datasource.js revision fde564a2cb44f0d31d9eb8e59bac8c457f7d8ca6
YUI.add('datasource-base', function(Y) {
/**
* The DataSource utility provides a common configurable interface for widgets to
* access a variety of data, from JavaScript arrays to online database servers.
*
* @module datasource
* @requires base
* @title DataSource Utility
*/
Y.namespace("DataSource");
var LANG = Y.Lang,
/**
* Base class for the YUI DataSource utility.
* @class DataSource
* @extends Base
* @constructor
*/
DSBase = function() {
DSBase.superclass.constructor.apply(this, arguments);
};
/////////////////////////////////////////////////////////////////////////////
//
// DataSource static properties
//
/////////////////////////////////////////////////////////////////////////////
Y.mix(DSBase, {
/**
* Class name.
*
* @property DataSource.NAME
* @type String
* @static
* @final
* @value "DataSource"
*/
NAME: "DataSource",
/////////////////////////////////////////////////////////////////////////////
//
// DataSource Attributes
//
/////////////////////////////////////////////////////////////////////////////
ATTRS: {
/**
* @attribute source
* @description Pointer to live data.
* @type MIXED
* @default null
*/
source: {
value: null
}
},
/**
* Global transaction counter.
*
* @property DataSource._tId
* @type Number
* @static
* @private
* @default 0
*/
_tId: 0,
/**
* Executes a given callback. The third param determines whether to execute
*
* @method DataSource.issueCallback
* @param callback {Object} The callback object.
* @param params {Array} params to be passed to the callback method
* @param error {Boolean} whether an error occurred
* @static
*/
issueCallback: function (response) {
if(response.callback) {
var scope = response.callback.scope || window,
callbackFunc = (response.error && response.callback.failure) || response.callback.success;
if (callbackFunc) {
callbackFunc.apply(scope, [response]);
}
}
}
});
Y.extend(DSBase, Y.Base, {
/**
* @property _queue
* @description Object literal to manage asynchronous request/response
* cycles enabled if queue needs to be managed (asyncMode/xhrConnMode):
<dl>
<dt>interval {Number}</dt>
<dd>Interval ID of in-progress queue.</dd>
<dt>conn</dt>
<dd>In-progress connection identifier (if applicable).</dd>
<dt>requests {Object[]}</dt>
<dd>Array of queued request objects: {request:oRequest, callback:_xhrCallback}.</dd>
</dl>
* @type Object
* @default {interval:null, conn:null, requests:[]}
* @private
*/
_queue: null,
/**
* @method initializer
* @description Internal init() handler.
* @private
*/
initializer: function() {
this._queue = {interval:null, conn:null, requests:[]};
this._initEvents();
},
/**
* @method destructor
* @description Internal destroy() handler.
* @private
*/
destructor: function() {
},
/**
* @method _createEvents
* @description This method creates all the events for this module
* Target and publishes them so we get Event Bubbling.
* @private
*/
_initEvents: function() {
/**
* Fired when a data request is received.
*
* @event request
* @param e {Event.Facade} Event Facade.
* @param o {Object} Object with the following properties:
* <dl>
* <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
* <dt>request (Object)</dt> <dd>The request.</dd>
* <dt>callback (Object)</dt> <dd>The callback object.</dd>
* </dl>
* @preventable _handleRequest
*/
this.publish("request", {defaultFn: this._handleRequest});
/**
* Fired when raw data is received.
*
* @event data
* @param e {Event.Facade} Event Facade.
* @param o {Object} Object with the following properties:
* <dl>
* <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
* <dt>request (Object)</dt> <dd>The request.</dd>
* <dt>callback (Object)</dt> <dd>The callback object.</dd>
* <dt>data (Object)</dt> <dd>The raw data.</dd>
* </dl>
* @preventable _handleData
*/
this.publish("data", {defaultFn: this._handleData});
/**
* Fired when response is returned.
*
* @event response
* @param e {Event.Facade} Event Facade.
* @param o {Object} Object with the following properties:
* <dl>
* <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
* <dt>request (Object)</dt> <dd>The request.</dd>
* <dt>callback (Object)</dt> <dd>The callback object.</dd>
* <dt>data (Object)</dt> <dd>The raw data.</dd>
* <dt>results (Object)</dt> <dd>Parsed results.</dd>
* <dt>meta (Object)</dt> <dd>Parsed meta results data.</dd>
* <dt>error (Boolean)</dt> <dd>Error flag.</dd>
* </dl>
* @preventable _handleResponse
*/
this.publish("response", {defaultFn: this._handleResponse});
/**
* Fired when an error is encountered.
