Merge pull request #885 from ahocevar/wms-getfeatureinfo

Implement WMS GetFeatureInfo

src/ol/source/featureinfosource.js

@@ -0,0 +1,18 @@
+goog.provide('ol.source.FeatureInfoSource');
+
+
+
+/**
+ * @interface
+ */
+ol.source.FeatureInfoSource = function() {};
+
+
+/**
+ * @param {ol.Pixel} pixel Pixel.
+ * @param {ol.Map} map The map that the pixel belongs to.
+ * @param {function(string)} success Callback with feature info.
+ * @param {function()=} opt_error Optional error callback.
+ */
+ol.source.FeatureInfoSource.prototype.getFeatureInfoForPixel =
+    goog.abstractMethod;

src/ol/source/singleimagewmssource.js

@@ -1,8 +1,10 @@
 goog.provide('ol.source.SingleImageWMS');
 
+goog.require('goog.asserts');
 goog.require('ol.Image');
 goog.require('ol.ImageUrlFunction');
 goog.require('ol.extent');
+goog.require('ol.source.FeatureInfoSource');
 goog.require('ol.source.ImageSource');
 goog.require('ol.source.wms');
 
@@ -11,6 +13,7 @@ goog.require('ol.source.wms');
 /**
  * @constructor
  * @extends {ol.source.ImageSource}
+ * @implements {ol.source.FeatureInfoSource}
  * @param {ol.source.SingleImageWMSOptions} options Options.
  */
 ol.source.SingleImageWMS = function(options) {
@@ -28,6 +31,13 @@ ol.source.SingleImageWMS = function(options) {
     imageUrlFunction: imageUrlFunction
   });
 
+  /**
+   * @private
+   * @type {ol.source.WMSGetFeatureInfoOptions}
+   */
+  this.getFeatureInfoOptions_ = goog.isDef(options.getFeatureInfoOptions) ?
+      options.getFeatureInfoOptions : {};
+
   /**
    * @private
    * @type {ol.Image}
@@ -68,3 +78,22 @@ ol.source.SingleImageWMS.prototype.getImage =
   this.image_ = this.createImage(extent, resolution, size, projection);
   return this.image_;
 };
+
+
+/**
+ * @inheritDoc
+ */
+ol.source.SingleImageWMS.prototype.getFeatureInfoForPixel =
+    function(pixel, map, success, opt_error) {
+  var view2D = map.getView().getView2D(),
+      projection = view2D.getProjection(),
+      size = map.getSize(),
+      bottomLeft = map.getCoordinateFromPixel([0, size[1]]),
+      topRight = map.getCoordinateFromPixel([size[0], 0]),
+      extent = [bottomLeft[0], topRight[0], bottomLeft[1], topRight[1]],
+      url = this.imageUrlFunction(extent, size, projection);
+  goog.asserts.assert(goog.isDef(url),
+      'ol.source.SingleImageWMS#imageUrlFunction does not return a url');
+  ol.source.wms.getFeatureInfo(url, pixel, this.getFeatureInfoOptions_, success,
+      opt_error);
+};

src/ol/source/tiledwmssource.js

@@ -3,10 +3,12 @@
 goog.provide('ol.source.TiledWMS');
 
 goog.require('goog.array');
+goog.require('goog.asserts');
 goog.require('goog.math');
 goog.require('ol.TileCoord');
 goog.require('ol.TileUrlFunction');
 goog.require('ol.extent');
+goog.require('ol.source.FeatureInfoSource');
 goog.require('ol.source.ImageTileSource');
 goog.require('ol.source.wms');
 
@@ -15,9 +17,11 @@ goog.require('ol.source.wms');
 /**
  * @constructor
  * @extends {ol.source.ImageTileSource}
+ * @implements {ol.source.FeatureInfoSource}
  * @param {ol.source.TiledWMSOptions} options Tiled WMS options.
  */
 ol.source.TiledWMS = function(options) {
+
   var tileGrid;
   if (goog.isDef(options.tileGrid)) {
     tileGrid = options.tileGrid;
@@ -28,6 +32,7 @@ ol.source.TiledWMS = function(options) {
   if (!goog.isDef(urls) && goog.isDef(options.url)) {
     urls = ol.TileUrlFunction.expandUrl(options.url);
   }
+
   if (goog.isDef(urls)) {
     var tileUrlFunctions = goog.array.map(
         urls, function(url) {
@@ -81,5 +86,35 @@ ol.source.TiledWMS = function(options) {
         tileCoordTransform, tileUrlFunction)
   });
 
