Merge pull request #12 from PolymerElements/fix-validate-api

refactor the validation api

Author: notwaldorf

iron-validatable-behavior.html

@@ -16,7 +16,7 @@
   /**
    * Use `Polymer.IronValidatableBehavior` to implement an element that validates user input.
    *
-   * ### Accessiblity
+   * ### Accessibility
    *
    * Changing the `invalid` property, either manually or by calling `validate()` will update the
    * `aria-invalid` attribute.
@@ -87,19 +87,35 @@
     },
 
     /**
-     * @param {Object} values Passed to the validator's `validate()` function.
-     * @return {boolean} True if `values` is valid.
+     * Returns true if the `value` is valid, and updates `invalid`. If you want
+     * your element to have custom validation logic, do not override this method;
+     * override `_getValidity(value)` instead.
+
+     * @param {Object} value The value to be validated. By default, it is passed
+     * to the validator's `validate()` function, if a validator is set.
+     * @return {boolean} True if `value` is valid.
+     */
+    validate: function(value) {
+      this.invalid = !this._getValidity(value);
+      return !this.invalid;
+    },
+
+    /**
+     * Returns true if `value` is valid.  By default, it is passed
+     * to the validator's `validate()` function, if a validator is set. You
+     * should override this method if you want to implement custom validity
+     * logic for your element.
+     *
+     * @param {Object} value The value to be validated.
+     * @return {boolean} True if `value` is valid.
      */
-    validate: function(values) {
-      var valid = true;
+
+    _getValidity: function(value) {
       if (this.hasValidator()) {
-        valid = this._validator.validate(values);
+        return this._validator.validate(value);
       }
-
-      this.invalid = !valid;
-      return valid;
+      return true;
     }
-
   };
 
 </script>