1
/* Copyright (c) 2006-2008 MetaCarta, Inc., published under the Clear BSD
2
* license. See http://svn.openlayers.org/trunk/openlayers/license.txt for the
3
* full text of the license. */
6
* @requires OpenLayers/Layer/Grid.js
10
* Class: OpenLayers.Layer.MapServer
11
* Instances of OpenLayers.Layer.MapServer are used to display
12
* data from a MapServer CGI instance.
15
* - <OpenLayers.Layer.Grid>
17
OpenLayers.Layer.MapServer = OpenLayers.Class(OpenLayers.Layer.Grid, {
20
* Constant: DEFAULT_PARAMS
21
* {Object} Hashtable of default parameter key/value pairs
29
* Constructor: OpenLayers.Layer.MapServer
30
* Create a new MapServer layer object
33
* name - {String} A name for the layer
34
* url - {String} Base url for the MapServer CGI
35
* (e.g. http://www2.dmsolutions.ca/cgi-bin/mapserv)
36
* params - {Object} An object with key/value pairs representing the
37
* GetMap query string parameters and parameter values.
38
* options - {Ojbect} Hashtable of extra options to tag onto the layer
40
initialize: function(name, url, params, options) {
41
var newArguments = [];
42
newArguments.push(name, url, params, options);
43
OpenLayers.Layer.Grid.prototype.initialize.apply(this, newArguments);
45
this.params = OpenLayers.Util.applyDefaults(
46
this.params, this.DEFAULT_PARAMS
49
// unless explicitly set in options, if the layer is transparent,
50
// it will be an overlay
51
if (options == null || options.isBaseLayer == null) {
52
this.isBaseLayer = ((this.params.transparent != "true") &&
53
(this.params.transparent != true));
59
* Create a clone of this layer
62
* {<OpenLayers.Layer.MapServer>} An exact clone of this layer
64
clone: function (obj) {
66
obj = new OpenLayers.Layer.MapServer(this.name,
71
//get all additions from superclasses
72
obj = OpenLayers.Layer.Grid.prototype.clone.apply(this, [obj]);
74
// copy/set any non-init, non-simple values here
81
* Creates a tile, initializes it, and adds it to the layer div.
84
* bounds - {<OpenLayers.Bounds>}
85
* position - {<OpenLayers.Pixel>}
88
* {<OpenLayers.Tile.Image>} The added OpenLayers.Tile.Image
90
addTile:function(bounds,position) {
91
return new OpenLayers.Tile.Image(this, position, bounds,
97
* Return a query string for this layer
100
* bounds - {<OpenLayers.Bounds>} A bounds representing the bbox
104
* {String} A string with the layer's url and parameters and also
105
* the passed-in bounds and appropriate tile size specified
108
getURL: function (bounds) {
109
bounds = this.adjustBounds(bounds);
110
// Make a list, so that getFullRequestString uses literal ","
111
var extent = [bounds.left, bounds. bottom, bounds.right, bounds.top];
113
var imageSize = this.getImageSize();
115
// make lists, so that literal ','s are used
116
var url = this.getFullRequestString(
119
map_size: [imageSize.w, imageSize.h],
120
imgx: imageSize.w / 2,
121
imgy: imageSize.h / 2,
122
imgxy: [imageSize.w, imageSize.h]
129
* Method: getFullRequestString
130
* combine the layer's url with its params and these newParams.
133
* newParams - {Object} New parameters that should be added to the
135
* altUrl - {String} (optional) Replace the URL in the full request
136
* string with the provided URL.
139
* {String} A string with the layer's url and parameters embedded in it.
141
getFullRequestString:function(newParams, altUrl) {
142
// use layer's url unless altUrl passed in
143
var url = (altUrl == null) ? this.url : altUrl;
145
// create a new params hashtable with all the layer params and the
146
// new params together. then convert to string
147
var allParams = OpenLayers.Util.extend({}, this.params);
148
allParams = OpenLayers.Util.extend(allParams, newParams);
149
var paramsString = OpenLayers.Util.getParameterString(allParams);
151
// if url is not a string, it should be an array of strings,
152
// in which case we will deterministically select one of them in
153
// order to evenly distribute requests to different urls.
154
if (url instanceof Array) {
155
url = this.selectUrl(paramsString, url);
158
// ignore parameters that are already in the url search string
159
var urlParams = OpenLayers.Util.upperCaseObject(
160
OpenLayers.Util.getParameters(url));
161
for(var key in allParams) {
162
if(key.toUpperCase() in urlParams) {
163
delete allParams[key];
166
paramsString = OpenLayers.Util.getParameterString(allParams);
168
// requestString always starts with url
169
var requestString = url;
171
// MapServer needs '+' seperating things like bounds/height/width.
172
// Since typically this is URL encoded, we use a slight hack: we
173
// depend on the list-like functionality of getParameterString to
174
// leave ',' only in the case of list items (since otherwise it is
175
// encoded) then do a regular expression replace on the , characters
178
paramsString = paramsString.replace(/,/g, "+");
180
if (paramsString != "") {
181
var lastServerChar = url.charAt(url.length - 1);
182
if ((lastServerChar == "&") || (lastServerChar == "?")) {
183
requestString += paramsString;
185
if (url.indexOf('?') == -1) {
186
//serverPath has no ? -- add one
187
requestString += '?' + paramsString;
189
//serverPath contains ?, so must already have paramsString at the end
190
requestString += '&' + paramsString;
194
return requestString;
197
CLASS_NAME: "OpenLayers.Layer.MapServer"