terriajs
Version:
Geospatial data visualization platform.
286 lines (244 loc) • 11.6 kB
JavaScript
'use strict';
/*global require*/
var clone = require('terriajs-cesium/Source/Core/clone');
var defined = require('terriajs-cesium/Source/Core/defined');
var defineProperties = require('terriajs-cesium/Source/Core/defineProperties');
var formatError = require('terriajs-cesium/Source/Core/formatError');
var freezeObject = require('terriajs-cesium/Source/Core/freezeObject');
var knockout = require('terriajs-cesium/Source/ThirdParty/knockout');
var loadJson = require('../Core/loadJson');
var proxyCatalogItemUrl = require('./proxyCatalogItemUrl');
var Rectangle = require('terriajs-cesium/Source/Core/Rectangle');
var when = require('terriajs-cesium/Source/ThirdParty/when');
var inherit = require('../Core/inherit');
var WebMapServiceCatalogItem = require('./WebMapServiceCatalogItem');
var GeoJsonCatalogItem = require('./GeoJsonCatalogItem');
var CatalogGroup = require('./CatalogGroup');
var TerriaError = require('../Core/TerriaError');
/**
* A {@link CatalogGroup} representing a collection of layers from a [Socrata](http://Socrata.org) server. Only spatial layers with a defined Map
* visualisation are shown, using WMS.
*
* @alias SocrataCatalogGroup
* @constructor
* @extends CatalogGroup
*
* @param {Terria} terria The Terria instance.
*/
var SocrataCatalogGroup = function(terria) {
CatalogGroup.call(this, terria, 'socrata');
/**
* Gets or sets the URL of the Socrata server. This property is observable.
* @type {String}
*/
this.url = '';
/**
* Gets or sets the filter query to pass to Socrata when querying the available data sources and their groups. Each string in the
* array is passed to Socrata as an independent search string and the results are concatenated to create the complete list.
* @type {String[]}
*/
this.filterQuery = ['limitTo=MAPS'];
/**
* Gets or sets a description of the custodian of the data sources in this group.
* This property is an HTML string that must be sanitized before display to the user.
* This property is observable.
* @type {String}
*/
this.dataCustodian = undefined;
/**
* Gets or sets a value indicating how datasets should be grouped. Valid values are:
* * `none` - Datasets are put in a flat list; they are not grouped at all.
* * `category` - Datasets are grouped according to their category in Socrata.
* @type {String}
*/
this.groupBy = 'category';
knockout.track(this, ['url', 'filterQuery', 'dataCustodian','category']);
};
inherit(CatalogGroup, SocrataCatalogGroup);
defineProperties(SocrataCatalogGroup.prototype, {
/**
* Gets the type of data member represented by this instance.
* @memberOf SocrataCatalogGroup.prototype
* @type {String}
*/
type : {
get : function() {
return 'socrata';
}
},
/**
* Gets a human-readable name for this type of data source, such as 'Web Map Service (WMS)'.
* @memberOf SocrataCatalogGroup.prototype
* @type {String}
*/
typeName : {
get : function() {
return 'Socrata Server';
}
},
/**
* Gets the set of functions used to update individual properties in {@link CatalogMember#updateFromJson}.
* When a property name in the returned object literal matches the name of a property on this instance, the value
* will be called as a function and passed a reference to this instance, a reference to the source JSON object
* literal, and the name of the property.
* @memberOf SocrataCatalogGroup.prototype
* @type {Object}
*/
updaters : {
get : function() {
return SocrataCatalogGroup.defaultUpdaters;
}
},
/**
* Gets the set of functions used to serialize individual properties in {@link CatalogMember#serializeToJson}.
* When a property name on the model matches the name of a property in the serializers object literal,
* the value will be called as a function and passed a reference to the model, a reference to the destination
* JSON object literal, and the name of the property.
* @memberOf SocrataCatalogGroup.prototype
* @type {Object}
*/
serializers : {
get : function() {
return SocrataCatalogGroup.defaultSerializers;
}
}
});
/**
* Gets or sets the set of default updater functions to use in {@link CatalogMember#updateFromJson}. Types derived from this type
* should expose this instance - cloned and modified if necesary - through their {@link CatalogMember#updaters} property.
* @type {Object}
*/
SocrataCatalogGroup.defaultUpdaters = clone(CatalogGroup.defaultUpdaters);
freezeObject(SocrataCatalogGroup.defaultUpdaters);
/**
* Gets or sets the set of default serializer functions to use in {@link CatalogMember#serializeToJson}. Types derived from this type
* should expose this instance - cloned and modified if necesary - through their {@link CatalogMember#serializers} property.
