'
+}
+
+ +

Sometimes the JSON structure is even more complicated. Document databases like CouchDB often provide metadata +around each record inside a nested structure like this:

+ +
{
+    "total": 122,
+    "offset": 0,
+    "users": [
+        {
+            "id": "ed-spencer-1",
+            "value": 1,
+            "user": {
+                "id": 1,
+                "name": "Ed Spencer",
+                "email": "ed@sencha.com"
+            }
+        }
+    ]
+}
+
+ +

In the case above the record data is nested an additional level inside the "users" array as each "user" item has +additional metadata surrounding it ('id' and 'value' in this case). To parse data out of each "user" item in the +JSON above we need to specify the record configuration like this:

+ +
reader: {
+    type  : 'json',
+    root  : 'users',
+    record: 'user'
+}
+
+ +

Response metadata

+ +

The server can return additional data in its response, such as the total number of records +and the success status of the response. These are typically included in the JSON response +like this:

+ +
{
+    "total": 100,
+    "success": true,
+    "users": [
+        {
+            "id": 1,
+            "name": "Ed Spencer",
+            "email": "ed@sencha.com"
+        }
+    ]
+}
+
+ +

If these properties are present in the JSON response they can be parsed out by the JsonReader and used by the +Store that loaded it. We can set up the names of these properties by specifying a final pair of configuration +options:

+ +
reader: {
+    type : 'json',
+    root : 'users',
+    totalProperty  : 'total',
+    successProperty: 'success'
+}
+
+ +

These final options are not necessary to make the Reader work, but can be useful when the server needs to report +an error or if it needs to indicate that there is a lot of data available of which only a subset is currently being +returned.

+ +
Defined By

Config Options

Other Configs

 
Name of the property within a row object +that contains a record identifier value. Defaults to The id of the model. +I...

Name of the property within a row object +that contains a record identifier value. Defaults to The id of the model. +If an idProperty is explicitly specified it will override that of the one specified +on the model

+
 
True to automatically parse models nested within other models in a response +object. See the Ext.data.reader.Reader in...

True to automatically parse models nested within other models in a response +object. See the Ext.data.reader.Reader intro docs for full explanation. Defaults to true.

+
 

The name of the property which contains a response message. +This property is optional.

+

The name of the property which contains a response message. +This property is optional.

+
 
The optional location within the JSON response that the record data itself can be found at. +See the JsonReader intro ...

The optional location within the JSON response that the record data itself can be found at. +See the JsonReader intro docs for more details. This is not often needed and defaults to undefined.

+
 
Required. The name of the property +which contains the Array of row objects. Defaults to undefined. +An exception wil...

Required. The name of the property +which contains the Array of row objects. Defaults to undefined. +An exception will be thrown if the root property is undefined. The data +packet value for this property should be an empty array to clear the data +or show no data.

+
 
Name of the property from which to +retrieve the success attribute. Defaults to success. See +Ext.data.proxy.Proxy.exc...

Name of the property from which to +retrieve the success attribute. Defaults to success. See +Ext.data.proxy.Proxy.exception +for additional information.

+
 
Name of the property from which to +retrieve the total number of records in the dataset. This is only needed +if the wh...

Name of the property from which to +retrieve the total number of records in the dataset. This is only needed +if the whole dataset is not passed in one go, but is being paged from +the remote server. Defaults to total.

+
 
True to ensure that field names/mappings are treated as literals when +reading values. Defalts to false. +For example, ...

True to ensure that field names/mappings are treated as literals when +reading values. Defalts to false. +For example, by default, using the mapping "foo.bar.baz" will try and read a property foo from the root, then a property bar +from foo, then a property baz from bar. Setting the simple accessors to true will read the property with the name +"foo.bar.baz" direct from the root object.

+
Defined By

Properties

 

DEPRECATED - will be removed in Ext JS 5.0. This is just a copy of this.rawData - use that instead

+

DEPRECATED - will be removed in Ext JS 5.0. This is just a copy of this.rawData - use that instead

+
 

The raw data object that was last passed to readRecords. Stored for further processing if needed

+

The raw data object that was last passed to readRecords. Stored for further processing if needed

+
Defined By

Methods

 
Json( +Object config) + : void

 

+

Parameters

  • config : Object

    Optional config object

    +

Returns

  • void    +
 
Takes a raw response object (as passed to this.read) and returns the useful data segment of it. This must be implemen...

Takes a raw response object (as passed to this.read) and returns the useful data segment of it. This must be implemented by each subclass

+

Parameters

  • response : Object

    The responce object

    +

Returns

  • Object   

    The useful data from the response

    +
 
read( +Object response) + : Ext.data.ResultSet
Reads the given response object. This method normalizes the different types of response object that may be passed +to ...

Reads the given response object. This method normalizes the different types of response object that may be passed +to it, before handing off the reading of records to the readRecords function.

+

Parameters

  • response : Object

    The response object. This may be either an XMLHttpRequest object or a plain JS object

    +

Returns

  • Ext.data.ResultSet   

    The parsed ResultSet object

    +
 
readRecords( +Object data) + : Ext.data.ResultSet
Reads a JSON object and returns a ResultSet. Uses the internal getTotal and getSuccess extractors to +retrieve meta da...

Reads a JSON object and returns a ResultSet. Uses the internal getTotal and getSuccess extractors to +retrieve meta data from the response, and extractData to turn the JSON data into model instances.

+

Parameters

  • data : Object

    The raw JSON data

    +

Returns

  • Ext.data.ResultSet   

    A ResultSet containing model instances and meta data about the results

    +
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