*
* @event error
* @param e {Event.Facade} Event Facade.
* @param o {Object} Object with the following properties:
* <dl>
* <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
* <dt>request (Object)</dt> <dd>The request.</dd>
* <dt>callback (Object)</dt> <dd>The callback object.</dd>
* <dt>data (Object)</dt> <dd>The raw data (if available).</dd>
* <dt>results (Object)</dt> <dd>Parsed results (if available).</dd>
* <dt>meta (Object)</dt> <dd>Parsed meta results data (if available).</dd>
* <dt>error (Boolean)</dt> <dd>Error flag.</dd>
* </dl>
*/
},
/**
* Overridable default <code>request</code> event handler manages request/response
* transaction. Must fire <code>response</code> event when response is received. This
* method should be implemented by subclasses to achieve more complex
* behavior such as accessing remote data.
*
* @method _handleRequest
* @param e {Event.Facade} Event Facade.
* @param o {Object} Object with the following properties:
* <dl>
* <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
* <dt>request (Object)</dt> <dd>The request.</dd>
* <dt>callback (Object)</dt> <dd>The callback object.</dd>
* </dl>
* @protected
*/
_handleRequest: function(e, o) {
var data = this.get("source");
// Problematic data
if(LANG.isUndefined(data)) {
o.error = true;
}
if(o.error) {
this.fire("error", null, o);
}
this.fire("data", null, Y.mix(o, {data:data}));
},
/**
* Overridable default <code>data</code> event handler normalizes raw data
* into a response that includes results and meta properties.
*
* @method _handleData
* @param e {Event.Facade} Event Facade.
* @param o {Object} Object with the following properties:
* <dl>
* <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
* <dt>request (Object)</dt> <dd>The request.</dd>
* <dt>callback (Object)</dt> <dd>The callback object.</dd>
* <dt>data (Object)</dt> <dd>The raw response data.</dd>
* </dl>
* @protected
*/
_handleData: function(e, o) {
// Pass through data as-is
o.results = o.data;
// Normalize
if(!o.results) {
o.results = [];
}
if(!o.meta) {
o.meta = {};
}
this.fire("response", null, o);
},
/**
* Overridable default <code>response</code> event handler returns data as a
* normalized response to callabck.
*
* @method _handleResponse
* @param e {Event.Facade} Event Facade.
* @param o {Object} Object with the following properties:
* <dl>
* <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
* <dt>request (Object)</dt> <dd>The request.</dd>
* <dt>callback (Object)</dt> <dd>The callback object.</dd>
* <dt>data (Object)</dt> <dd>Raw data.</dd>
* <dt>results (Object)</dt> <dd>Parsed results.</dd>
* <dt>meta (Object)</dt> <dd>Parsed meta data.</dd>
* </dl>
* @protected
*/
_handleResponse: function(e, o) {
// Send the response back to the callback
DSBase.issueCallback(o);
},
/**
* Generates a unique transaction ID and fires <code>request</code> event.
*
* @method sendRequest
* @param request {Object} Request.
* @param callback {Object} An object literal with the following properties:
* <dl>
* <dt><code>success</code></dt>
* <dd>The function to call when the data is ready.</dd>
* <dt><code>failure</code></dt>
* <dd>The function to call upon a response failure condition.</dd>
* <dt><code>scope</code></dt>
* <dd>The object to serve as the scope for the success and failure handlers.</dd>
* <dt><code>argument</code></dt>
* <dd>Arbitrary data payload that will be passed back to the success and failure handlers.</dd>
* </dl>
* @return {Number} Transaction ID.
*/
sendRequest: function(request, callback) {
var tId = DSBase._tId++;
this.fire("request", null, {tId:tId, request:request,callback:callback});
return tId;
}
});
Y.DataSource = DSBase;
}, '@VERSION@' ,{requires:['base']});
YUI.add('datasource-xhr', function(Y) {
/**
* The DataSource utility provides a common configurable interface for widgets to
* access a variety of data, from JavaScript arrays to online database servers.
*
* @module datasource-xhr
* @requires datasource-base
* @title DataSource XHR Submodule
*/
var LANG = Y.Lang,
/**
* XHR subclass for the YUI DataSource utility.
* @class DataSource.XHR
* @extends DataSource
* @constructor
*/
XHR = function() {
XHR.superclass.constructor.apply(this, arguments);
};
/////////////////////////////////////////////////////////////////////////////
//
// DataSource.XHR static properties
//
/////////////////////////////////////////////////////////////////////////////
Y.mix(XHR, {
/**
* Class name.
