Issue 3222 - Expose filter type as a string property

lib/filterClasses.js

Index: lib/filterClasses.js
===================================================================
--- a/lib/filterClasses.js
+++ b/lib/filterClasses.js
@@ -45,16 +45,25 @@ Filter.prototype =
 
   /**
    * Filter subscriptions the filter belongs to
    * @type Subscription[]
    */
   subscriptions: null,
 
   /**
+   * Filter type as a string, e.g. "blocking".
+   * @type String
+   */
+  get type()
+  {
+    throw new Error("Please define filter type in the subclass");
+  },
+
+  /**
    * Serializes the filter to an array of strings for writing out on the disk.
    * @param {string[]} buffer  buffer to push the serialization results into
    */
   serialize: function(buffer)
   {
     buffer.push("[Filter]");
     buffer.push("text=" + this.text);
   },
@@ -201,16 +210,18 @@ function InvalidFilter(text, reason)
   this.reason = reason;
 }
 exports.InvalidFilter = InvalidFilter;
 
 InvalidFilter.prototype =
 {
   __proto__: Filter.prototype,
 
+  type: "invalid",
+
   /**
    * Reason why this filter is invalid
    * @type String
    */
   reason: null,
 
   /**
    * See Filter.serialize()
@@ -229,16 +240,18 @@ function CommentFilter(text)
   Filter.call(this, text);
 }
 exports.CommentFilter = CommentFilter;
 
 CommentFilter.prototype =
 {
   __proto__: Filter.prototype,
 
+  type: "comment",
+
   /**
    * See Filter.serialize()
    */
   serialize: function(buffer) {}
 };
 
 /**
  * Abstract base class for filters that can get hits
@@ -796,16 +809,18 @@ function BlockingFilter(text, regexpSour
   this.collapse = collapse;
 }
 exports.BlockingFilter = BlockingFilter;
 
 BlockingFilter.prototype =
 {
   __proto__: RegExpFilter.prototype,
 
+  type: "blocking",
+
   /**
    * Defines whether the filter should collapse blocked content. Can be null (use the global preference).
    * @type Boolean
    */
   collapse: null
 };
 
 /**
@@ -823,17 +838,19 @@ BlockingFilter.prototype =
 function WhitelistFilter(text, regexpSource, contentType, matchCase, domains, thirdParty, sitekeys)
 {
   RegExpFilter.call(this, text, regexpSource, contentType, matchCase, domains, thirdParty, sitekeys);
 }
 exports.WhitelistFilter = WhitelistFilter;
 
 WhitelistFilter.prototype =
 {
-  __proto__: RegExpFilter.prototype
+  __proto__: RegExpFilter.prototype,
+
+  type: "whitelist"
 };
 
 /**
  * Base class for element hiding filters
  * @param {String} text see Filter()
  * @param {String} [domains] Host names or domains the filter should be restricted to
  * @param {String} selector   CSS selector for the HTML elements that should be hidden
  * @constructor
@@ -954,17 +971,19 @@ ElemHideBase.fromText = function(text, d
 function ElemHideFilter(text, domains, selector)
 {
   ElemHideBase.call(this, text, domains, selector);
 }
 exports.ElemHideFilter = ElemHideFilter;
 
 ElemHideFilter.prototype =
 {
-  __proto__: ElemHideBase.prototype
+  __proto__: ElemHideBase.prototype,
+
+  type: "elemhide"
 };
 
 /**
  * Class for element hiding exceptions
  * @param {String} text see Filter()
  * @param {String} domains  see ElemHideBase()
  * @param {String} selector see ElemHideBase()
  * @constructor
@@ -973,17 +992,19 @@ ElemHideFilter.prototype =
 function ElemHideException(text, domains, selector)
 {
   ElemHideBase.call(this, text, domains, selector);
 }
 exports.ElemHideException = ElemHideException;
 
 ElemHideException.prototype =
 {
-  __proto__: ElemHideBase.prototype
+  __proto__: ElemHideBase.prototype,
+
+  type: "elemhideexception"
 };
 
 /**
  * Class for CSS property filters
  * @param {String} text           see Filter()
  * @param {String} domains        see ElemHideBase()
  * @param {String} selector       see ElemHideBase()
  * @param {String} regexpSource   see CSSPropertyFilter.regexpSource
@@ -1002,16 +1023,18 @@ function CSSPropertyFilter(text, domains
   this.selectorSuffix = selectorSuffix;
 }
 exports.CSSPropertyFilter = CSSPropertyFilter;
 
 CSSPropertyFilter.prototype =
 {
   __proto__: ElemHideBase.prototype,
 
+  type: "cssproperty",
+
   /**
    * Expression from which a regular expression should be generated for matching
    * CSS properties - for delayed creation of the regexpString property
    * @type String
    */
   regexpSource: null,
   /**
    * Substring of CSS selector before properties for the HTML elements that