[76] | 1 | /* Copyright (c) 2006-2010 by OpenLayers Contributors (see authors.txt for |
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| 2 | * full list of contributors). Published under the Clear BSD license. |
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| 3 | * See http://svn.openlayers.org/trunk/openlayers/license.txt for the |
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| 4 | * full text of the license. */ |
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| 5 | |
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| 6 | |
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| 7 | /** |
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| 8 | * @requires OpenLayers/Tile.js |
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| 9 | * @requires OpenLayers/Request/XMLHttpRequest.js |
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| 10 | */ |
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| 11 | |
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| 12 | /** |
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| 13 | * Class: OpenLayers.Tile.WFS |
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| 14 | * Instances of OpenLayers.Tile.WFS are used to manage the image tiles |
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| 15 | * used by various layers. Create a new image tile with the |
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| 16 | * <OpenLayers.Tile.WFS> constructor. |
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| 17 | * |
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| 18 | * Inherits from: |
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| 19 | * - <OpenLayers.Tile> |
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| 20 | */ |
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| 21 | OpenLayers.Tile.WFS = OpenLayers.Class(OpenLayers.Tile, { |
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| 22 | |
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| 23 | /** |
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| 24 | * Property: features |
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| 25 | * {Array(<OpenLayers.Feature>)} list of features in this tile |
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| 26 | */ |
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| 27 | features: null, |
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| 28 | |
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| 29 | /** |
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| 30 | * Property: url |
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| 31 | * {String} |
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| 32 | */ |
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| 33 | url: null, |
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| 34 | |
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| 35 | /** |
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| 36 | * Property: request |
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| 37 | * {<OpenLayers.Request.XMLHttpRequest>} |
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| 38 | */ |
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| 39 | request: null, |
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| 40 | |
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| 41 | /** TBD 3.0 - reorder the parameters to the init function to put URL |
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| 42 | * as last, so we can continue to call tile.initialize() |
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| 43 | * without changing the arguments. |
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| 44 | * |
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| 45 | * Constructor: OpenLayers.Tile.WFS |
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| 46 | * Constructor for a new <OpenLayers.Tile.WFS> instance. |
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| 47 | * |
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| 48 | * Parameters: |
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| 49 | * layer - {<OpenLayers.Layer>} layer that the tile will go in. |
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| 50 | * position - {<OpenLayers.Pixel>} |
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| 51 | * bounds - {<OpenLayers.Bounds>} |
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| 52 | * url - {<String>} |
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| 53 | * size - {<OpenLayers.Size>} |
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| 54 | */ |
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| 55 | initialize: function(layer, position, bounds, url, size) { |
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| 56 | OpenLayers.Tile.prototype.initialize.apply(this, arguments); |
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| 57 | this.url = url; |
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| 58 | this.features = []; |
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| 59 | }, |
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| 60 | |
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| 61 | /** |
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| 62 | * APIMethod: destroy |
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| 63 | * nullify references to prevent circular references and memory leaks |
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| 64 | */ |
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| 65 | destroy: function() { |
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| 66 | OpenLayers.Tile.prototype.destroy.apply(this, arguments); |
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| 67 | this.destroyAllFeatures(); |
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| 68 | this.features = null; |
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| 69 | this.url = null; |
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| 70 | if(this.request) { |
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| 71 | this.request.abort(); |
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| 72 | //this.request.destroy(); |
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| 73 | this.request = null; |
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| 74 | } |
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| 75 | }, |
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| 76 | |
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| 77 | /** |
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| 78 | * Method: clear |
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| 79 | * Clear the tile of any bounds/position-related data so that it can |
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| 80 | * be reused in a new location. |
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| 81 | */ |
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| 82 | clear: function() { |
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| 83 | this.destroyAllFeatures(); |
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| 84 | }, |
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| 85 | |
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| 86 | /** |
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| 87 | * Method: draw |
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| 88 | * Check that a tile should be drawn, and load features for it. |
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| 89 | */ |
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| 90 | draw:function() { |
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| 91 | if (OpenLayers.Tile.prototype.draw.apply(this, arguments)) { |
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| 92 | if (this.isLoading) { |
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| 93 | //if already loading, send 'reload' instead of 'loadstart'. |
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| 94 | this.events.triggerEvent("reload"); |
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| 95 | } else { |
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| 96 | this.isLoading = true; |