*
* @property DataSource.XHR.NAME
* @type String
* @static
* @final
* @value "DataSource.XHR"
*/
NAME: "DataSource.XHR",
/////////////////////////////////////////////////////////////////////////////
//
// DataSource.XHR Attributes
//
/////////////////////////////////////////////////////////////////////////////
ATTRS: {
/**
* Pointer to IO Utility.
*
* @attribute io
* @type Y.io
* @default Y.io
*/
io: {
value: Y.io
}
}
});
Y.extend(XHR, Y.DataSource, {
/**
* Overriding <code>request</code> event handler passes query string to IO. Fires
* <code>response</code> event when response is received.
*
* @method _handleRequest
* @param e {Event.Facade} Event Facade.
* @param o {Object} Object with the following properties:
* <dl>
* <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
* <dt>request (Object)</dt> <dd>The request.</dd>
* <dt>callback (Object)</dt> <dd>The callback object.</dd>
* </dl>
* @protected
*/
_handleRequest: function(e, o) {
var uri = this.get("source"),
cfg = {
on: {
success: function (id, response, o) {
this.fire("data", null, Y.mix(o, {data:response}));
//{tId:args.tId, request:args.request, callback:args.callback, response:response}
//this.handleResponse(args.tId, args.request, args.callback, response);
},
failure: function (id, response, o) {
o.error = true;
this.fire("error", null, Y.mix(o, {data:response}));
this.fire("data", null, Y.mix(o, {data:response}));
//{tId:args.tId, request:args.request, callback:args.callback, response:response}
//this.handleResponse(args.tId, args.request, args.callback, response);
}
},
context: this,
arguments: {
tId: o.tId,
request: o.request,
callback: o.callback
}
};
this.get("io")(uri, cfg);
return o.tId;
}
});
Y.DataSource.XHR = XHR;
}, '@VERSION@' ,{requires:['datasource-base']});
YUI.add('datasource-cache', function(Y) {
/**
* Extends DataSource with caching functionality.
*
* @module datasource-cache
* @requires datasource-base,cache
* @title DataSource Cache Extension
*/
var LANG = Y.Lang,
BASE = Y.DataSource,
/**
* Adds cacheability to the YUI DataSource utility.
* @class Cacheable
*/
Cacheable = function() {};
Cacheable.ATTRS = {
/////////////////////////////////////////////////////////////////////////////
//
// DataSource Attributes
//
/////////////////////////////////////////////////////////////////////////////
/**
* Instance of Y.Cache. Caching is useful to reduce the number of server
* connections. Recommended only for data sources that return comprehensive
* results for queries or when stale data is not an issue.
*
* @attribute cache
* @type Y.Cache
* @default null
*/
cache: {
value: null,
validator: function(value) {
return ((value instanceof Y.Cache) || (value === null));
},
set: function(value) {
this.on("request", this._beforeRequest);
this.on("response", this._beforeResponse);
//TODO: Cleanup for destroy()?
}
}
};
Cacheable.prototype = {
/**
* First look for cached response, then send request to live data.
*
* @method _beforeRequest
* @param e {Event.Facade} Event Facade.
* @param o {Object} Object with the following properties:
* <dl>
* <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
* <dt>request (Object)</dt> <dd>The request.</dd>
* <dt>callback (Object)</dt> <dd>The callback object.</dd>
* </dl>
* @protected
*/
_beforeRequest: function(e, o) {
// Is response already in the Cache?
var entry = (this.get("cache") && this.get("cache").retrieve(o.request, o.callback)) || null;
if(entry && entry.response) {
e.stopImmediatePropagation();
this.fire("response", null, Y.mix(o, entry.response));
//BASE.issueCallback(entry.response);
//return new Y.Do.Halt("msg", "newRetVal");
}
},
/**
* Adds data to cache before returning data.
*
* @method _beforeResponse
* @param e {Event.Facade} Event Facade.
