From 455432250e1d26129023eab5289f1be2f2113c67 Mon Sep 17 00:00:00 2001
From: Rachel Fenichel <fenichel@google.com>
Date: Wed, 22 Feb 2017 17:05:52 -0800
Subject: [PATCH] Use mutator extension for controls_if block

---
 blocks/logic.js    | 18 +++++++++-------
 core/block.js      |  5 +++++
 core/extensions.js | 54 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 69 insertions(+), 8 deletions(-)

diff --git a/blocks/logic.js b/blocks/logic.js
index a9d165314..051c46fdf 100644
--- a/blocks/logic.js
+++ b/blocks/logic.js
@@ -86,7 +86,8 @@ Blockly.defineBlocksWithJsonArray([  // BEGIN JSON EXTRACT
     "nextStatement": null,
     "colour": "%{BKY_LOGIC_HUE}",
     "helpUrl": "%{BKY_CONTROLS_IF_HELPURL}",
-    "extensions": ["controls_if_mutator"]
+    "mutator": "controls_if_mutator",
+    "extensions": ["controls_if_tooltip"]
   },
   // If/else block that does not use a mutator.
   {
@@ -457,15 +458,16 @@ Blockly.Constants.Logic.CONTROLS_IF_MUTATOR_MIXIN = {
   }
 };
 
+Blockly.Extensions.registerMutator('controls_if_mutator',
+    Blockly.Constants.Logic.CONTROLS_IF_MUTATOR_MIXIN,
+    ['controls_if_elseif', 'controls_if_else']);
 /**
  * "controls_if" extension function. Adds mutator, shape updating methods, and
  * dynamic tooltip to "controls_if" blocks.
  * @this Blockly.Block
  * @package
  */
-Blockly.Constants.Logic.CONTROLS_IF_MUTATOR_EXTENSION = function() {
-  this.setMutator(new Blockly.Mutator(['controls_if_elseif', 'controls_if_else']));
-  this.mixin(Blockly.Constants.Logic.CONTROLS_IF_MUTATOR_MIXIN);
+Blockly.Constants.Logic.CONTROLS_IF_TOOLTIP_EXTENSION = function() {
 
   this.setTooltip(function() {
     if (!this.elseifCount_ && !this.elseCount_) {
@@ -481,11 +483,11 @@ Blockly.Constants.Logic.CONTROLS_IF_MUTATOR_EXTENSION = function() {
   }.bind(this));
 };
 
-Blockly.Extensions.register('controls_if_mutator',
-  Blockly.Constants.Logic.CONTROLS_IF_MUTATOR_EXTENSION);
+Blockly.Extensions.register('controls_if_tooltip',
+  Blockly.Constants.Logic.CONTROLS_IF_TOOLTIP_EXTENSION);
 
 /**
- * Corrects the logic_compate dropdown label with respect to language direction.
+ * Corrects the logic_compare dropdown label with respect to language direction.
  * @this Blockly.Block
  * @package
  */
@@ -513,7 +515,7 @@ Blockly.Constants.Logic.fixLogicCompareRtlOpLabels =
   };
 
 /**
- * Adds dynamic type validation for the left and right sides of a logic_compate block.
+ * Adds dynamic type validation for the left and right sides of a logic_compare block.
  * @mixin
  * @augments Blockly.Block
  * @package
diff --git a/core/block.js b/core/block.js
index 4ad3117b0..73abaebf0 100644
--- a/core/block.js
+++ b/core/block.js
@@ -985,6 +985,11 @@ Blockly.Block.prototype.appendDummyInput = function(opt_name) {
  * @param {!Object} json Structured data describing the block.
  */
 Blockly.Block.prototype.jsonInit = function(json) {
+  // Add the mutator to the block
+  if (json['mutator'] !== undefined) {
+    Blockly.Extensions.apply(json['mutator'], this);
+  }
+
   // Validate inputs.
   goog.asserts.assert(json['output'] == undefined ||
       json['previousStatement'] == undefined,
diff --git a/core/extensions.js b/core/extensions.js
index ad9db0dc6..b64a8ca21 100644
--- a/core/extensions.js
+++ b/core/extensions.js
@@ -76,6 +76,60 @@ Blockly.Extensions.registerMixin = function(name, mixinObj) {
   });
 };
 
+/**
+ * Registers a new extension function that adds a mutator to the block.
+ * A mutator must have, at minimum, domToMutation and mutationToDom.  When
+ * mixing it into a block, the wrapper will check that domToMutation and
+ * mutationToDom are not already defined on that block.
+ * The wrapper may also add a mutator dialog to the block.
+ * @param {string} name The name of this mutator extension.
+ * @param {!Object} mixinObj The values to mix in.
+ * @param {Array.<string>=} opt_blockList A list of blocks to appear in the flyout
+ *     of the mutator dialog.  If a list is passed in, the extension will also
+ *     add a mutator dialog to the block.
+ * @throws {Error} if the extension name is empty; the extension is already
+ *     registered; or domToMutation and mutationToDom are wrong.
+ */
+Blockly.Extensions.registerMutator = function(name, mixinObj, opt_blockList) {
+  Blockly.Extensions.register(name, function() {
+    // Check that the mixin object makese sense.
+    if (!mixinObj.hasOwnProperty('domToMutation')) {
+      throw new Error('Error: mutation name "' + name + '" is missing domToMutation');
+    } else if (typeof mixinObj['domToMutation'] !== "function") {
+      throw new Error('Error: mutation name "' + name +
+          '" has a domToMutation that is not a function');
+    }
+
+    if (!mixinObj.hasOwnProperty('mutationToDom')) {
+      throw new Error('Error: mutation name "' + name + '" is missing mutationToDom');
+    } else if (typeof mixinObj['mutationToDom'] !== "function") {
+      throw new Error('Error: mutation name "' + name +
+          '" has a mutationToDom that is not a function');
+    }
+
+    // Check that we're not overwriting anything.
+    if (this.hasOwnProperty('domToMutation')) {
+      throw new Error('Error: tried to apply mutation "' + name +
+          '" to a block that already has a domToMutation function.  Block id: ' +
+          this.id);
+    }
+
+    if (this.hasOwnProperty('mutationToDom')) {
+      throw new Error('Error: tried to apply mutation "' + name +
+          '" to a block that already has a domToMutation function.  Block id: ' +
+          this.id);
+    }
+
+    // Possibly add a mutator dialog.
+    if (opt_blockList) {
+      this.setMutator(new Blockly.Mutator(opt_blockList));
+    }
+
+    // Finally, mixin the object.
+    this.mixin(mixinObj);
+  });
+};
+
 /**
  * Applies an extension method to a block. This should only be called during
  * block construction.