Removed commands and added buttons in game options + fixed minor NPE

WebContent/game.jsp

@@ -481,6 +481,13 @@ boolean allowBlankCards = injector.getInstance(Key.get(new TypeLiteral<Boolean>(
         <span class="base_card_sets"></span>
         <span class="extra_card_sets"></span>
       </fieldset>
+      <fieldset>
+        <legend>Custom Card Sets</legend>
+        <input type="button" class="add_custom_deck_json" value="Upload JSON"/>
+        <input type="button" class="add_custom_deck_url" value="Download from URL"/>
+
+        <input id="file-input" type="file" accept="application/json" style="display: none;"/>
+      </fieldset>
       <% if (allowBlankCards) { %>
         <br/>
         <label id="blanks_limit_label" title="Blank cards allow a player to type in their own answer.">

WebContent/js/cah.app.js

@@ -213,22 +213,6 @@ function chatsubmit_click(game_id, parent_element) {
       case 'names':
         ajax = cah.Ajax.build(cah.$.AjaxOperation.NAMES);
         break;
-      case 'addcustomdeck_json':
-        if (game_id !== null) {
-          ajax = cah.Ajax.build(cah.$.AjaxOperation.ADD_CARDSET)
-              .withCustomDeckJson(text).withGameId(game_id);
-        } else {
-          cah.log.error("This command only works in a game.");
-        }
-        break;
-      case 'addcustomdeck_url':
-        if (game_id !== null) {
-          ajax = cah.Ajax.build(cah.$.AjaxOperation.ADD_CARDSET)
-              .withCustomDeckUrl(text).withGameId(game_id);
-        } else {
-          cah.log.error("This command only works in a game.");
-        }
-        break;
       case 'removecustomdeck':
         if (game_id !== null) {
           ajax = cah.Ajax.build(cah.$.AjaxOperation.REMOVE_CARDSET).withCustomDeckId(parseInt(text.split(' ')[0]))

WebContent/js/cah.game.js

@@ -305,6 +305,8 @@ cah.Game = function(id) {
   $(".confirm_card", this.element_).click(cah.bind(this, this.confirmClick_));
   $(".game_show_last_round", this.element_).click(cah.bind(this, this.showLastRoundClick_));
   $(".game_show_options", this.element_).click(cah.bind(this, this.showOptionsClick_));
+  $(".add_custom_deck_json", this.element_).click(cah.bind(this, this.addCustomDeckJson_));
+  $(".add_custom_deck_url", this.element_).click(cah.bind(this, this.addCustomDeckUrl_));
   $("select", this.optionsElement_).change(cah.bind(this, this.optionChanged_));
   $("input", this.optionsElement_).blur(cah.bind(this, this.optionChanged_));
   $(".timer_multiplier", this.optionsElement_).change(cah.bind(this, this.optionChanged_));
@@ -1479,6 +1481,38 @@ cah.Game.prototype.updateOptionsEnabled_ = function() {
   }
 };
 
+/**
+ * Upload custom deck with a given URL.
+ *
+ * @param e
+ * @private
+ */
+cah.Game.prototype.addCustomDeckUrl_ = function(e) {
+  var url = prompt("Insert a valid URL pointing to the deck.");
+  cah.Ajax.build(cah.$.AjaxOperation.ADD_CARDSET).withGameId(this.id_).withCustomDeckUrl(url).run();
+};
+
+/**
+ * Upload custom deck from JSON.
+ *
+ * @param e
+ * @private
+ */
+cah.Game.prototype.addCustomDeckJson_ = function(e) {
+  var gid = this.id_;
+  var file_input = $('#file-input')[0];
+  file_input.onchange = function (ee) {
+    var reader = new FileReader();
+    reader.readAsText(ee.target.files[0],'UTF-8');
+    reader.onload = readerEvent => {
+      var content = readerEvent.target.result;
+      cah.Ajax.build(cah.$.AjaxOperation.ADD_CARDSET).withGameId(gid).withCustomDeckJson(content).run();
+    }
+  }
+
+  file_input.click();
+};
+
 /**
  * Event handler for changing an option.
  * 

src/main/java/net/socialgamer/cah/customsets/CustomCardsService.java

@@ -90,6 +90,8 @@ public class CustomCardsService {
 
     try {
       String content = getUrlContent(url);
+      if (content == null) return null;
+
       return loadSetFromJson(content, url);
     } catch (IOException e) {
       putCache(null, INVALID_SET_CACHE_LIFETIME, url, null);