/*!
 * Ext JS Library 3.2.1
 * Copyright(c) 2006-2010 Ext JS, Inc.
 * licensing@extjs.com
 * http://www.extjs.com/license
 */
/** * @class Ext.data.DataWriter *

Ext.data.DataWriter facilitates create, update, and destroy actions between * an Ext.data.Store and a server-side framework. A Writer enabled Store will * automatically manage the Ajax requests to perform CRUD actions on a Store.

*

Ext.data.DataWriter is an abstract base class which is intended to be extended * and should not be created directly. For existing implementations, see * {@link Ext.data.JsonWriter}.

*

Creating a writer is simple:

*

var writer = new Ext.data.JsonWriter({
    encode: false   // <--- false causes data to be printed to jsonData config-property of Ext.Ajax#reqeust
});
 * 
* *

Same old JsonReader as Ext-2.x:

*

var reader = new Ext.data.JsonReader({idProperty: 'id'}, [{name: 'first'}, {name: 'last'}, {name: 'email'}]);
 * 
* *

The proxy for a writer enabled store can be configured with a simple url:

*

// Create a standard HttpProxy instance.
var proxy = new Ext.data.HttpProxy({
    url: 'app.php/users'    // <--- Supports "provides"-type urls, such as '/users.json', '/products.xml' (Hello Rails/Merb)
});
 * 
*

For finer grained control, the proxy may also be configured with an API:

*

// Maximum flexibility with the API-configuration
var proxy = new Ext.data.HttpProxy({
    api: {
        read    : 'app.php/users/read',
        create  : 'app.php/users/create',
        update  : 'app.php/users/update',
        destroy : {  // <--- Supports object-syntax as well
            url: 'app.php/users/destroy',
            method: "DELETE"
        }
    }
});
 * 
*

Pulling it all together into a Writer-enabled Store:

*

var store = new Ext.data.Store({
    proxy: proxy,
    reader: reader,
    writer: writer,
    autoLoad: true,
    autoSave: true  // -- Cell-level updates.
});
 * 
*

Initiating write-actions automatically, using the existing Ext2.0 Store/Record API:

*

var rec = store.getAt(0);
rec.set('email', 'foo@bar.com');  // <--- Immediately initiates an UPDATE action through configured proxy.

store.remove(rec);  // <---- Immediately initiates a DESTROY action through configured proxy.
 * 
*

For record/batch updates, use the Store-configuration {@link Ext.data.Store#autoSave autoSave:false}

*

var store = new Ext.data.Store({
    proxy: proxy,
    reader: reader,
    writer: writer,
    autoLoad: true,
    autoSave: false  // -- disable cell-updates
});

var urec = store.getAt(0);
urec.set('email', 'foo@bar.com');

var drec = store.getAt(1);
store.remove(drec);

