datahub/src/backend/dataproxy.js
Rufus Pollock df79583bde [#50,backend,refactor][s]: complete backend split / rename refactor by removing Backend prefix from Backend classes - fixes #50.
* Backend prefix unnecessary now that everything in recline.Backend module.
2012-02-24 19:17:51 +00:00

86 lines
2.5 KiB
JavaScript

this.recline = this.recline || {};
this.recline.Backend = this.recline.Backend || {};
(function($, my) {
// ## DataProxy Backend
//
// For connecting to [DataProxy-s](http://github.com/okfn/dataproxy).
//
// When initializing the DataProxy backend you can set the following attributes:
//
// * dataproxy: {url-to-proxy} (optional). Defaults to http://jsonpdataproxy.appspot.com
//
// Datasets using using this backend should set the following attributes:
//
// * url: (required) url-of-data-to-proxy
// * format: (optional) csv | xls (defaults to csv if not specified)
//
// Note that this is a **read-only** backend.
my.DataProxy = Backbone.Model.extend({
defaults: {
dataproxy_url: 'http://jsonpdataproxy.appspot.com'
},
sync: function(method, model, options) {
var self = this;
if (method === "read") {
if (model.__type__ == 'Dataset') {
var base = self.get('dataproxy_url');
// TODO: should we cache for extra efficiency
var data = {
url: model.get('url')
, 'max-results': 1
, type: model.get('format') || 'csv'
};
var jqxhr = $.ajax({
url: base
, data: data
, dataType: 'jsonp'
});
var dfd = $.Deferred();
my.wrapInTimeout(jqxhr).done(function(results) {
model.fields.reset(_.map(results.fields, function(fieldId) {
return {id: fieldId};
})
);
dfd.resolve(model, jqxhr);
})
.fail(function(arguments) {
dfd.reject(arguments);
});
return dfd.promise();
}
} else {
alert('This backend only supports read operations');
}
},
query: function(dataset, queryObj) {
var base = this.get('dataproxy_url');
var data = {
url: dataset.get('url')
, 'max-results': queryObj.size
, type: dataset.get('format')
};
var jqxhr = $.ajax({
url: base
, data: data
, dataType: 'jsonp'
});
var dfd = $.Deferred();
jqxhr.done(function(results) {
var _out = _.map(results.data, function(doc) {
var tmp = {};
_.each(results.fields, function(key, idx) {
tmp[key] = doc[idx];
});
return tmp;
});
dfd.resolve(_out);
});
return dfd.promise();
}
});
recline.Model.backends['dataproxy'] = new my.DataProxy();
}(jQuery, this.recline.Backend));