File yui3/src/autocomplete/js/autocomplete-sources.js
/**
Mixes support for JSONP and YQL result sources into AutoCompleteBase.
@module autocomplete
@submodule autocomplete-sources
**/
var ACBase = Y.AutoCompleteBase,
Lang = Y.Lang,
_SOURCE_SUCCESS = '_sourceSuccess',
MAX_RESULTS = 'maxResults',
REQUEST_TEMPLATE = 'requestTemplate',
RESULT_LIST_LOCATOR = 'resultListLocator';
// Add prototype properties and methods to AutoCompleteBase.
Y.mix(ACBase.prototype, {
/**
Regular expression used to determine whether a String source is a YQL query.
@property _YQL_SOURCE_REGEX
@type RegExp
@protected
@for AutoCompleteBase
**/
_YQL_SOURCE_REGEX: /^(?:select|set|use)\s+/i,
/**
Runs before AutoCompleteBase's `_createObjectSource()` method and augments
it to support additional object-based source types.
@method _beforeCreateObjectSource
@param {String} source
@protected
@for AutoCompleteBase
**/
_beforeCreateObjectSource: function (source) {
// If the object is a <select> node, use the options as the result
// source.
if (source instanceof Y.Node &&
source.get('nodeName').toLowerCase() === 'select') {
return this._createSelectSource(source);
}
// If the object is a JSONPRequest instance, try to use it as a JSONP
// source.
if (Y.JSONPRequest && source instanceof Y.JSONPRequest) {
return this._createJSONPSource(source);
}
// Fall back to a basic object source.
return this._createObjectSource(source);
},
/**
Creates a DataSource-like object that uses `Y.io` as a source. See the
`source` attribute for more details.
@method _createIOSource
@param {String} source URL.
@return {Object} DataSource-like object.
@protected
@for AutoCompleteBase
**/
_createIOSource: function (source) {
var ioSource = {type: 'io'},
that = this,
ioRequest, lastRequest, loading;
// Private internal _sendRequest method that will be assigned to
// ioSource.sendRequest once io-base and json-parse are available.
function _sendRequest(request) {
var cacheKey = request.request;
// Return immediately on a cached response.
if (that._cache && cacheKey in that._cache) {
that[_SOURCE_SUCCESS](that._cache[cacheKey], request);
return;
}
// Cancel any outstanding requests.
if (ioRequest && ioRequest.isInProgress()) {
ioRequest.abort();
}
ioRequest = Y.io(that._getXHRUrl(source, request), {
on: {
success: function (tid, response) {
var data;
try {
data = Y.JSON.parse(response.responseText);
} catch (ex) {
Y.error('JSON parse error', ex);
}
if (data) {
that._cache && (that._cache[cacheKey] = data);
that[_SOURCE_SUCCESS](data, request);
}
}
}
});
}
ioSource.sendRequest = function (request) {
// Keep track of the most recent request in case there are multiple
// requests while we're waiting for the IO module to load. Only the
// most recent request will be sent.
lastRequest = request;
if (loading) { return; }
loading = true;
// Lazy-load the io-base and json-parse modules if necessary,
// then overwrite the sendRequest method to bypass this check in
// the future.
Y.use('io-base', 'json-parse', function () {
ioSource.sendRequest = _sendRequest;
_sendRequest(lastRequest);
});
};
return ioSource;
},
/**
Creates a DataSource-like object that uses the specified JSONPRequest
instance as a source. See the `source` attribute for more details.
@method _createJSONPSource
@param {JSONPRequest|String} source URL string or JSONPRequest instance.
@return {Object} DataSource-like object.
@protected
@for AutoCompleteBase
**/
_createJSONPSource: function (source) {
var jsonpSource = {type: 'jsonp'},
that = this,
lastRequest, loading;
function _sendRequest(request) {
var cacheKey = request.request,
query = request.query;
if (that._cache && cacheKey in that._cache) {
that[_SOURCE_SUCCESS](that._cache[cacheKey], request);
return;
}
// Hack alert: JSONPRequest currently doesn't support
// per-request callbacks, so we're reaching into the protected
// _config object to make it happen.
