1 | /* |
---|
2 | * Ext JS Library 2.2.1 |
---|
3 | * Copyright(c) 2006-2009, Ext JS, LLC. |
---|
4 | * licensing@extjs.com |
---|
5 | * |
---|
6 | * http://extjs.com/license |
---|
7 | */ |
---|
8 | |
---|
9 | /** |
---|
10 | * @class Ext.data.JsonReader |
---|
11 | * @extends Ext.data.DataReader |
---|
12 | * Data reader class to create an Array of {@link Ext.data.Record} objects from a JSON response |
---|
13 | * based on mappings in a provided {@link Ext.data.Record} constructor.<br> |
---|
14 | * <p> |
---|
15 | * Example code: |
---|
16 | * <pre><code> |
---|
17 | var Employee = Ext.data.Record.create([ |
---|
18 | {name: 'firstname'}, // Map the Record's "firstname" field to the row object's key of the same name |
---|
19 | {name: 'job', mapping: 'occupation'} // Map the "job" field to the row object's "occupation" key |
---|
20 | ]); |
---|
21 | var myReader = new Ext.data.JsonReader({ |
---|
22 | totalProperty: "results", // The property which contains the total dataset size (optional) |
---|
23 | root: "rows", // The property which contains an Array of row objects |
---|
24 | id: "id" // The property within each row object that provides an ID for the record (optional) |
---|
25 | }, Employee); |
---|
26 | </code></pre> |
---|
27 | * <p> |
---|
28 | * This would consume a JSON object of the form: |
---|
29 | * <pre><code> |
---|
30 | { |
---|
31 | results: 2, |
---|
32 | rows: [ |
---|
33 | { id: 1, firstname: 'Bill', occupation: 'Gardener' }, // a row object |
---|
34 | { id: 2, firstname: 'Ben' , occupation: 'Horticulturalist' } // another row object |
---|
35 | ] |
---|
36 | } |
---|
37 | </code></pre> |
---|
38 | * <p>It is possible to change a JsonReader's metadata at any time by including a |
---|
39 | * <b><tt>metaData</tt></b> property in the data object. If this is detected in the |
---|
40 | * object, a {@link Ext.data.Store Store} object using this Reader will reconfigure |
---|
41 | * itself to use the newly provided field definition and fire its |
---|
42 | * {@link Ext.data.Store#metachange metachange} event. In |
---|
43 | * undergoing this change, the Store sets its {@link Ext.data.Store#sortInfo sortInfo} property |
---|
44 | * from the <tt>sortInfo</tt> property in the new metadata. Note that reconfiguring a Store |
---|
45 | * potentially invalidates objects which may refer to Fields or Records which no longer exist.</p> |
---|
46 | * |
---|
47 | * <p>The <b><tt>metaData</tt></b> property may contain any of the configuration |
---|
48 | * options for this class. Additionally, it may contain a <b><tt>fields</tt></b> |
---|
49 | * property which the JsonReader will use as an argument to {@link Ext.data.Record#create} |
---|
50 | * to configure the layout of the Records which it will produce.<p> |
---|
51 | * Using the <b><tt>metaData</tt></b> property, and the Store's {@link Ext.data.Store#metachange metachange} event, |
---|
52 | * it is possible to have a Store-driven control initialize itself. The metachange |
---|
53 | * event handler may interrogate the <b><tt>metaData</tt></b> property (which |
---|
54 | * may contain any user-defined properties needed) and the <b><tt>metaData.fields</tt></b> |
---|
55 | * property to perform any configuration required.</p> |
---|
56 | * |
---|
57 | * <p>To use this facility to send the same data as the above example without |
---|
58 | * having to code the creation of the Record constructor, you would create the |
---|
59 | * JsonReader like this:</p><pre><code> |
---|
60 | var myReader = new Ext.data.JsonReader(); |
