feat(jsonFilter): add optional arg to define custom indentation

also change toJson function to accomodate passing in of number of spaces

Closes #9771

src/Angular.js

@@ -964,12 +964,13 @@ function toJsonReplacer(key, value) {
  * stripped since angular uses this notation internally.
  *
  * @param {Object|Array|Date|string|number} obj Input to be serialized into JSON.
- * @param {boolean=} pretty If set to true, the JSON output will contain newlines and whitespace.
+ * @param {boolean|number=} pretty If set to true, the JSON output will contain newlines and whitespace.
+ *    If set to an integer, the JSON output will contain that many spaces per indentation (the default is 2).
  * @returns {string|undefined} JSON-ified string representing `obj`.
  */
 function toJson(obj, pretty) {
   if (typeof obj === 'undefined') return undefined;
-  return JSON.stringify(obj, toJsonReplacer, pretty ? '  ' : null);
+  return JSON.stringify(obj, toJsonReplacer, pretty === true ? 2 : pretty);
 }
 
 

src/ng/filter/filters.js

@@ -501,25 +501,31 @@ function dateFilter($locale) {
  *   the binding is automatically converted to JSON.
  *
  * @param {*} object Any JavaScript object (including arrays and primitive types) to filter.
+ * @param {number=} spacing The number of spaces to use per indentation, defaults to 2.
  * @returns {string} JSON string.
  *
  *
  * @example
    <example>
      <file name="index.html">
-       <pre>{{ {'name':'value'} | json }}</pre>
+       <pre id="default-spacing">{{ {'name':'value'} | json }}</pre>
+       <pre id="custom-spacing">{{ {'name':'value'} | json:4 }}</pre>
      </file>
      <file name="protractor.js" type="protractor">
        it('should jsonify filtered objects', function() {
-         expect(element(by.binding("{'name':'value'}")).getText()).toMatch(/\{\n  "name": ?"value"\n}/);
+         expect(element(by.id('default-spacing')).getText()).toMatch(/\{\n  "name": ?"value"\n}/);
+         expect(element(by.id('custom-spacing')).getText()).toMatch(/\{\n    "name": ?"value"\n}/);
        });
      </file>
    </example>
  *
  */
 function jsonFilter() {
-  return function(object) {
-    return toJson(object, true);
+  return function(object, spacing) {
+    if (isUndefined(spacing)) {
+        spacing = 2;
+    }
+    return toJson(object, spacing);
   };
 }
 

test/ng/filter/filtersSpec.js

@@ -210,6 +210,9 @@ describe('filters', function() {
     it('should do basic filter', function() {
       expect(filter('json')({a:"b"})).toEqual(toJson({a:"b"}, true));
     });
+    it('should allow custom indentation', function() {
+      expect(filter('json')({a:"b"}, 4)).toEqual(toJson({a:"b"}, 4));
+    });
   });
 
   describe('lowercase', function() {