Class YAHOO.widget.DataSource

Package:	YAHOO.widget
Class:	DataSource
Extends:	Object
Subclasses:	DS_JSArray, DS_JSFunction, DS_XHR
Defined In:	autocomplete.js

The DataSource classes manages sending a request and returning response from a live database. Supported data include local JavaScript arrays and objects and databases accessible via XHR connections. Supported response formats include JavaScript arrays, JSON, XML, and flat-file textual data.

Public Properties

Property		Defined By
	ERROR_DATANULL : String	DataSource
	<static> Error message for null data responses.	DataSource
	ERROR_DATAPARSE : String	DataSource
	<static> Error message for data responses with parsing errors.	DataSource
	maxCacheEntries : Number	DataSource
	Max size of the local cache. Set to 0 to turn off caching. Caching is useful to reduce the number of server connect...	DataSource
	queryMatchCase : Boolean	DataSource
	Enables query case-sensitivity matching. If caching is on and queryMatchCase is true, queries will only return result...	DataSource
	queryMatchContains : Boolean	DataSource
	Use this to equate cache matching with the type of matching done by your live data source. If caching is on and query...	DataSource
	queryMatchSubset : Boolean	DataSource
	Enables query subset matching. If caching is on and queryMatchSubset is true, substrings of queries will return match...	DataSource

Public Methods

Method		Defined By
	DataSource()	DataSource
		DataSource
	doQuery(`oCallbackFn {HTMLFunction}`, `sQuery {String}`, `oParent {Object}`) : void	DataSource
	Abstract method implemented by subclasses to make a query to the live data source. Must call the callback function wi...	DataSource
	flushCache() : void	DataSource
	Flushes cache.	DataSource
	getResults(`oCallbackFn {HTMLFunction}`, `sQuery {String}`, `oParent {Object}`) : void	DataSource
	Retrieves query results, first checking the local cache, then making the query request to the live data source as def...	DataSource
	toString() : String	DataSource
	Public accessor to the unique name of the DataSource instance.	DataSource

Public Events

Event		Defined By
	cacheFlushEvent : (`oSelf {Object}`)	DataSource
	Fired when the local cache is flushed.	DataSource
	cacheQueryEvent : (`oSelf {Object}`, `oParent {Object}`, `sQuery {String}`)	DataSource
	Fired when a query is made to the local cache.	DataSource
	dataErrorEvent : (`oSelf {Object}`, `oParent {Object}`, `sQuery {String}`, `sMsg {String}`)	DataSource
	Fired when an error is encountered with the live data source.	DataSource
	getCachedResultsEvent : (`oSelf {Object}`, `oParent {Object}`, `sQuery {String}`, `aResults {Object[]}`)	DataSource
	Fired when data is retrieved from the local cache.	DataSource
	getResultsEvent : (`oSelf {Object}`, `oParent {Object}`, `sQuery {String}`, `aResults {Object[]}`)	DataSource
	Fired when data is retrieved from the live data source.	DataSource
	queryEvent : (`oSelf {Object}`, `oParent {Object}`, `sQuery {String}`)	DataSource
	Fired when a query is made to the live data source.	DataSource

Property Details

ERROR_DATANULL

public String ERROR_DATANULL

<static> Error message for null data responses.

This property is defined by DataSource.

ERROR_DATAPARSE

public String ERROR_DATAPARSE

<static> Error message for data responses with parsing errors.

This property is defined by DataSource.

maxCacheEntries

public Number maxCacheEntries

Max size of the local cache. Set to 0 to turn off caching. 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.

This property is defined by DataSource.

queryMatchCase

public Boolean queryMatchCase

Enables query case-sensitivity matching. If caching is on and queryMatchCase is true, queries will only return results for case-sensitive matches.

This property is defined by DataSource.

queryMatchContains

public Boolean queryMatchContains

Use this to equate cache matching with the type of matching done by your live data source. If caching is on and queryMatchContains is true, the cache returns results that "contain" the query string. By default, queryMatchContains is set to false, meaning the cache only returns results that "start with" the query string.

This property is defined by DataSource.

queryMatchSubset

public Boolean queryMatchSubset

Enables query subset matching. If caching is on and queryMatchSubset is true, substrings of queries will return matching cached results. For instance, if the first query is for "abc" susequent queries that start with "abc", like "abcd", will be queried against the cache, and not the live data source. Recommended only for DataSources that return comprehensive results for queries with very few characters.

This property is defined by DataSource.

Constructor Details

DataSource

public function DataSource()

Parameters:

None.

Method Details

doQuery

public function doQuery(oCallbackFn {HTMLFunction}, sQuery {String}, oParent {Object})

Abstract method implemented by subclasses to make a query to the live data source. Must call the callback function with the response returned from the query. Populates cache (if enabled).

Parameters:

{HTMLFunction} : oCallbackFn
Callback function implemented by oParent to which to return results.
{String} : sQuery
Query string.
{Object} : oParent
The object instance that has requested data.

Returns:

void

This method is defined by DataSource.

flushCache

public function flushCache()

Flushes cache.

Parameters:

None.

Returns:

void

This method is defined by DataSource.

getResults

public function getResults(oCallbackFn {HTMLFunction}, sQuery {String}, oParent {Object})

Retrieves query results, first checking the local cache, then making the query request to the live data source as defined by the function doQuery.

Parameters:

{HTMLFunction} : oCallbackFn
Callback function defined by oParent object to which to return results.
{String} : sQuery
Query string.
{Object} : oParent
The object instance that has requested data.

Returns:

void

This method is defined by DataSource.

toString

public function toString()

Public accessor to the unique name of the DataSource instance.

Parameters:

None.

Returns:

String
Unique name of the DataSource instance

This method is defined by DataSource.

Event Details

cacheFlushEvent

public event cacheFlushEvent

Fired when the local cache is flushed.

Subscribers will be called with the following parameters:

{Object} : oSelf
The DataSource instance

This event is defined by DataSource.

cacheQueryEvent

public event cacheQueryEvent

Fired when a query is made to the local cache.

Subscribers will be called with the following parameters:

{Object} : oSelf
The DataSource instance.
{Object} : oParent
The requesting object.
{String} : sQuery
The query string.

This event is defined by DataSource.

dataErrorEvent

public event dataErrorEvent

Fired when an error is encountered with the live data source.

Subscribers will be called with the following parameters:

{Object} : oSelf
The DataSource instance.
{Object} : oParent
The requesting object.
{String} : sQuery
The query string.
{String} : sMsg
Error message string

This event is defined by DataSource.

getCachedResultsEvent

public event getCachedResultsEvent

Fired when data is retrieved from the local cache.

Subscribers will be called with the following parameters:

{Object} : oSelf
The DataSource instance.
{Object} : oParent
The requesting object.
{String} : sQuery
The query string.
{Object[]} : aResults
Array of result objects.

This event is defined by DataSource.

getResultsEvent

public event getResultsEvent

Fired when data is retrieved from the live data source.

Subscribers will be called with the following parameters:

{Object} : oSelf
The DataSource instance.
{Object} : oParent
The requesting object.
{String} : sQuery
The query string.
{Object[]} : aResults
Array of result objects.

This event is defined by DataSource.

queryEvent

public event queryEvent

Fired when a query is made to the live data source.

Subscribers will be called with the following parameters:

{Object} : oSelf
The DataSource instance.
{Object} : oParent
The requesting object.
{String} : sQuery
The query string.

This event is defined by DataSource.

yui-ext - Copyright © 2006 Jack Slocum. | Yahoo! UI - Copyright © 2006 Yahoo! Inc.
All rights reserved.