+  /**
+   * @private
+   * @type {ol.source.WMSGetFeatureInfoOptions}
+   */
+  this.getFeatureInfoOptions_ = goog.isDef(options.getFeatureInfoOptions) ?
+      options.getFeatureInfoOptions : {};
+
 };
 goog.inherits(ol.source.TiledWMS, ol.source.ImageTileSource);
+
+
+/**
+ * @inheritDoc
+ */
+ol.source.TiledWMS.prototype.getFeatureInfoForPixel =
+    function(pixel, map, success, opt_error) {
+  var coord = map.getCoordinateFromPixel(pixel),
+      view2D = map.getView().getView2D(),
+      projection = view2D.getProjection(),
+      tileGrid = goog.isNull(this.tileGrid) ?
+          ol.tilegrid.getForProjection(projection) : this.tileGrid,
+      tileCoord = tileGrid.getTileCoordForCoordAndResolution(coord,
+          view2D.getResolution()),
+      tileExtent = tileGrid.getTileCoordExtent(tileCoord),
+      offset = map.getPixelFromCoordinate(ol.extent.getTopLeft(tileExtent)),
+      url = this.tileUrlFunction(tileCoord, projection);
+  goog.asserts.assert(goog.isDef(url),
+      'ol.source.TiledWMS#tileUrlFunction does not return a url');
+  ol.source.wms.getFeatureInfo(url,
+      [pixel[0] - offset[0], pixel[1] - offset[1]], this.getFeatureInfoOptions_,
+      success, opt_error);
+};

src/ol/source/wmssource.exports

@@ -0,0 +1 @@
+@exportSymbol ol.source.WMSGetFeatureInfoMethod

src/ol/source/wmssource.js

@@ -1,9 +1,29 @@
+goog.provide('ol.source.WMSGetFeatureInfoMethod');
 goog.provide('ol.source.wms');
 
+goog.require('goog.net.XhrIo');
 goog.require('goog.object');
 goog.require('goog.uri.utils');
 
 
+/**
+ * Method to use to get WMS feature info.
+ * @enum {string}
+ */
+ol.source.WMSGetFeatureInfoMethod = {
+  /**
+   * Load the info in an IFRAME. Only works with 'text/html and 'text/plain' as
+   * `INFO_FORMAT`.
+   */
+  IFRAME: 'iframe',
+  /**
+   * Use an asynchronous GET request. Requires CORS headers or a server at the
+   * same origin as the application script.
+   */
+  XHR_GET: 'xhr_get'
+};
+
+
 /**
  * @param {string} baseUrl WMS base url.
  * @param {Object.<string, string|number>} params Request parameters.
@@ -40,3 +60,60 @@ ol.source.wms.getUrl =
 
   return goog.uri.utils.appendParamsFromMap(baseUrl, baseParams);
 };
+
+
+/**
+ * @param {string} url URL as provided by the url function.
+ * @param {ol.Pixel} pixel Pixel.
+ * @param {Object} options Options as defined in the source.
+ * @param {function(string)} success Callback function for successful queries.
+ * @param {function()=} opt_error Optional callback function for unsuccessful
+ *     queries.
+ */
+ol.source.wms.getFeatureInfo =
+    function(url, pixel, options, success, opt_error) {
+  // TODO: This could be done in a smarter way if the url function was not a
+  // closure
+  url = url.replace('REQUEST=GetMap', 'REQUEST=GetFeatureInfo')
+      .replace(ol.source.wms.regExes.layers, 'LAYERS=$1&QUERY_LAYERS=$1');
+  options = goog.isDef(options) ? goog.object.clone(options) : {};
+  var localOptions = {
+    method: ol.source.WMSGetFeatureInfoMethod.IFRAME,
+    params: {}
+  };
+  goog.object.extend(localOptions, options);
+  var params = {'INFO_FORMAT': 'text/html'},
+      version = parseFloat(url.match(ol.source.wms.regExes.version)[1]),
+      x = Math.round(pixel[0]),
+      y = Math.round(pixel[1]);
+  if (version >= 1.3) {
+    goog.object.extend(params, {'I': x, 'J': y});
+  } else {
+    goog.object.extend(params, {'X': x, 'Y': y});
+  }
+  goog.object.extend(params, localOptions.params);
+  url = goog.uri.utils.appendParamsFromMap(url, params);
+  if (localOptions.method == ol.source.WMSGetFeatureInfoMethod.IFRAME) {
+    goog.global.setTimeout(function() {
+      success('<iframe seamless src="' + url + '"></iframe>');
+    }, 0);
+  } else if (localOptions.method == ol.source.WMSGetFeatureInfoMethod.XHR_GET) {
+    goog.net.XhrIo.send(url, function(event) {
+      var xhr = event.target;
+      if (xhr.isSuccess()) {
+        success(xhr.getResponseText());
+      } else if (goog.isDef(opt_error)) {
+        opt_error();
+      }
+    });
+  }
+};
+
+
+/**
+ * @enum {RegExp}
+ */
+ol.source.wms.regExes = {
+  layers: (/LAYERS=([^&]+)/),
+  version: (/VERSION=([^&]+)/)
+};