---|
61 | </code></pre> |
---|
62 | * <p>The first data packet from the server would configure the reader by |
---|
63 | * containing a metaData property as well as the data:</p><pre><code> |
---|
64 | { |
---|
65 | metaData: { |
---|
66 | totalProperty: 'results', |
---|
67 | root: 'rows', |
---|
68 | id: 'id', |
---|
69 | fields: [ |
---|
70 | {name: 'name'}, |
---|
71 | {name: 'occupation'} |
---|
72 | ] |
---|
73 | }, |
---|
74 | results: 2, |
---|
75 | rows: [ |
---|
76 | { 'id': 1, 'name': 'Bill', occupation: 'Gardener' }, |
---|
77 | { 'id': 2, 'name': 'Ben', occupation: 'Horticulturalist' } |
---|
78 | ] |
---|
79 | } |
---|
80 | </code></pre> |
---|
81 | * @cfg {String} totalProperty Name of the property from which to retrieve the total number of records |
---|
82 | * in the dataset. This is only needed if the whole dataset is not passed in one go, but is being |
---|
83 | * paged from the remote server. |
---|
84 | * @cfg {String} successProperty Name of the property from which to retrieve the success attribute used by forms. |
---|
85 | * @cfg {String} root name of the property which contains the Array of row objects. |
---|
86 | * @cfg {String} id Name of the property within a row object that contains a record identifier value. |
---|
87 | * @constructor |
---|
88 | * Create a new JsonReader |
---|
89 | * @param {Object} meta Metadata configuration options. |
---|
90 | * @param {Object} recordType Either an Array of field definition objects as passed to |
---|
91 | * {@link Ext.data.Record#create}, or a {@link Ext.data.Record Record} constructor created using {@link Ext.data.Record#create}. |
---|
92 | */ |
---|
93 | Ext.data.JsonReader = function(meta, recordType){ |
---|
94 | meta = meta || {}; |
---|
95 | Ext.data.JsonReader.superclass.constructor.call(this, meta, recordType || meta.fields); |
---|
96 | }; |
---|
97 | Ext.extend(Ext.data.JsonReader, Ext.data.DataReader, { |
---|
98 | /** |
---|
99 | * This JsonReader's metadata as passed to the constructor, or as passed in |
---|
100 | * the last data packet's <b><tt>metaData</tt></b> property. |
---|
101 | * @type Mixed |
---|
102 | * @property meta |
---|
103 | */ |
---|
104 | /** |
---|
105 | * This method is only used by a DataProxy which has retrieved data from a remote server. |
---|
106 | * @param {Object} response The XHR object which contains the JSON data in its responseText. |
---|
107 | * @return {Object} data A data block which is used by an Ext.data.Store object as |
---|
108 | * a cache of Ext.data.Records. |
---|
109 | */ |
---|
110 | read : function(response){ |
---|
111 | var json = response.responseText; |
---|
112 | var o = eval("("+json+")"); |
---|
113 | if(!o) { |
---|
114 | throw {message: "JsonReader.read: Json object not found"}; |
---|
115 | } |
---|
116 | return this.readRecords(o); |
---|
117 | }, |
---|
118 | |
---|
119 | // private function a store will implement |
---|
120 | onMetaChange : function(meta, recordType, o){ |
---|
121 | |
---|
122 | }, |
---|
123 | |
---|
124 | /** |
---|
125 | * @ignore |
---|
126 | */ |
---|
127 | simpleAccess: function(obj, subsc) { |
---|
128 | return obj[subsc]; |
---|
129 | }, |
---|
130 | |
---|
131 | /** |
---|
132 | * @ignore |
---|
133 | */ |
---|
134 | getJsonAccessor: function(){ |
---|
135 | var re = /[\[\.]/; |
---|
136 | return function(expr) { |
---|
137 | try { |
---|
138 | return(re.test(expr)) |
---|
139 | ? new Function("obj", "return obj." + expr) |
---|
140 | : function(obj){ |
---|
141 | return obj[expr]; |
---|
142 | }; |
---|