//
// This limitation is mentioned in the following JSONP
// enhancement ticket:
//
// http://yuilibrary.com/projects/yui3/ticket/2529371
source._config.on.success = function (data) {
that._cache && (that._cache[cacheKey] = data);
that[_SOURCE_SUCCESS](data, request);
};
source.send(query);
}
jsonpSource.sendRequest = function (request) {
// Keep track of the most recent request in case there are multiple
// requests while we're waiting for the JSONP module to load. Only
// the most recent request will be sent.
lastRequest = request;
if (loading) { return; }
loading = true;
// Lazy-load the JSONP module if necessary, then overwrite the
// sendRequest method to bypass this check in the future.
Y.use('jsonp', function () {
// Turn the source into a JSONPRequest instance if it isn't
// one already.
if (!(source instanceof Y.JSONPRequest)) {
source = new Y.JSONPRequest(source, {
format: Y.bind(that._jsonpFormatter, that)
});
}
jsonpSource.sendRequest = _sendRequest;
_sendRequest(lastRequest);
});
};
return jsonpSource;
},
/**
Creates a DataSource-like object that uses the specified `<select>` node as
a source.
@method _createSelectSource
@param {Node} source YUI Node instance wrapping a `<select>` node.
@return {Object} DataSource-like object.
@protected
@for AutoCompleteBase
**/
_createSelectSource: function (source) {
var that = this;
return {
type: 'select',
sendRequest: function (request) {
var options = [];
source.get('options').each(function (option) {
options.push({
html : option.get('innerHTML'),
index : option.get('index'),
node : option,
selected: option.get('selected'),
text : option.get('text'),
value : option.get('value')
});
});
that[_SOURCE_SUCCESS](options, request);
}
};
},
/**
Creates a DataSource-like object that calls the specified URL or executes
the specified YQL query for results. If the string starts with "select ",
"use ", or "set " (case-insensitive), it's assumed to be a YQL query;
otherwise, it's assumed to be a URL (which may be absolute or relative).
URLs containing a "{callback}" placeholder are assumed to be JSONP URLs; all
others will use XHR. See the `source` attribute for more details.
@method _createStringSource
@param {String} source URL or YQL query.
@return {Object} DataSource-like object.
@protected
@for AutoCompleteBase
**/
_createStringSource: function (source) {
if (this._YQL_SOURCE_REGEX.test(source)) {
// Looks like a YQL query.
return this._createYQLSource(source);
} else if (source.indexOf('{callback}') !== -1) {
// Contains a {callback} param and isn't a YQL query, so it must be
// JSONP.
return this._createJSONPSource(source);
} else {
// Not a YQL query or JSONP, so we'll assume it's an XHR URL.
return this._createIOSource(source);
}
},
/**
Creates a DataSource-like object that uses the specified YQL query string to
create a YQL-based source. See the `source` attribute for details. If no
`resultListLocator` is defined, this method will set a best-guess locator
that might work for many typical YQL queries.
@method _createYQLSource
@param {String} source YQL query.
@return {Object} DataSource-like object.
@protected
@for AutoCompleteBase
**/
_createYQLSource: function (source) {
var that = this,
yqlSource = {type: 'yql'},
lastRequest, loading, yqlRequest;
if (!that.get(RESULT_LIST_LOCATOR)) {
that.set(RESULT_LIST_LOCATOR, that._defaultYQLLocator);
}
function _sendRequest(request) {
var query = request.query,
env = that.get('yqlEnv'),
maxResults = that.get(MAX_RESULTS),
callback, opts, yqlQuery;
yqlQuery = Lang.sub(source, {
maxResults: maxResults > 0 ? maxResults : 1000,
request : request.request,
query : query
});
if (that._cache && yqlQuery in that._cache) {
that[_SOURCE_SUCCESS](that._cache[yqlQuery], request);
return;
}
callback = function (data) {
that._cache && (that._cache[yqlQuery] = data);
that[_SOURCE_SUCCESS](data, request);
};
opts = {proto: that.get('yqlProtocol')};
// Only create a new YQLRequest instance if this is the
// first request. For subsequent requests, we'll reuse the
// original instance.
