Files
openlayers/src/ol/featureloader.js
2015-10-28 10:29:04 +01:00

176 lines
6.3 KiB
JavaScript

goog.provide('ol.FeatureLoader');
goog.provide('ol.FeatureUrlFunction');
goog.provide('ol.featureloader');
goog.require('goog.asserts');
goog.require('goog.events');
goog.require('goog.net.EventType');
goog.require('goog.net.XhrIo');
goog.require('goog.net.XhrIo.ResponseType');
goog.require('ol.TileState');
goog.require('ol.format.FormatType');
goog.require('ol.xml');
/**
* {@link ol.source.Vector} sources use a function of this type to load
* features.
*
* This function takes an {@link ol.Extent} representing the area to be loaded,
* a `{number}` representing the resolution (map units per pixel) and an
* {@link ol.proj.Projection} for the projection as arguments. `this` within
* the function is bound to the {@link ol.source.Vector} it's called from.
*
* The function is responsible for loading the features and adding them to the
* source.
* @api
* @typedef {function(this:ol.source.Vector, ol.Extent, number,
* ol.proj.Projection)}
*/
ol.FeatureLoader;
/**
* {@link ol.source.Vector} sources use a function of this type to get the url
* to load features from.
*
* This function takes an {@link ol.Extent} representing the area to be loaded,
* a `{number}` representing the resolution (map units per pixel) and an
* {@link ol.proj.Projection} for the projection as arguments and returns a
* `{string}` representing the URL.
* @api
* @typedef {function(ol.Extent, number, ol.proj.Projection) : string}
*/
ol.FeatureUrlFunction;
/**
* @param {string|ol.FeatureUrlFunction} url Feature URL service.
* @param {ol.format.Feature} format Feature format.
* @param {function(this:ol.VectorTile, Array.<ol.Feature>, ol.proj.Projection)|function(this:ol.source.Vector, Array.<ol.Feature>)} success
* Function called with the loaded features and optionally with the data
* projection. Called with the vector tile or source as `this`.
* @param {function(this:ol.VectorTile)|function(this:ol.source.Vector)} failure
* Function called when loading failed. Called with the vector tile or
* source as `this`.
* @return {ol.FeatureLoader} The feature loader.
*/
ol.featureloader.loadFeaturesXhr = function(url, format, success, failure) {
return (
/**
* @param {ol.Extent} extent Extent.
* @param {number} resolution Resolution.
* @param {ol.proj.Projection} projection Projection.
* @this {ol.source.Vector|ol.VectorTile}
*/
function(extent, resolution, projection) {
var xhrIo = new goog.net.XhrIo();
xhrIo.setResponseType(
format.getType() == ol.format.FormatType.ARRAY_BUFFER ?
goog.net.XhrIo.ResponseType.ARRAY_BUFFER :
goog.net.XhrIo.ResponseType.TEXT);
goog.events.listen(xhrIo, goog.net.EventType.COMPLETE,
/**
* @param {Event} event Event.
* @private
* @this {ol.source.Vector}
*/
function(event) {
var xhrIo = event.target;
goog.asserts.assertInstanceof(xhrIo, goog.net.XhrIo,
'event.target/xhrIo is an instance of goog.net.XhrIo');
if (xhrIo.isSuccess()) {
var type = format.getType();
/** @type {Document|Node|Object|string|undefined} */
var source;
if (type == ol.format.FormatType.JSON) {
source = xhrIo.getResponseText();
} else if (type == ol.format.FormatType.TEXT) {
source = xhrIo.getResponseText();
} else if (type == ol.format.FormatType.XML) {
if (!goog.userAgent.IE) {
source = xhrIo.getResponseXml();
}
if (!source) {
source = ol.xml.parse(xhrIo.getResponseText());
}
} else if (type == ol.format.FormatType.ARRAY_BUFFER) {
source = xhrIo.getResponse();
} else {
goog.asserts.fail('unexpected format type');
}
if (source) {
var features = format.readFeatures(source,
{featureProjection: projection});
if (ol.ENABLE_VECTOR_TILE && success.length == 2) {
success.call(this, features, format.readProjection(source));
} else {
success.call(this, features);
}
} else {
goog.asserts.fail('undefined or null source');
}
} else {
failure.call(this);
}
goog.dispose(xhrIo);
}, false, this);
if (goog.isFunction(url)) {
xhrIo.send(url(extent, resolution, projection));
} else {
xhrIo.send(url);
}
});
};
/**
* Create an XHR feature loader for a `url` and `format`. The feature loader
* loads features (with XHR), parses the features, and adds them to the
* vector tile.
* @param {string|ol.FeatureUrlFunction} url Feature URL service.
* @param {ol.format.Feature} format Feature format.
* @return {ol.FeatureLoader} The feature loader.
* @api
*/
ol.featureloader.tile = function(url, format) {
return ol.featureloader.loadFeaturesXhr(url, format,
/**
* @param {Array.<ol.Feature>} features The loaded features.
* @param {ol.proj.Projection} projection Data projection.
* @this {ol.VectorTile}
*/
function(features, projection) {
this.setProjection(projection);
this.setFeatures(features);
},
/**
* @this {ol.VectorTile}
*/
function() {
this.setState(ol.TileState.ERROR);
});
};
/**
* Create an XHR feature loader for a `url` and `format`. The feature loader
* loads features (with XHR), parses the features, and adds them to the
* vector source.
* @param {string|ol.FeatureUrlFunction} url Feature URL service.
* @param {ol.format.Feature} format Feature format.
* @return {ol.FeatureLoader} The feature loader.
* @api
*/
ol.featureloader.xhr = function(url, format) {
return ol.featureloader.loadFeaturesXhr(url, format,
/**
* @param {Array.<ol.Feature>} features The loaded features.
* @this {ol.source.Vector}
*/
function(features) {
this.addFeatures(features);
}, /* FIXME handle error */ ol.nullFunction);
};