Merge pull request #364 from andygup/v2.9.5

V2.9.5

CHANGELOG.md

@@ -1,5 +1,13 @@
 # offline-editor-js - Changelog
 
+## Version 2.9.5 - July 14, 2015
+
+No breaking changes.
+
+**Enhancements**
+* In reference to #288, added tileLayer.showBlankTiles boolean property to both offlineTilesEnabler 
+and OfflineTilesEnablerLayer.
+
 ## Version 2.9.4.1 - July 10, 2015
 
 Minor doc update. Fixed broken link in README.

dist/offline-edit-src.js

@@ -1,4 +1,4 @@
-/*! offline-editor-js - v2.9.4 - 2015-07-10
+/*! offline-editor-js - v2.9.5 - 2015-07-14
 *   Copyright (c) 2015 Environmental Systems Research Institute, Inc.
 *   Apache License*/
 /*jshint -W030 */

dist/offline-tiles-advanced-src.js

@@ -1,4 +1,4 @@
-/*! offline-editor-js - v2.9.4 - 2015-07-10
+/*! offline-editor-js - v2.9.5 - 2015-07-14
 *   Copyright (c) 2015 Environmental Systems Research Institute, Inc.
 *   Apache License*/
 define([
@@ -51,6 +51,13 @@ define([
                 isOnline = state; console.log("STATE IS: " + state);
             }
 
+            /**
+             * Option to show/hide blank tile images. When using multiple basemap layers,
+             * if one has no tiles, this will display and cover another basemap storage which may have tiles.
+             * @type {boolean}
+             */
+            this.showBlankTiles = true;
+
             /**
              * IMPORTANT! proxyPath is set to null by default since we assume Feature Service is CORS-enabled.
              * All AGOL Feature Services are CORS-enabled.
@@ -138,7 +145,7 @@ define([
             /* temporary URL returned immediately, as we haven't retrieved the image from the indexeddb yet */
             var tileid = "void:/"+level+"/"+row+"/"+col;
             var img = null;
-            this._tilesCore._getTiles(img,this._imageType,url,tileid,this.offline.store,query);
+            this._tilesCore._getTiles(img,this._imageType,url,tileid,this.offline.store,query,this.showBlankTiles);
 
             return tileid;
         },
@@ -806,9 +813,11 @@ O.esri.Tiles.TilesCore = function(){
      * @param url the url of the tile
      * @param tileid a reference to the tile's unique level, row and column
      * @param store
+     * @param query Dojo Query
+     * @param showBlankTiles
      * @private
      */
-    this._getTiles = function(image,imageType,url,tileid,store,query){
+    this._getTiles = function(image,imageType,url,tileid,store,query,showBlankTiles){
         store.retrieve(url, function(success, offlineTile)
         { console.log("TILE RETURN " + success + ", " + offlineTile.url);
             /* when the .getTileUrl() callback is triggered we replace the temporary URL originally returned by the data:image url */
@@ -824,6 +833,10 @@ O.esri.Tiles.TilesCore = function(){
                 console.log("found tile offline", url);
                 imgURL = "data:image/" + imageType +";base64," + offlineTile.img;
             }
+            else if( !showBlankTiles ) {
+                console.log("showBlankTiles = false");
+                imgURL = "data:image/png;base64," + "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";
+            }
             else
             {
                 image.style.borderColor = "green";

dist/offline-tiles-basic-src.js

@@ -1,4 +1,4 @@
-/*! offline-editor-js - v2.9.4 - 2015-07-10
+/*! offline-editor-js - v2.9.5 - 2015-07-14
 *   Copyright (c) 2015 Environmental Systems Research Institute, Inc.
 *   Apache License*/
 define([
@@ -51,6 +51,13 @@ define([
                     isOnline = state; console.log("STATE IS: " + state);
                 }
 
+                /**
+                 * Option to show/hide blank tile images. When using multiple basemap layers,
+                 * if one has no tiles, this will display and cover another basemap storage which may have tiles.
+                 * @type {boolean}
+                 */
+                layer.showBlankTiles = true;
+
                 /**
                  * IMPORTANT! proxyPath is set to null by default since we assume Feature Service is CORS-enabled.
                  * All AGOL Feature Services are CORS-enabled.
@@ -106,7 +113,7 @@ define([
 
                                 var img = null;
 
-                                layer._tilesCore._getTiles(img,this._imageType,url,tileid,this.offline.store,query);
+                                layer._tilesCore._getTiles(img,this._imageType,url,tileid,this.offline.store,query,layer.showBlankTiles);
 
