datahub/src/backend.ckan.js

89 lines
2.4 KiB
JavaScript

this.recline = this.recline || {};
this.recline.Backend = this.recline.Backend || {};
this.recline.Backend.Ckan = this.recline.Backend.Ckan || {};
(function($, my) {
// ## CKAN Backend
//
// This provides connection to the CKAN DataStore (v2)
//
// General notes
//
// * Every dataset must have an id equal to its resource id on the CKAN instance
// * You should set the CKAN API endpoint for requests by setting API_ENDPOINT value on this module (recline.Backend.Ckan.API_ENDPOINT)
my.__type__ = 'ckan';
// Default CKAN API endpoint used for requests (you can change this but it will affect every request!)
my.API_ENDPOINT = 'http://datahub.io/api';
// ### fetch
my.fetch = function(dataset) {
var wrapper = my.DataStore();
var dfd = $.Deferred();
var jqxhr = wrapper.search({resource_id: dataset.id, limit: 0});
jqxhr.done(function(results) {
// map ckan types to our usual types ...
var fields = _.map(results.result.fields, function(field) {
field.type = field.type in CKAN_TYPES_MAP ? CKAN_TYPES_MAP[field.type] : field.type;
return field;
});
var out = {
fields: fields,
useMemoryStore: false
};
dfd.resolve(out);
});
return dfd.promise();
};
my.query = function(queryObj, dataset) {
var wrapper = my.DataStore();
var actualQuery = {
resource_id: dataset.id,
q: queryObj.q,
limit: queryObj.size,
offset: queryObj.from
};
var dfd = $.Deferred();
var jqxhr = wrapper.search(actualQuery);
jqxhr.done(function(results) {
var out = {
total: results.result.total,
hits: results.result.records,
};
dfd.resolve(out);
});
return dfd.promise();
};
// ### DataStore
//
// Simple wrapper around the CKAN DataStore API
//
// @param endpoint: CKAN api endpoint (e.g. http://datahub.io/api)
my.DataStore = function(endpoint) {
var that = {
endpoint: endpoint || my.API_ENDPOINT
};
that.search = function(data) {
var searchUrl = that.endpoint + '/3/action/datastore_search';
var jqxhr = $.ajax({
url: searchUrl,
data: data,
dataType: 'json'
});
return jqxhr;
}
return that;
}
var CKAN_TYPES_MAP = {
'int4': 'integer',
'float8': 'float',
'text': 'string'
};
}(jQuery, this.recline.Backend.Ckan));