Files
openlayers/lib/OpenLayers/Layer/GML.js
2007-09-11 23:31:44 +00:00

132 lines
3.9 KiB
JavaScript

/* Copyright (c) 2006-2007 MetaCarta, Inc., published under a modified BSD license.
* See http://svn.openlayers.org/trunk/openlayers/repository-license.txt
* for the full text of the license. */
/**
* @requires OpenLayers/Layer/Vector.js
* @requires OpenLayers/Ajax.js
*
* Class: OpenLayers.Layer.GML
* Create a vector layer by parsing a GML file. The GML file is
* passed in as a parameter.
*
* Inherits from:
* - <OpenLayers.Layer.Vector>
*/
OpenLayers.Layer.GML = OpenLayers.Class(OpenLayers.Layer.Vector, {
/**
* Property: loaded
* {Boolean} Flag for whether the GML data has been loaded yet.
*/
loaded: false,
/**
* APIProperty: format
* {<OpenLayers.Format>} The format you want the data to be parsed with.
*/
format: null,
/**
* Constructor: OpenLayers.Layer.GML
* Load and parse a single file on the web, according to the format
* provided via the 'format' option, defaulting to GML.
*
* Parameters:
* name - {String}
* url - {String} URL of a GML file.
* options - {Object} Hashtable of extra options to tag onto the layer.
*/
initialize: function(name, url, options) {
var newArguments = [];
newArguments.push(name, options);
OpenLayers.Layer.Vector.prototype.initialize.apply(this, newArguments);
this.url = url;
},
/**
* APIMethod: setVisibility
* Set the visibility flag for the layer and hide/show&redraw accordingly.
* Fire event unless otherwise specified
* GML will be loaded if the layer is being made visible for the first
* time.
*
* Parameters:
* visible - {Boolean} Whether or not to display the layer
* (if in range)
* noEvent - {Boolean}
*/
setVisibility: function(visibility, noEvent) {
OpenLayers.Layer.Vector.prototype.setVisibility.apply(this, arguments);
if(this.visibility && !this.loaded){
// Load the GML
this.loadGML();
}
},
/**
* Method: moveTo
* If layer is visible and GML has not been loaded, load GML, then load GML
* and call OpenLayers.Layer.Vector.moveTo() to redraw at the new location.
*
* Parameters:
* bounds - {Object}
* zoomChanged - {Object}
* minor - {Object}
*/
moveTo:function(bounds, zoomChanged, minor) {
OpenLayers.Layer.Vector.prototype.moveTo.apply(this, arguments);
// Wait until initialisation is complete before loading GML
// otherwise we can get a race condition where the root HTML DOM is
// loaded after the GML is paited.
// See http://trac.openlayers.org/ticket/404
if(this.visibility && !this.loaded){
this.loadGML();
}
},
/**
* Method: loadGML
*/
loadGML: function() {
if (!this.loaded) {
var results = OpenLayers.loadURL(this.url, null, this, this.requestSuccess, this.requestFailure);
this.loaded = true;
}
},
/**
* Method: requestSuccess
* Process GML after it has been loaded.
* Called by initialise() and loadUrl() after the GML has been loaded.
*
* Parameters:
* request - {String}
*/
requestSuccess:function(request) {
var doc = request.responseXML;
if (!doc || request.fileType!="XML") {
doc = request.responseText;
}
var gml = this.format ? new this.format() : new OpenLayers.Format.GML();
this.addFeatures(gml.read(doc));
},
/**
* Method: requestFailure
* Process a failed loading of GML.
* Called by initialise() and loadUrl() if there was a problem loading GML.
*
* Parameters:
* request - {String}
*/
requestFailure: function(request) {
alert("Error in loading GML file "+this.url);
},
CLASS_NAME: "OpenLayers.Layer.GML"
});