/* Copyright (c) 2006-2010 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/Layer/Grid.js
* @requires OpenLayers/Tile/Image.js
*/
/**
* Class: OpenLayers.Layer.WMS
* Instances of OpenLayers.Layer.WMS are used to display data from OGC Web
* Mapping Services. Create a new WMS layer with the <OpenLayers.Layer.WMS>
* constructor.
*
* Inherits from:
* - <OpenLayers.Layer.Grid>
*/
OpenLayers.Layer.WMS = OpenLayers.Class(OpenLayers.Layer.Grid, {
/**
* Constant: DEFAULT_PARAMS
* {Object} Hashtable of default parameter key/value pairs
*/
DEFAULT_PARAMS: { service: "WMS",
version: "1.1.1",
request: "GetMap",
styles: "",
exceptions: "application/vnd.ogc.se_inimage",
format: "image/jpeg"
},
/**
* Property: reproject
* *Deprecated*. See http://trac.openlayers.org/wiki/SphericalMercator
* for information on the replacement for this functionality.
* {Boolean} Try to reproject this layer if its coordinate reference system
* is different than that of the base layer. Default is true.
* Set this in the layer options. Should be set to false in
* most cases.
*/
reproject: false,
/**
* APIProperty: isBaseLayer
* {Boolean} Default is true for WMS layer
*/
isBaseLayer: true,
/**
* APIProperty: encodeBBOX
* {Boolean} Should the BBOX commas be encoded? The WMS spec says 'no',
* but some services want it that way. Default false.
*/
encodeBBOX: false,
/**
* APIProperty: noMagic
* {Boolean} If true, the image format will not be automagicaly switched
* from image/jpeg to image/png or image/gif when using
* TRANSPARENT=TRUE. Also isBaseLayer will not changed by the
* constructor. Default false.
*/
noMagic: false,
/**
* Property: yx
* {Object} Keys in this object are EPSG codes for which the axis order
* is to be reversed (yx instead of xy, LatLon instead of LonLat), with
* true as value. This is only relevant for WMS versions >= 1.3.0.
*/
yx: {'EPSG:4326': true},
/**
* Constructor: OpenLayers.Layer.WMS
* Create a new WMS layer object
*
* Example:
* (code)
* var wms = new OpenLayers.Layer.WMS("NASA Global Mosaic",
* "http://wms.jpl.nasa.gov/wms.cgi",
* {layers: "modis,global_mosaic"});
* (end)
*
* Parameters:
* name - {String} A name for the layer
* url - {String} Base url for the WMS
* (e.g. http://wms.jpl.nasa.gov/wms.cgi)
* params - {Object} An object with key/value pairs representing the
* GetMap query string parameters and parameter values.
* options - {Ojbect} Hashtable of extra options to tag onto the layer
*/
initialize: function(name, url, params, options) {
var newArguments = [];
//uppercase params
params = OpenLayers.Util.upperCaseObject(params);
if (parseFloat(params.VERSION) >= 1.3 && !params.EXCEPTIONS) {
params.EXCEPTIONS = "INIMAGE";
}
newArguments.push(name, url, params, options);
OpenLayers.Layer.Grid.prototype.initialize.apply(this, newArguments);
OpenLayers.Util.applyDefaults(
this.params,
OpenLayers.Util.upperCaseObject(this.DEFAULT_PARAMS)
);
//layer is transparent
if (!this.noMagic && this.params.TRANSPARENT &&
this.params.TRANSPARENT.toString().toLowerCase() == "true") {
// unless explicitly set in options, make layer an overlay
if ( (options == null) || (!options.isBaseLayer) ) {
this.isBaseLayer = false;
}
// jpegs can never be transparent, so intelligently switch the
// format, depending on teh browser's capabilities
if (this.params.FORMAT == "image/jpeg") {
this.params.FORMAT = OpenLayers.Util.alphaHack() ? "image/gif"
: "image/png";
}
}
},
/**
* Method: destroy
* Destroy this layer
*/
destroy: function() {
// for now, nothing special to do here.
OpenLayers.Layer.Grid.prototype.destroy.apply(this, arguments);
},
/**
* Method: clone
* Create a clone of this layer
*
* Returns:
* {<OpenLayers.Layer.WMS>} An exact clone of this layer
*/
clone: function (obj) {
if (obj == null) {
obj = new OpenLayers.Layer.WMS(this.name,
this.url,
this.params,
this.getOptions());
}
//get all additions from superclasses
obj = OpenLayers.Layer.Grid.prototype.clone.apply(this, [obj]);
// copy/set any non-init, non-simple values here
return obj;
},
/**
* APIMethod: reverseAxisOrder
* Returns true if the axis order is reversed for the WMS version and
* projection of the layer.
*
* Returns:
* {Boolean} true if the axis order is reversed, false otherwise.
*/
reverseAxisOrder: function() {
return (parseFloat(this.params.VERSION) >= 1.3 &&
!!this.yx[this.map.getProjectionObject().getCode()]);
},
/**
* Method: getURL
* Return a GetMap query string for this layer
*
* Parameters:
* bounds - {<OpenLayers.Bounds>} A bounds representing the bbox for the
* request.
*
* Returns:
* {String} A string with the layer's url and parameters and also the
* passed-in bounds and appropriate tile size specified as
* parameters.
*/
getURL: function (bounds) {
bounds = this.adjustBounds(bounds);
var imageSize = this.getImageSize();
var newParams = {};
// WMS 1.3 introduced axis order
var reverseAxisOrder = this.reverseAxisOrder();
newParams.BBOX = this.encodeBBOX ?
bounds.toBBOX(null, reverseAxisOrder) :
bounds.toArray(reverseAxisOrder);
newParams.WIDTH = imageSize.w;
newParams.HEIGHT = imageSize.h;
var requestString = this.getFullRequestString(newParams);
return requestString;
},
/**
* Method: addTile
* addTile creates a tile, initializes it, and adds it to the layer div.
*
* Parameters:
* bounds - {<OpenLayers.Bounds>}
* position - {<OpenLayers.Pixel>}
*
* Returns:
* {<OpenLayers.Tile.Image>} The added OpenLayers.Tile.Image
*/
addTile:function(bounds,position) {
return new OpenLayers.Tile.Image(this, position, bounds,
null, this.tileSize);
},
/**
* APIMethod: mergeNewParams
* Catch changeParams and uppercase the new params to be merged in
* before calling changeParams on the super class.
*
* Once params have been changed, the tiles will be reloaded with
* the new parameters.
*
* Parameters:
* newParams - {Object} Hashtable of new params to use
*/
mergeNewParams:function(newParams) {
var upperParams = OpenLayers.Util.upperCaseObject(newParams);
var newArguments = [upperParams];
return OpenLayers.Layer.Grid.prototype.mergeNewParams.apply(this,
newArguments);
},
/**
* APIMethod: getFullRequestString
* Combine the layer's url with its params and these newParams.
*
* Add the SRS parameter from projection -- this is probably
* more eloquently done via a setProjection() method, but this
* works for now and always.
*
* Parameters:
* newParams - {Object}
* altUrl - {String} Use this as the url instead of the layer's url
*
* Returns:
* {String}
*/
getFullRequestString:function(newParams, altUrl) {
var projectionCode = this.map.getProjection();
var value = (projectionCode == "none") ? null : projectionCode
if (parseFloat(this.params.VERSION) >= 1.3) {
this.params.CRS = value;
} else {
this.params.SRS = value;
}
return OpenLayers.Layer.Grid.prototype.getFullRequestString.apply(
this, arguments);
},
CLASS_NAME: "OpenLayers.Layer.WMS"
});