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| 97 | this.events.triggerEvent("loadstart"); |
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| 98 | } |
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| 99 | this.loadFeaturesForRegion(this.requestSuccess); |
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| 100 | } |
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| 101 | }, |
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| 102 | |
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| 103 | /** |
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| 104 | * Method: loadFeaturesForRegion |
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| 105 | * Abort any pending requests and issue another request for data. |
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| 106 | * |
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| 107 | * Input are function pointers for what to do on success and failure. |
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| 108 | * |
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| 109 | * Parameters: |
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| 110 | * success - {function} |
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| 111 | * failure - {function} |
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| 112 | */ |
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| 113 | loadFeaturesForRegion:function(success, failure) { |
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| 114 | if(this.request) { |
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| 115 | this.request.abort(); |
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| 116 | } |
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| 117 | this.request = OpenLayers.Request.GET({ |
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| 118 | url: this.url, |
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| 119 | success: success, |
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| 120 | failure: failure, |
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| 121 | scope: this |
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| 122 | }); |
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| 123 | }, |
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| 124 | |
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| 125 | /** |
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| 126 | * Method: requestSuccess |
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| 127 | * Called on return from request succcess. Adds results via |
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| 128 | * layer.addFeatures in vector mode, addResults otherwise. |
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| 129 | * |
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| 130 | * Parameters: |
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| 131 | * request - {<OpenLayers.Request.XMLHttpRequest>} |
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| 132 | */ |
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| 133 | requestSuccess:function(request) { |
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| 134 | if (this.features) { |
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| 135 | var doc = request.responseXML; |
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| 136 | if (!doc || !doc.documentElement) { |
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| 137 | doc = request.responseText; |
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| 138 | } |
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| 139 | if (this.layer.vectorMode) { |
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| 140 | this.layer.addFeatures(this.layer.formatObject.read(doc)); |
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| 141 | } else { |
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| 142 | var xml = new OpenLayers.Format.XML(); |
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| 143 | if (typeof doc == "string") { |
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| 144 | doc = xml.read(doc); |
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| 145 | } |
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| 146 | var resultFeatures = xml.getElementsByTagNameNS( |
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| 147 | doc, "http://www.opengis.net/gml", "featureMember" |
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| 148 | ); |
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| 149 | this.addResults(resultFeatures); |
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| 150 | } |
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| 151 | } |
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| 152 | if (this.events) { |
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| 153 | this.events.triggerEvent("loadend"); |
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| 154 | } |
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| 155 | |
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| 156 | //request produced with success, we can delete the request object. |
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| 157 | //this.request.destroy(); |
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| 158 | this.request = null; |
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| 159 | }, |
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| 160 | |
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| 161 | /** |
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| 162 | * Method: addResults |
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| 163 | * Construct new feature via layer featureClass constructor, and add to |
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| 164 | * this.features. |
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| 165 | * |
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| 166 | * Parameters: |
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| 167 | * results - {Object} |
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| 168 | */ |
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| 169 | addResults: function(results) { |
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| 170 | for (var i=0; i < results.length; i++) { |
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| 171 | var feature = new this.layer.featureClass(this.layer, |
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| 172 | results[i]); |
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| 173 | this.features.push(feature); |
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| 174 | } |
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| 175 | }, |
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| 176 | |
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| 177 | |
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| 178 | /** |
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| 179 | * Method: destroyAllFeatures |
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| 180 | * Iterate through and call destroy() on each feature, removing it from |
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| 181 | * the local array |
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| 182 | */ |
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| 183 | destroyAllFeatures: function() { |
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| 184 | while(this.features.length > 0) { |
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| 185 | var feature = this.features.shift(); |
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| 186 | feature.destroy(); |
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| 187 | } |
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| 188 | }, |
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| 189 | |
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| 190 | CLASS_NAME: "OpenLayers.Tile.WFS" |
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| 191 | } |
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| 192 | ); |
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