/* 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
*/
/**
* Class: OpenLayers.Layer.MapServer
* Instances of OpenLayers.Layer.MapServer are used to display
* data from a MapServer CGI instance.
*
* Inherits from:
* - <OpenLayers.Layer.Grid>
*/
OpenLayers.Layer.MapServer = OpenLayers.Class(OpenLayers.Layer.Grid, {
/**
* Constant: DEFAULT_PARAMS
* {Object} Hashtable of default parameter key/value pairs
*/
DEFAULT_PARAMS: {
mode: "map",
map_imagetype: "png"
},
/**
* Constructor: OpenLayers.Layer.MapServer
* Create a new MapServer layer object
*
* Parameters:
* name - {String} A name for the layer
* url - {String} Base url for the MapServer CGI
* (e.g. http://www2.dmsolutions.ca/cgi-bin/mapserv)
* 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 = [];
newArguments.push(name, url, params, options);
OpenLayers.Layer.Grid.prototype.initialize.apply(this, newArguments);
this.params = OpenLayers.Util.applyDefaults(
this.params, this.DEFAULT_PARAMS
);
// unless explicitly set in options, if the layer is transparent,
// it will be an overlay
if (options == null || options.isBaseLayer == null) {
this.isBaseLayer = ((this.params.transparent != "true") &&
(this.params.transparent != true));
}
},
/**
* Method: clone
* Create a clone of this layer
*
* Returns:
* {<OpenLayers.Layer.MapServer>} An exact clone of this layer
*/
clone: function (obj) {
if (obj == null) {
obj = new OpenLayers.Layer.MapServer(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;
},
/**
* Method: 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);
},
/**
* Method: getURL
* Return a 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);
// Make a list, so that getFullRequestString uses literal ","
var extent = [bounds.left, bounds. bottom, bounds.right, bounds.top];
var imageSize = this.getImageSize();
// make lists, so that literal ','s are used
var url = this.getFullRequestString(
{mapext: extent,
imgext: extent,
map_size: [imageSize.w, imageSize.h],
imgx: imageSize.w / 2,
imgy: imageSize.h / 2,
imgxy: [imageSize.w, imageSize.h]
});
return url;
},
/**
* Method: getFullRequestString
* combine the layer's url with its params and these newParams.
*
* Parameter:
* newParams - {Object} New parameters that should be added to the
* request string.
* altUrl - {String} (optional) Replace the URL in the full request
* string with the provided URL.
*
* Returns:
* {String} A string with the layer's url and parameters embedded in it.
*/
getFullRequestString:function(newParams, altUrl) {
// use layer's url unless altUrl passed in
var url = (altUrl == null) ? this.url : altUrl;
// create a new params hashtable with all the layer params and the
// new params together. then convert to string
var allParams = OpenLayers.Util.extend({}, this.params);
allParams = OpenLayers.Util.extend(allParams, newParams);
var paramsString = OpenLayers.Util.getParameterString(allParams);
// if url is not a string, it should be an array of strings,
// in which case we will deterministically select one of them in
// order to evenly distribute requests to different urls.
if (url instanceof Array) {
url = this.selectUrl(paramsString, url);
}
// ignore parameters that are already in the url search string
var urlParams = OpenLayers.Util.upperCaseObject(
OpenLayers.Util.getParameters(url));
for(var key in allParams) {
if(key.toUpperCase() in urlParams) {
delete allParams[key];
}
}
paramsString = OpenLayers.Util.getParameterString(allParams);
// requestString always starts with url
var requestString = url;
// MapServer needs '+' seperating things like bounds/height/width.
// Since typically this is URL encoded, we use a slight hack: we
// depend on the list-like functionality of getParameterString to
// leave ',' only in the case of list items (since otherwise it is
// encoded) then do a regular expression replace on the , characters
// to '+'
//
paramsString = paramsString.replace(/,/g, "+");
if (paramsString != "") {
var lastServerChar = url.charAt(url.length - 1);
if ((lastServerChar == "&") || (lastServerChar == "?")) {
requestString += paramsString;
} else {
if (url.indexOf('?') == -1) {
//serverPath has no ? -- add one
requestString += '?' + paramsString;
} else {
//serverPath contains ?, so must already have paramsString at the end
requestString += '&' + paramsString;
}
}
}
return requestString;
},
CLASS_NAME: "OpenLayers.Layer.MapServer"
});