angular · awiseman · Nov 20, 2015
diff --git a/modules/angular2/src/common/forms.ts b/modules/angular2/src/common/forms.ts
@@ -37,6 +37,7 @@ export {
   RequiredValidator,
   MinLengthValidator,
   MaxLengthValidator,
+  PatternValidator,
   Validator
 } from './forms/directives/validators';
 export {FormBuilder} from './forms/form_builder';

diff --git a/modules/angular2/src/common/forms/directives.ts b/modules/angular2/src/common/forms/directives.ts
@@ -14,7 +14,12 @@ import {
   SelectControlValueAccessor,
   NgSelectOption
 } from './directives/select_control_value_accessor';
-import {RequiredValidator, MinLengthValidator, MaxLengthValidator} from './directives/validators';
+import {
+  RequiredValidator,
+  MinLengthValidator,
+  MaxLengthValidator,
+  PatternValidator
+} from './directives/validators';
 
 export {NgControlName} from './directives/ng_control_name';
 export {NgFormControl} from './directives/ng_form_control';
@@ -34,7 +39,12 @@ export {
   SelectControlValueAccessor,
   NgSelectOption
 } from './directives/select_control_value_accessor';
-export {RequiredValidator, MinLengthValidator, MaxLengthValidator} from './directives/validators';
+export {
+  RequiredValidator,
+  MinLengthValidator,
+  MaxLengthValidator,
+  PatternValidator
+} from './directives/validators';
 export {NgControl} from './directives/ng_control';
 export {ControlValueAccessor} from './directives/control_value_accessor';
 
@@ -73,5 +83,6 @@ export const FORM_DIRECTIVES: Type[] = CONST_EXPR([
 
   RequiredValidator,
   MinLengthValidator,
-  MaxLengthValidator
+  MaxLengthValidator,
+  PatternValidator
 ]);
diff --git a/modules/angular2/src/common/forms/directives/validators.ts b/modules/angular2/src/common/forms/directives/validators.ts
@@ -100,3 +100,32 @@ export class MaxLengthValidator implements Validator {
 
   validate(c: Control): {[key: string]: any} { return this._validator(c); }
 }
+
+
+/**
+ * A Directive that adds the `pattern` validator to any controls marked with the
+ * `pattern` attribute, via the {@link NG_VALIDATORS} binding. Uses attribute value
+ * as the regex to validate Control value against.  Follows pattern attribute
+ * semantics; i.e. regex must match entire Control value.
+ *
+ * ### Example
+ *
+ * ```
+ * <input [ngControl]="fullName" pattern="[a-zA-Z ]*">
+ * ```
+ */
+const PATTERN_VALIDATOR = CONST_EXPR(
+    new Provider(NG_VALIDATORS, {useExisting: forwardRef(() => PatternValidator), multi: true}));
+@Directive({
+  selector: '[pattern][ngControl],[pattern][ngFormControl],[pattern][ngModel]',
+  providers: [PATTERN_VALIDATOR]
+})
+export class PatternValidator implements Validator {
+  private _validator: Function;
+
+  constructor(@Attribute("pattern") pattern: string) {
+    this._validator = Validators.pattern(pattern);
+  }
+
+  validate(c: Control): {[key: string]: any} { return this._validator(c); }
+}
diff --git a/modules/angular2/src/common/forms/validators.ts b/modules/angular2/src/common/forms/validators.ts
@@ -75,6 +75,19 @@ export class Validators {
     };
   }
 
+  /**
+   * Validator that requires a control to match a regex to its value.
+   */
+  static pattern(pattern: string): Function {
+    return (control: modelModule.Control): {[key: string]: any} => {
+      if (isPresent(Validators.required(control))) return null;
+      let regex = new RegExp(`^${pattern}$`);
+      let v: string = control.value;
+      return regex.test(v) ? null :
+                             {"pattern": {"requiredPattern": `^${pattern}$`, "actualValue": v}};
+    };
+  }
+
   /**
    * No-op validator.
    */

diff --git a/modules/angular2/test/common/forms/validators_spec.ts b/modules/angular2/test/common/forms/validators_spec.ts
@@ -66,12 +66,28 @@ export function main() {
       it("should not error on valid strings",
          () => { expect(Validators.maxLength(2)(new Control("aa"))).toEqual(null); });
 
-      it("should error on short strings", () => {
+      it("should error on long strings", () => {
         expect(Validators.maxLength(2)(new Control("aaa")))
             .toEqual({"maxlength": {"requiredLength": 2, "actualLength": 3}});
       });
     });
 
+    describe("pattern", () => {
+      it("should not error on an empty string",
+         () => { expect(Validators.pattern("[a-zA-Z ]*")(new Control(""))).toEqual(null); });
+
+      it("should not error on null",
+         () => { expect(Validators.pattern("[a-zA-Z ]*")(new Control(null))).toEqual(null); });
+
+      it("should not error on valid strings",
+         () => { expect(Validators.pattern("[a-zA-Z ]*")(new Control("aaAA"))).toEqual(null); });
+
+      it("should error on failure to match string", () => {
+        expect(Validators.pattern("[a-zA-Z ]*")(new Control("aaa0")))
+            .toEqual({"pattern": {"requiredPattern": "^[a-zA-Z ]*$", "actualValue": "aaa0"}});
+      });
+    });
+
     describe("compose", () => {
       it("should return null when given null",
          () => { expect(Validators.compose(null)).toBe(null); });

diff --git a/modules/angular2/test/public_api_spec.ts b/modules/angular2/test/public_api_spec.ts
@@ -427,6 +427,8 @@ var NG_COMMON = [
   'ObservableListDiffFactory.create():dart',
   'ObservableListDiffFactory.supports():dart',
   'ObservableListDiffFactory:dart',
+  'PatternValidator',
+  'PatternValidator.validate()',
   'PercentPipe',
   'PercentPipe.transform()',
   'RequiredValidator',
@@ -452,6 +454,7 @@ var NG_COMMON = [
   'Validators#maxLength()',
   'Validators#minLength()',
   'Validators#nullValidator()',
+  'Validators#pattern()',
   'Validators#required()',
   'RadioButtonState',
   'RadioButtonState.checked',

diff --git a/tools/public_api_guard/public_api_spec.ts b/tools/public_api_guard/public_api_spec.ts
@@ -771,6 +771,9 @@ const COMMON = [
   'NgSwitchWhen.constructor(viewContainer:ViewContainerRef, templateRef:TemplateRef, ngSwitch:NgSwitch)',
   'NgSwitchWhen.ngSwitchWhen=(value:any)',
   'NumberPipe',
+  'PatternValidator',
+  'PatternValidator.constructor(pattern:string)',
+  'PatternValidator.validate(c:Control):{[key:string]:any}',
   'PercentPipe',
   'PercentPipe.transform(value:any, args:any[]):string',
   'RequiredValidator',
@@ -794,6 +797,7 @@ const COMMON = [
   'Validators.maxLength(maxLength:number):Function',
   'Validators.minLength(minLength:number):Function',
   'Validators.nullValidator(c:any):{[key:string]:boolean}',
+  'Validators.pattern(pattern:string):Function',
   'Validators.required(control:Control):{[key:string]:boolean}',
   'RadioButtonState',
   'RadioButtonState.constructor(checked:boolean, value:string)',