if (yqlRequest) {
yqlRequest._callback = callback;
yqlRequest._opts = opts;
yqlRequest._params.q = yqlQuery;
if (env) {
yqlRequest._params.env = env;
}
} else {
yqlRequest = new Y.YQLRequest(yqlQuery, {
on: {success: callback},
allowCache: false // temp workaround until JSONP has per-URL callback proxies
}, env ? {env: env} : null, opts);
}
yqlRequest.send();
}
yqlSource.sendRequest = function (request) {
// Keep track of the most recent request in case there are multiple
// requests while we're waiting for the YQL module to load. Only the
// most recent request will be sent.
lastRequest = request;
if (!loading) {
// Lazy-load the YQL module if necessary, then overwrite the
// sendRequest method to bypass this check in the future.
loading = true;
Y.use('yql', function () {
yqlSource.sendRequest = _sendRequest;
_sendRequest(lastRequest);
});
}
};
return yqlSource;
},
/**
Default resultListLocator used when a string-based YQL source is set and the
implementer hasn't already specified one.
@method _defaultYQLLocator
@param {Object} response YQL response object.
@return {Array}
@protected
@for AutoCompleteBase
**/
_defaultYQLLocator: function (response) {
var results = response && response.query && response.query.results,
values;
if (results && Lang.isObject(results)) {
// If there's only a single value on YQL's results object, that
// value almost certainly contains the array of results we want. If
// there are 0 or 2+ values, then the values themselves are most
// likely the results we want.
values = Y.Object.values(results) || [];
results = values.length === 1 ? values[0] : values;
if (!Lang.isArray(results)) {
results = [results];
}
} else {
results = [];
}
return results;
},
/**
Returns a formatted XHR URL based on the specified base _url_, _query_, and
the current _requestTemplate_ if any.
@method _getXHRUrl
@param {String} url Base URL.
@param {Object} request Request object containing `query` and `request`
properties.
@return {String} Formatted URL.
@protected
@for AutoCompleteBase
**/
_getXHRUrl: function (url, request) {
var maxResults = this.get(MAX_RESULTS);
if (request.query !== request.request) {
// Append the request template to the URL.
url += request.request;
}
return Lang.sub(url, {
maxResults: maxResults > 0 ? maxResults : 1000,
query : encodeURIComponent(request.query)
});
},
/**
URL formatter passed to `JSONPRequest` instances.
@method _jsonpFormatter
@param {String} url
@param {String} proxy
@param {String} query
@return {String} Formatted URL
@protected
@for AutoCompleteBase
**/
_jsonpFormatter: function (url, proxy, query) {
var maxResults = this.get(MAX_RESULTS),
requestTemplate = this.get(REQUEST_TEMPLATE);
if (requestTemplate) {
url += requestTemplate(query);
}
return Lang.sub(url, {
callback : proxy,
maxResults: maxResults > 0 ? maxResults : 1000,
query : encodeURIComponent(query)
});
}
});
// Add attributes to AutoCompleteBase.
Y.mix(ACBase.ATTRS, {
/**
YQL environment file URL to load when the `source` is set to a YQL query.
Set this to `null` to use the default Open Data Tables environment file
(http://datatables.org/alltables.env).
@attribute yqlEnv
@type String
@default null
@for AutoCompleteBase
**/
yqlEnv: {
value: null
},
/**
URL protocol to use when the `source` is set to a YQL query.
@attribute yqlProtocol
@type String
@default 'http'
@for AutoCompleteBase
**/
yqlProtocol: {
value: 'http'
}
});
// Tell AutoCompleteBase about the new source types it can now support.
Y.mix(ACBase.SOURCE_TYPES, {
io : '_createIOSource',
jsonp : '_createJSONPSource',
object: '_beforeCreateObjectSource', // Run our version before the base version.
select: '_createSelectSource',
string: '_createStringSource',
yql : '_createYQLSource'
}, true);