143 | } catch(e){} |
---|
144 | return Ext.emptyFn; |
---|
145 | }; |
---|
146 | }(), |
---|
147 | |
---|
148 | /** |
---|
149 | * Create a data block containing Ext.data.Records from a JSON object. |
---|
150 | * @param {Object} o An object which contains an Array of row objects in the property specified |
---|
151 | * in the config as 'root, and optionally a property, specified in the config as 'totalProperty' |
---|
152 | * which contains the total size of the dataset. |
---|
153 | * @return {Object} data A data block which is used by an Ext.data.Store object as |
---|
154 | * a cache of Ext.data.Records. |
---|
155 | */ |
---|
156 | readRecords : function(o){ |
---|
157 | /** |
---|
158 | * After any data loads, the raw JSON data is available for further custom processing. If no data is |
---|
159 | * loaded or there is a load exception this property will be undefined. |
---|
160 | * @type Object |
---|
161 | */ |
---|
162 | this.jsonData = o; |
---|
163 | if(o.metaData){ |
---|
164 | delete this.ef; |
---|
165 | this.meta = o.metaData; |
---|
166 | this.recordType = Ext.data.Record.create(o.metaData.fields); |
---|
167 | this.onMetaChange(this.meta, this.recordType, o); |
---|
168 | } |
---|
169 | var s = this.meta, Record = this.recordType, |
---|
170 | f = Record.prototype.fields, fi = f.items, fl = f.length; |
---|
171 | |
---|
172 | // Generate extraction functions for the totalProperty, the root, the id, and for each field |
---|
173 | if (!this.ef) { |
---|
174 | if(s.totalProperty) { |
---|
175 | this.getTotal = this.getJsonAccessor(s.totalProperty); |
---|
176 | } |
---|
177 | if(s.successProperty) { |
---|
178 | this.getSuccess = this.getJsonAccessor(s.successProperty); |
---|
179 | } |
---|
180 | this.getRoot = s.root ? this.getJsonAccessor(s.root) : function(p){return p;}; |
---|
181 | if (s.id) { |
---|
182 | var g = this.getJsonAccessor(s.id); |
---|
183 | this.getId = function(rec) { |
---|
184 | var r = g(rec); |
---|
185 | return (r === undefined || r === "") ? null : r; |
---|
186 | }; |
---|
187 | } else { |
---|
188 | this.getId = function(){return null;}; |
---|
189 | } |
---|
190 | this.ef = []; |
---|
191 | for(var i = 0; i < fl; i++){ |
---|
192 | f = fi[i]; |
---|
193 | var map = (f.mapping !== undefined && f.mapping !== null) ? f.mapping : f.name; |
---|
194 | this.ef[i] = this.getJsonAccessor(map); |
---|
195 | } |
---|
196 | } |
---|
197 | |
---|
198 | var root = this.getRoot(o), c = root.length, totalRecords = c, success = true; |
---|
199 | if(s.totalProperty){ |
---|
200 | var v = parseInt(this.getTotal(o), 10); |
---|
201 | if(!isNaN(v)){ |
---|
202 | totalRecords = v; |
---|
203 | } |
---|
204 | } |
---|
205 | if(s.successProperty){ |
---|
206 | var v = this.getSuccess(o); |
---|
207 | if(v === false || v === 'false'){ |
---|
208 | success = false; |
---|
209 | } |
---|
210 | } |
---|
211 | var records = []; |
---|
212 | for(var i = 0; i < c; i++){ |
---|
213 | var n = root[i]; |
---|
214 | var values = {}; |
---|
215 | var id = this.getId(n); |
---|
216 | for(var j = 0; j < fl; j++){ |
---|
217 | f = fi[j]; |
---|
218 | var v = this.ef[j](n); |
---|
219 | values[f.name] = f.convert((v !== undefined) ? v : f.defaultValue, n); |
---|
220 | } |
---|
221 | var record = new Record(values, id); |
---|
222 | record.json = n; |
---|
223 | records[i] = record; |
---|
224 | } |
---|
225 | return { |
---|
226 | success : success, |
---|
227 | records : records, |
---|
228 | totalRecords : totalRecords |
---|
229 | }; |
---|
230 | } |
---|
231 | }); |
---|