* @type {Object}
*/
SocrataCatalogGroup.defaultSerializers = clone(CatalogGroup.defaultSerializers);
SocrataCatalogGroup.defaultSerializers.items = CatalogGroup.enabledShareableItemsSerializer;
SocrataCatalogGroup.defaultSerializers.isLoading = function(socrataGroup, json, propertyName, options) {};
SocrataCatalogGroup.prototype._getValuesThatInfluenceLoad = function() {
return [this.url, this.filterQuery, this.groupBy, this.dataCustodian];
};
SocrataCatalogGroup.prototype._load = function() {
if (!defined(this.url) || this.url.length === 0) {
return undefined;
}
var that = this;
var promises = [];
for (var i = 0; i < this.filterQuery.length; i++) {
// Socrata always has CORS enabled, but we may proxy anyway in IE9 or if we want to cache.
var url = proxyCatalogItemUrl(that, this.url + '/api/search/views?' + this.filterQuery[i], '1d');
var promise = loadJson(url);
promises.push(promise);
}
return when.all(promises).then( function(queryResults) {
if (!defined(queryResults)) {
return;
}
var allResults = queryResults[0];
for (var p = 1; p < queryResults.length; p++) {
allResults.result.results = allResults.result.results.concat(queryResults[p].result.results);
}
populateGroupFromResults(that, allResults);
}).otherwise(function(e) {
throw new TerriaError({
sender: that,
title: that.name,
message: '\
Couldn\'t retrieve packages from this Socrata server.<br/><br/>\
If you entered the URL manually, please double-check it.<br/><br/>\
Otherwise, if reloading doesn\'t fix it, please report the problem by sending an email to <a href="mailto:'+that.terria.supportEmail+'">'+that.terria.supportEmail+'</a> with the technical details below. Thank you!<br/><br/>\
<pre>' + formatError(e) + '</pre>'
});
});
};
function populateGroupFromResults(socrataGroup, json) {
var items = json.results;
for (var itemIndex = 0; itemIndex < items.length; ++itemIndex) {
var item = items[itemIndex].view;
var geo = item.metadata.geo;
// Currently we only support spatial layers, which are identified by a geo {} object. TODO support other kinds of layers?
if (!geo || !defined(item.childViews)) { // items without a 'childViews' seem to be themselves child views
continue;
}
var id = item.category ?
socrataGroup.uniqueId + '/' + item.category + '/' + item.id :
socrataGroup.uniqueId + '/' + item.id;
var newItem = socrataGroup.terria.catalog.shareKeyIndex[id];
var alreadyExists = defined(newItem);
if (!alreadyExists) {
// Socrata is currently transitioning from a Geoserver/OWS tiling system to a "new backend" with GeoJSON download but no
// reliable public tiling endpoint.
if (item.newBackend) {
newItem = new GeoJsonCatalogItem(socrataGroup.terria);
// We have to choose a number of features to truncate to. We can go as high as 50,000 but in the case of Melbourne's
// urban forest canopies dataset, the file becomes 71MB.
newItem.url = socrataGroup.url + '/resource/' + item.childViews[0] + '.geojson' + '?$limit=10000';
} else {
newItem = new WebMapServiceCatalogItem(socrataGroup.terria);
newItem.url = socrataGroup.url + geo.owsUrl;
newItem.layers = geo.layers;
if (geo.namespace) {
// Socrata gives us a list of layers like 'geo_foo,geo_bar', but we need to prepend them with the WMS namespace.
newItem.layers = geo.namespace + ':' + newItem.layers.replace(/,/g, ',' + geo.namespace + ':');
}
if (geo.bboxCrs === 'EPSG:4326' && defined(geo.bbox)) {
var parts = geo.bbox.split(',');
if (parts.length === 4) {
newItem.rectangle = Rectangle.fromDegrees(parts[0], parts[1], parts[2], parts[3]);
}
}
}
}
newItem.name = item.name;
newItem.id = id;
if (defined(item.description)) {
newItem.info.push({
name: 'Description',
content: item.description
});
}
if (defined(item.license) && defined(item.license.name)) {
newItem.info.push({
name:'Licence',
content:
(item.license.logoUrl ? '<img src=' + socrataGroup.url + '/' + item.license.logoUrl + ' /> ' : '') +
(item.license.termsLink ? '<a href="' + item.license.termsLink + '">' + item.license.name + '</a>' : item.license.name)
});
}
if (item.columns.length > 0) {
newItem.info.push({
name: 'Attributes',
content: item.columns.map(function(e) { return e.name; }).join()
});
}
if (defined(item.tags) && item.tags.length > 0) {
newItem.info.push({
name: 'Tags',
content: item.tags.join()
});
}
newItem.dataUrlType = 'direct'; // should really be landingpage or something
newItem.dataUrl = socrataGroup.url + '/resource/' + item.id;
if (defined(socrataGroup.dataCustodian)) {
newItem.dataCustodian = socrataGroup.dataCustodian;
} else {
newItem.dataCustodian = item.attribution; // not quite right
}
if (socrataGroup.groupBy === 'category' && defined(item.category)) {
var existingGroup = socrataGroup.findFirstItemByName(item.category);
if (!defined(existingGroup)) {
existingGroup = new CatalogGroup(socrataGroup.terria);
existingGroup.name = item.category;
existingGroup.id = item.category;
socrataGroup.add(existingGroup);
}
existingGroup.add(newItem);
} else {
socrataGroup.add(newItem);
}
}
}
module.exports = SocrataCatalogGroup;