12fa9b54ef
Since loadstart is being fired here, it makes sense to fire loadend as well. The isLoading flag also needs to be cleared. Needs tests still.
150 lines
4.2 KiB
JavaScript
150 lines
4.2 KiB
JavaScript
/* Copyright (c) 2006-2012 by OpenLayers Contributors (see authors.txt for
|
|
* full list of contributors). Published under the Clear BSD license.
|
|
* See http://svn.openlayers.org/trunk/openlayers/license.txt for the
|
|
* full text of the license. */
|
|
|
|
|
|
/**
|
|
* @requires OpenLayers/Tile.js
|
|
* @requires OpenLayers/Format/JSON.js
|
|
*/
|
|
|
|
/**
|
|
* Class: OpenLayers.Tile.UTFGrid
|
|
* Instances of OpenLayers.Tile.UTFGrid are used to manage
|
|
* UTFGrids. This is an unusual tile type in that it doesn't have a
|
|
* rendered image; only a 'hit grid' that can be used to
|
|
* look up feature attributes.
|
|
*
|
|
* See the <OpenLayers.Tile.UTFGrid> constructor for details on constructing a
|
|
* new instance.
|
|
*
|
|
* Inherits from:
|
|
* - <OpenLayers.Tile>
|
|
*/
|
|
OpenLayers.Tile.UTFGrid = OpenLayers.Class(OpenLayers.Tile, {
|
|
|
|
/**
|
|
* Property: url
|
|
* {String}
|
|
* The URL of the UTFGrid file being requested. Provided by the <getURL>
|
|
* method.
|
|
*/
|
|
url: null,
|
|
|
|
/**
|
|
* Property: json
|
|
* {Object}
|
|
* Stores the parsed JSON tile data structure.
|
|
*/
|
|
json: null,
|
|
|
|
/**
|
|
* Property: format
|
|
* {OpenLayers.Format.JSON}
|
|
* Parser instance used to parse JSON for cross browser support. The native
|
|
* JSON.parse method will be used where available (all except IE<8).
|
|
*/
|
|
format: null,
|
|
|
|
/**
|
|
* Constructor: OpenLayers.Tile.UTFGrid
|
|
* Constructor for a new <OpenLayers.Tile.UTFGrid> instance.
|
|
*
|
|
* Parameters:
|
|
* layer - {<OpenLayers.Layer>} layer that the tile will go in.
|
|
* position - {<OpenLayers.Pixel>}
|
|
* bounds - {<OpenLayers.Bounds>}
|
|
* url - {<String>} Deprecated. Remove me in 3.0.
|
|
* size - {<OpenLayers.Size>}
|
|
* options - {Object}
|
|
*/
|
|
|
|
/**
|
|
* APIMethod: destroy
|
|
* nullify references to prevent circular references and memory leaks
|
|
*/
|
|
destroy: function() {
|
|
this.clear();
|
|
OpenLayers.Tile.prototype.destroy.apply(this, arguments);
|
|
},
|
|
|
|
/**
|
|
* Method: draw
|
|
* Check that a tile should be drawn, and draw it.
|
|
* In the case of UTFGrids, "drawing" it means fetching and
|
|
* parsing the json.
|
|
*
|
|
* Returns:
|
|
* {Boolean} Was a tile drawn?
|
|
*/
|
|
draw: function() {
|
|
var drawn = OpenLayers.Tile.prototype.draw.apply(this, arguments);
|
|
if (drawn) {
|
|
if (this.isLoading) {
|
|
//if we're already loading, send 'reload' instead of 'loadstart'.
|
|
this.events.triggerEvent("reload");
|
|
} else {
|
|
this.isLoading = true;
|
|
this.events.triggerEvent("loadstart");
|
|
}
|
|
this.url = this.layer.getURL(this.bounds);
|
|
|
|
if (this.layer.useJSONP) {
|
|
// Use JSONP method to avoid xbrowser policy
|
|
var ols = new OpenLayers.Protocol.Script({
|
|
url: this.url,
|
|
callback: function(response) {
|
|
this.isLoading = false;
|
|
this.events.triggerEvent("loadend");
|
|
this.json = response.data;
|
|
},
|
|
scope: this
|
|
});
|
|
ols.read();
|
|
} else {
|
|
// Use standard XHR
|
|
OpenLayers.Request.GET({
|
|
url: this.url,
|
|
callback: function(response) {
|
|
this.isLoading = false;
|
|
this.events.triggerEvent("loadend");
|
|
if (response.status === 200) {
|
|
this.parseData(response);
|
|
}
|
|
},
|
|
scope: this
|
|
});
|
|
}
|
|
} else {
|
|
this.unload();
|
|
}
|
|
return drawn;
|
|
},
|
|
|
|
/**
|
|
* Method: parseJSON
|
|
* Parse the JSON from a request
|
|
*
|
|
* Returns:
|
|
* {Object} parsed javascript data
|
|
*/
|
|
parseData: function(req) {
|
|
if (!this.format) {
|
|
this.format = new OpenLayers.Format.JSON();
|
|
}
|
|
this.json = this.format.read(req.responseText);
|
|
},
|
|
|
|
/**
|
|
* Method: clear
|
|
* Delete data stored with this tile.
|
|
*/
|
|
clear: function() {
|
|
this.json = null;
|
|
},
|
|
|
|
CLASS_NAME: "OpenLayers.Tile.UTFGrid"
|
|
|
|
});
|