                                 return tileid;
                             };
@@ -722,9 +729,11 @@ O.esri.Tiles.TilesCore = function(){
      * @param url the url of the tile
      * @param tileid a reference to the tile's unique level, row and column
      * @param store
+     * @param query Dojo Query
+     * @param showBlankTiles
      * @private
      */
-    this._getTiles = function(image,imageType,url,tileid,store,query){
+    this._getTiles = function(image,imageType,url,tileid,store,query,showBlankTiles){
         store.retrieve(url, function(success, offlineTile)
         { console.log("TILE RETURN " + success + ", " + offlineTile.url);
             /* when the .getTileUrl() callback is triggered we replace the temporary URL originally returned by the data:image url */
@@ -740,6 +749,10 @@ O.esri.Tiles.TilesCore = function(){
                 console.log("found tile offline", url);
                 imgURL = "data:image/" + imageType +";base64," + offlineTile.img;
             }
+            else if( !showBlankTiles ) {
+                console.log("showBlankTiles = false");
+                imgURL = "data:image/png;base64," + "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";
+            }
             else
             {
                 image.style.borderColor = "green";

dist/offline-tpk-src.js

@@ -1,4 +1,4 @@
-/*! offline-editor-js - v2.9.4 - 2015-07-10
+/*! offline-editor-js - v2.9.5 - 2015-07-14
 *   Copyright (c) 2015 Environmental Systems Research Institute, Inc.
 *   Apache License*/
 /**

doc/offlinetilesenabler.md

@@ -14,9 +14,10 @@ Constructor | Description
 `O.esri.Tiles.OfflineTilesEnabler()` | Creates an instance of the offlineTilesEnabler class. This library allows you to extend an ArcGISTiledMapServiceLayer with partial offline capability as well as manage the online/offline resynchronization process.
 
 ###Properties
-Property  | Description
---- | ---
-`layer.offline.proxyPath`| The default is `null`. If you have a CORS-enabled service then use the default. Don't forget to check your proxy configuration to allow connections for all possible services that you might be using. More information on using proxies with ArcGIS can be found here: [https://developers.arcgis.com/javascript/jshelp/ags_proxy.html](https://developers.arcgis.com/javascript/jshelp/ags_proxy.html).
+Property  | Value | Description
+--- | --- | ---
+`layer.showBlankTiles`| `true` | By default the library will show a 256x256 grey PNG image that says "NO TILE". To override this behavior, especially if you are using multiple tile layers and you don't want the grey "NO TILE" image to interfere then set this property to `false`.
+`layer.offline.proxyPath`| `null` | The default is `null`. If you have a CORS-enabled service then use the default. Don't forget to check your proxy configuration to allow connections for all possible services that you might be using. More information on using proxies with ArcGIS can be found here: [https://developers.arcgis.com/javascript/jshelp/ags_proxy.html](https://developers.arcgis.com/javascript/jshelp/ags_proxy.html).
 
 ###Methods
 Methods | Returns | Description

doc/offlinetilesenablerlayer.md

@@ -14,9 +14,10 @@ Constructor | Description
 `O.esri.Tiles.OfflineTileEnablerLayer(url,callback,state)` | Creates an instance of the offlineTileEnabler class. This library allows you to extend an ArcGISTiledMapServiceLayer with offline capability as well as manage the online/offline resynchronization process. Any Esri basemap REST endpoint should work. The state property is a boolean for specifying if the application is intializing the layer online (true) or offline (false). When you first load the map you should set this property to `true`.
 
 ###Properties
-Property  | Description
---- | ---
-`layer.offline.proxyPath`| For CORS enabled servers this can be set to `null`. The default is null. All ArcGIS Online-based services uses CORS. If you are using a non-CORS enabled server you'll need a proxy. Don't forget to check your proxy configuration to allow connections for all possible services that you might be using. More information on using proxies with ArcGIS can be found here: [https://developers.arcgis.com/javascript/jshelp/ags_proxy.html](https://developers.arcgis.com/javascript/jshelp/ags_proxy.html).
+Property  | Value | Description
+--- | --- | ---
+`layer.showBlankTiles`| `true` | By default the library will show a 256x256 grey PNG image that says "NO TILE". To override this behavior, especially if you are using multiple tile layers and you don't want the grey "NO TILE" image to interfere then set this property to `false`.
+`layer.offline.proxyPath`| `null` | The default is `null`. If you have a CORS-enabled service then use the default. Don't forget to check your proxy configuration to allow connections for all possible services that you might be using. More information on using proxies with ArcGIS can be found here: [https://developers.arcgis.com/javascript/jshelp/ags_proxy.html](https://developers.arcgis.com/javascript/jshelp/ags_proxy.html).
 
 ###Methods
 Methods | Returns | Description

lib/tiles/OfflineTilesEnablerLayer.js

@@ -48,6 +48,13 @@ define([
                 isOnline = state; console.log("STATE IS: " + state);
             }
 
+            /**
+             * Option to show/hide blank tile images. When using multiple basemap layers,
+             * if one has no tiles, this will display and cover another basemap storage which may have tiles.
+             * @type {boolean}
+             */
+            this.showBlankTiles = true;
+
             /**
              * IMPORTANT! proxyPath is set to null by default since we assume Feature Service is CORS-enabled.
              * All AGOL Feature Services are CORS-enabled.
@@ -135,7 +142,7 @@ define([
             /* temporary URL returned immediately, as we haven't retrieved the image from the indexeddb yet */
             var tileid = "void:/"+level+"/"+row+"/"+col;
             var img = null;
-            this._tilesCore._getTiles(img,this._imageType,url,tileid,this.offline.store,query);
+            this._tilesCore._getTiles(img,this._imageType,url,tileid,this.offline.store,query,this.showBlankTiles);
 
             return tileid;
         },