Stateless GetFeatureInfo for ol.source.ImageWMS

src/ol/source/imagewmssource.js

@@ -87,18 +87,6 @@ ol.source.ImageWMS = function(opt_options) {
    */
   this.imageSize_ = [0, 0];
 
-  /**
-   * @private
-   * @type {ol.proj.Projection}
-   */
-  this.renderedProjection_ = null;
-
-  /**
-   * @private
-   * @type {number}
-   */
-  this.renderedResolution_ = NaN;
-
   /**
    * @private
    * @type {number}
@@ -115,6 +103,14 @@ ol.source.ImageWMS = function(opt_options) {
 goog.inherits(ol.source.ImageWMS, ol.source.Image);
 
 
+/**
+ * @const
+ * @type {ol.Size}
+ * @private
+ */
+ol.source.ImageWMS.GETFEATUREINFO_IMAGE_SIZE_ = [101, 101];
+
+
 /**
  * Return the GetFeatureInfo URL for the passed coordinate, resolution, and
  * projection. Return `undefined` if the GetFeatureInfo URL cannot be
@@ -134,22 +130,13 @@ ol.source.ImageWMS.prototype.getGetFeatureInfoUrl =
 
   goog.asserts.assert(!('VERSION' in params));
 
-  if (!goog.isDef(this.url_) || goog.isNull(this.image_)) {
+  if (!goog.isDef(this.url_)) {
     return undefined;
   }
 
-  goog.asserts.assert(this.imageSize_[0] !== 0 &&
+  var extent = ol.extent.getForViewAndSize(
-      this.imageSize_[1] !== 0);
+      coordinate, resolution, 0,
-  goog.asserts.assert(!isNaN(this.renderedResolution_));
+      ol.source.ImageWMS.GETFEATUREINFO_IMAGE_SIZE_);
-  goog.asserts.assert(!goog.isNull(this.renderedProjection_));
-
-  if (resolution != this.renderedResolution_ ||
-      !ol.proj.equivalent(projection, this.renderedProjection_)) {
-    return undefined;
-  }
-
-  var extent = this.image_.getExtent();
-  var pixelRatio = this.image_.getPixelRatio();
 
   var baseParams = {
     'SERVICE': 'WMS',
@@ -161,15 +148,14 @@ ol.source.ImageWMS.prototype.getGetFeatureInfoUrl =
   };
   goog.object.extend(baseParams, this.params_, params);
 
-  var imageResolution = resolution / pixelRatio;
+  var x = Math.floor((coordinate[0] - extent[0]) / resolution);
-
+  var y = Math.floor((extent[3] - coordinate[1]) / resolution);
-  var x = Math.floor((coordinate[0] - extent[0]) / imageResolution);
-  var y = Math.floor((extent[3] - coordinate[1]) / imageResolution);
   goog.object.set(baseParams, this.v13_ ? 'I' : 'X', x);
   goog.object.set(baseParams, this.v13_ ? 'J' : 'Y', y);
 
-  return this.getRequestUrl_(extent, this.imageSize_, pixelRatio, projection,
+  return this.getRequestUrl_(
-      baseParams);
+      extent, ol.source.ImageWMS.GETFEATUREINFO_IMAGE_SIZE_,
+      1, projection, baseParams);
 };
 
 
@@ -251,8 +237,6 @@ ol.source.ImageWMS.prototype.getImage =
   this.image_ = new ol.Image(extent, resolution, pixelRatio,
       this.getAttributions(), url, this.crossOrigin_);
 
-  this.renderedProjection_ = projection;
-  this.renderedResolution_ = resolution;
   this.renderedRevision_ = this.getRevision();
 
   return this.image_;

test/spec/ol/source/imagewmssource.test.js

@@ -140,7 +140,6 @@ describe('ol.source.ImageWMS', function() {
 
     it('returns the expected GetFeatureInfo URL', function() {
       var source = new ol.source.ImageWMS(options);
-      source.getImage(extent, resolution, pixelRatio, projection);
       var url = source.getGetFeatureInfoUrl(
           [20, 30], resolution, projection,
           {INFO_FORMAT: 'text/plain'});
@@ -149,12 +148,12 @@ describe('ol.source.ImageWMS', function() {
       expect(uri.getDomain()).to.be('example.com');
       expect(uri.getPath()).to.be('/wms');
       var queryData = uri.getQueryData();
-      expect(queryData.get('BBOX')).to.be('20,10,40,30');
+      expect(queryData.get('BBOX')).to.be('24.95,14.95,35.05,25.05');
       expect(queryData.get('CRS')).to.be('EPSG:4326');
       expect(queryData.get('FORMAT')).to.be('image/png');
-      expect(queryData.get('HEIGHT')).to.be('200');
+      expect(queryData.get('HEIGHT')).to.be('101');
-      expect(queryData.get('I')).to.be('100');
+      expect(queryData.get('I')).to.be('50');
-      expect(queryData.get('J')).to.be('100');
+      expect(queryData.get('J')).to.be('50');
       expect(queryData.get('LAYERS')).to.be('layer');
       expect(queryData.get('QUERY_LAYERS')).to.be('layer');
       expect(queryData.get('REQUEST')).to.be('GetFeatureInfo');
@@ -163,13 +162,12 @@ describe('ol.source.ImageWMS', function() {
       expect(queryData.get('STYLES')).to.be('');
       expect(queryData.get('TRANSPARENT')).to.be('true');
       expect(queryData.get('VERSION')).to.be('1.3.0');
-      expect(queryData.get('WIDTH')).to.be('200');
+      expect(queryData.get('WIDTH')).to.be('101');
       expect(uri.getFragment()).to.be.empty();
     });
 
     it('sets the QUERY_LAYERS param as expected', function() {
       var source = new ol.source.ImageWMS(options);
-      source.getImage(extent, resolution, pixelRatio, projection);
       var url = source.getGetFeatureInfoUrl(
           [20, 30], resolution, projection,
           {INFO_FORMAT: 'text/plain', QUERY_LAYERS: 'foo,bar'});
@@ -178,12 +176,12 @@ describe('ol.source.ImageWMS', function() {
       expect(uri.getDomain()).to.be('example.com');
       expect(uri.getPath()).to.be('/wms');
       var queryData = uri.getQueryData();
-      expect(queryData.get('BBOX')).to.be('20,10,40,30');
+      expect(queryData.get('BBOX')).to.be('24.95,14.95,35.05,25.05');
       expect(queryData.get('CRS')).to.be('EPSG:4326');
       expect(queryData.get('FORMAT')).to.be('image/png');
-      expect(queryData.get('HEIGHT')).to.be('200');
+      expect(queryData.get('HEIGHT')).to.be('101');
-      expect(queryData.get('I')).to.be('100');
+      expect(queryData.get('I')).to.be('50');
-      expect(queryData.get('J')).to.be('100');
+      expect(queryData.get('J')).to.be('50');
       expect(queryData.get('LAYERS')).to.be('layer');
       expect(queryData.get('QUERY_LAYERS')).to.be('foo,bar');
       expect(queryData.get('REQUEST')).to.be('GetFeatureInfo');
@@ -192,7 +190,7 @@ describe('ol.source.ImageWMS', function() {
       expect(queryData.get('STYLES')).to.be('');
       expect(queryData.get('TRANSPARENT')).to.be('true');
       expect(queryData.get('VERSION')).to.be('1.3.0');
-      expect(queryData.get('WIDTH')).to.be('200');
+      expect(queryData.get('WIDTH')).to.be('101');
       expect(uri.getFragment()).to.be.empty();
     });
   });