* @param o {Object} Object with the following properties:
* <dl>
* <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
* <dt>request (Object)</dt> <dd>The request.</dd>
* <dt>callback (Object)</dt> <dd>The callback object.</dd>
* <dt>data (Object)</dt> <dd>Raw data.</dd>
* <dt>results (Object)</dt> <dd>Parsed results.</dd>
* <dt>meta (Object)</dt> <dd>Parsed meta data.</dd>
* </dl>
* @protected
*/
_beforeResponse: function(e, o) {
// Add to Cache before returning
if(this.get("cache")) {
this.get("cache").add(o.request, o, (o.callback && o.callback.argument));
}
}
};
Y.Base.build(BASE, [Cacheable], {
dynamic: false
});
}, '@VERSION@' ,{requires:['datasource-base']});
YUI.add('datasource-dataparser', function(Y) {
/**
* Extends DataSource with schema-based parsing functionality.
*
* @module datasource-dataparser
* @requires datasource-base,dataparser-base
* @title DataSource DataParser Extension
*/
var LANG = Y.Lang,
BASE = Y.DataSource,
/**
* Adds parsability to the YUI DataSource utility.
* @class Parsable
*/
Parsable = function() {};
Parsable.ATTRS = {
/////////////////////////////////////////////////////////////////////////////
//
// DataSource Attributes
//
/////////////////////////////////////////////////////////////////////////////
/**
* Instance of DataParser.
*
* @attribute parser
* @type Y.DataParser.Base
* @default null
*/
parser: {
value: null,
validator: function(value) {
return ((value instanceof Y.DataParser.Base) || (value === null));
}
}
};
Parsable.prototype = {
/**
* Overriding <code>data</code> event handler parses raw data into a normalized response.
*
* @method _handleData
* @param e {Event.Facade} Event Facade.
* @param o {Object} Object with the following properties:
* <dl>
* <dt>tId (Number)</dt> <dd>Unique transaction ID.</dd>
* <dt>request (Object)</dt> <dd>The request.</dd>
* <dt>callback (Object)</dt> <dd>The callback object.</dd>
* <dt>data (Object)</dt> <dd>The raw response.</dd>
* </dl>
* @protected
*/
_handleData: function(e, o) {
var response = (this.get("parser") && this.get("parser").parse(o.data));
if(!response) {
response = {
meta: {},
results: o.data
};
}
this.fire("response", null, Y.mix(o, response));
}
};
Y.Base.build(BASE, [Parsable], {
dynamic: false
});
}, '@VERSION@' ,{requires:['datasource', 'dataparser']});
YUI.add('datasource-polling', function(Y) {
/**
* Extends DataSource with polling functionality.
*
* @module datasource-polling
* @requires datasource-base
* @title DataSource Polling Extension
*/
var LANG = Y.Lang,
BASE = Y.DataSource,
/**
* Adds polling to the YUI DataSource utility.
* @class Pollable
*/
Pollable = function() {};
Pollable.prototype = {
/**
* @property _intervals
* @description Array of polling interval IDs that have been enabled,
* stored here to be able to clear all intervals.
* @private
*/
_intervals: null,
/**
* Sets up a polling mechanism to send requests at set intervals and forward
* responses to given callback.
*
* @method setInterval
* @param msec {Number} Length of interval in milliseconds.
* @param request {Object} Request object.
* @param callback {Object} An object literal with the following properties:
* <dl>
* <dt><code>success</code></dt>
* <dd>The function to call when the data is ready.</dd>
* <dt><code>failure</code></dt>
* <dd>The function to call upon a response failure condition.</dd>
* <dt><code>scope</code></dt>
* <dd>The object to serve as the scope for the success and failure handlers.</dd>
* <dt><code>argument</code></dt>
* <dd>Arbitrary data that will be passed back to the success and failure handlers.</dd>
* </dl>
* @return {Number} Interval ID.
*/
setInterval: function(msec, request, callback) {
if(LANG.isNumber(msec) && (msec >= 0)) {
var self = this,
id = setInterval(function() {
self.sendRequest(request, callback);
//self._makeConnection(request, callback);
}, msec);
if(!this._intervals) {
this._intervals = [];
}
this._intervals.push(id);
return id;
}
else {
}
},
/**
* Disables polling mechanism associated with the given interval ID.
*
* @method clearInterval
* @param id {Number} Interval ID.
*/
clearInterval: function(id) {
// Remove from tracker if there
var tracker = this._intervals || [],
i = tracker.length-1;
for(; i>-1; i--) {
if(tracker[i] === id) {
tracker.splice(i,1);
clearInterval(id);
}
}
}
};
Y.Base.build(BASE, [Pollable], {
dynamic: false
});
}, '@VERSION@' ,{requires:['datasource-base']});
YUI.add('datasource', function(Y){}, '@VERSION@' ,{use:['datasource-base','datasource-xhr','datasource-cache', 'datasource-dataparser', 'datasource-polling']});