backend.dataproxy.js | |
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this.recline = this.recline || {};
this.recline.Backend = this.recline.Backend || {};
this.recline.Backend.DataProxy = this.recline.Backend.DataProxy || {};
(function(my) {
my.__type__ = 'dataproxy'; | |
URL for the dataproxy | my.dataproxy_url = '//jsonpdataproxy.appspot.com'; |
Timeout for dataproxy (after this time if no response we error) Needed because use JSONP so do not receive e.g. 500 errors | my.timeout = 5000;
|
use either jQuery or Underscore Deferred depending on what is available | var Deferred = _.isUndefined(this.jQuery) ? _.Deferred : jQuery.Deferred; |
loadLoad data from a URL via the DataProxy. Returns array of field names and array of arrays for records | my.fetch = function(dataset) {
var data = {
url: dataset.url,
'max-results': dataset.size || dataset.rows || 1000,
type: dataset.format || ''
};
var jqxhr = jQuery.ajax({
url: my.dataproxy_url,
data: data,
dataType: 'jsonp'
});
var dfd = new Deferred();
_wrapInTimeout(jqxhr).done(function(results) {
if (results.error) {
dfd.reject(results.error);
}
dfd.resolve({
records: results.data,
fields: results.fields,
useMemoryStore: true
});
})
.fail(function(args) {
dfd.reject(args);
});
return dfd.promise();
}; |
_wrapInTimeoutConvenience method providing a crude way to catch backend errors on JSONP calls. Many of backends use JSONP and so will not get error messages and this is a crude way to catch those errors. | var _wrapInTimeout = function(ourFunction) {
var dfd = new Deferred();
var timer = setTimeout(function() {
dfd.reject({
message: 'Request Error: Backend did not respond after ' + (my.timeout / 1000) + ' seconds'
});
}, my.timeout);
ourFunction.done(function(args) {
clearTimeout(timer);
dfd.resolve(args);
})
.fail(function(args) {
clearTimeout(timer);
dfd.reject(args);
})
;
return dfd.promise();
};
}(this.recline.Backend.DataProxy));
|