// Push the button!
store.save();
 * 
* @constructor Create a new DataWriter * @param {Object} meta Metadata configuration options (implementation-specific) * @param {Object} recordType Either an Array of field definition objects as specified * in {@link Ext.data.Record#create}, or an {@link Ext.data.Record} object created * using {@link Ext.data.Record#create}. */ Ext.data.DataWriter = function(config){ Ext.apply(this, config); }; Ext.data.DataWriter.prototype = {
/** * @cfg {Boolean} writeAllFields * false by default. Set true to have DataWriter return ALL fields of a modified * record -- not just those that changed. * false to have DataWriter only request modified fields from a record. */ writeAllFields : false,
/** * @cfg {Boolean} listful * false by default. Set true to have the DataWriter always write HTTP params as a list, * even when acting upon a single record. */ listful : false, // <-- listful is actually not used internally here in DataWriter. @see Ext.data.Store#execute.
/** * Compiles a Store recordset into a data-format defined by an extension such as {@link Ext.data.JsonWriter} or {@link Ext.data.XmlWriter} in preparation for a {@link Ext.data.Api#actions server-write action}. The first two params are similar similar in nature to {@link Ext#apply}, * Where the first parameter is the receiver of paramaters and the second, baseParams, the source. * @param {Object} params The request-params receiver. * @param {Object} baseParams as defined by {@link Ext.data.Store#baseParams}. The baseParms must be encoded by the extending class, eg: {@link Ext.data.JsonWriter}, {@link Ext.data.XmlWriter}. * @param {String} action [{@link Ext.data.Api#actions create|update|destroy}] * @param {Record/Record[]} rs The recordset to write, the subject(s) of the write action. */ apply : function(params, baseParams, action, rs) { var data = [], renderer = action + 'Record'; // TODO implement @cfg listful here if (Ext.isArray(rs)) { Ext.each(rs, function(rec){ data.push(this[renderer](rec)); }, this); } else if (rs instanceof Ext.data.Record) { data = this[renderer](rs); } this.render(params, baseParams, data); },
/** * abstract method meant to be overridden by all DataWriter extensions. It's the extension's job to apply the "data" to the "params". * The data-object provided to render is populated with data according to the meta-info defined in the user's DataReader config, * @param {String} action [Ext.data.Api.actions.create|read|update|destroy] * @param {Record[]} rs Store recordset * @param {Object} params Http params to be sent to server. * @param {Object} data object populated according to DataReader meta-data. */ render : Ext.emptyFn,
/** * @cfg {Function} updateRecord Abstract method that should be implemented in all subclasses * (e.g.: {@link Ext.data.JsonWriter#updateRecord JsonWriter.updateRecord} */ updateRecord : Ext.emptyFn,
/** * @cfg {Function} createRecord Abstract method that should be implemented in all subclasses * (e.g.: {@link Ext.data.JsonWriter#createRecord JsonWriter.createRecord}) */ createRecord : Ext.emptyFn,
/** * @cfg {Function} destroyRecord Abstract method that should be implemented in all subclasses * (e.g.: {@link Ext.data.JsonWriter#destroyRecord JsonWriter.destroyRecord}) */ destroyRecord : Ext.emptyFn,
/** * Converts a Record to a hash, taking into account the state of the Ext.data.Record along with configuration properties * related to its rendering, such as {@link #writeAllFields}, {@link Ext.data.Record#phantom phantom}, {@link Ext.data.Record#getChanges getChanges} and * {@link Ext.data.DataReader#idProperty idProperty} * @param {Ext.data.Record} rec The Record from which to create a hash. * @param {Object} config NOT YET IMPLEMENTED. Will implement an exlude/only configuration for fine-control over which fields do/don't get rendered. * @return {Object} * @protected * TODO Implement excludes/only configuration with 2nd param? */ toHash : function(rec, config) { var map = rec.fields.map, data = {}, raw = (this.writeAllFields === false && rec.phantom === false) ? rec.getChanges() : rec.data, m; Ext.iterate(raw, function(prop, value){ if((m = map[prop])){ data[m.mapping ? m.mapping : m.name] = value; } }); // we don't want to write Ext auto-generated id to hash. Careful not to remove it on Models not having auto-increment pk though. // We can tell its not auto-increment if the user defined a DataReader field for it *and* that field's value is non-empty. // we could also do a RegExp here for the Ext.data.Record AUTO_ID prefix. if (rec.phantom) { if (rec.fields.containsKey(this.meta.idProperty) && Ext.isEmpty(rec.data[this.meta.idProperty])) { delete data[this.meta.idProperty]; } } else { data[this.meta.idProperty] = rec.id } return data; },
/** * Converts a {@link Ext.data.DataWriter#toHash Hashed} {@link Ext.data.Record} to fields-array array suitable * for encoding to xml via XTemplate, eg:
<tpl for="."><{name}>{value}</{name}</tpl>
* eg, non-phantom:
{id: 1, first: 'foo', last: 'bar'} --> [{name: 'id', value: 1}, {name: 'first', value: 'foo'}, {name: 'last', value: 'bar'}]
* {@link Ext.data.Record#phantom Phantom} records will have had their idProperty omitted in {@link #toHash} if determined to be auto-generated. * Non AUTOINCREMENT pks should have been protected. * @param {Hash} data Hashed by Ext.data.DataWriter#toHash * @return {[Object]} Array of attribute-objects. * @protected */ toArray : function(data) { var fields = []; Ext.iterate(data, function(k, v) {fields.push({name: k, value: v});},this); return fields; } };