feat(core): introduce NgInit directive

README.md

@@ -16,6 +16,7 @@ Angular extensions powered by community.
 + `@angular-contrib/common`
   + [`<ng-host>`][NgHost]
   + [`ngForIn`][NgForIn]
+  + [`ngInit`][NgInit]
   + [`ngNoCheck`][NgNoCheck]
   + [`ngSwitchCaseContinue`][NgSwitchContinue]
 
@@ -70,6 +71,7 @@ class AppComponent { }
 [IterableDiffersExtensibility]: https://github.com/trotyl/angular-contrib/tree/master/packages/core/iterable-differs
 [KeyValueDiffersExtensibility]: https://github.com/trotyl/angular-contrib/tree/master/packages/core/key-value-differs
 [NgForIn]: https://github.com/trotyl/angular-contrib/tree/master/packages/common/for-in
-[NgNoCheck]: https://github.com/trotyl/angular-contrib/tree/master/packages/common/no-check
+[NgInit]: https://github.com/trotyl/angular-contrib/tree/master/packages/common/init
 [NgHost]: https://github.com/trotyl/angular-contrib/tree/master/packages/common/host
+[NgNoCheck]: https://github.com/trotyl/angular-contrib/tree/master/packages/common/no-check
 [NgSwitchContinue]: https://github.com/trotyl/angular-contrib/tree/master/packages/common/switch-continue

packages/common/index.ts

@@ -1,4 +1,5 @@
 export * from './for-in/index';
 export * from './host/index';
+export * from './init/index';
 export * from './no-check/index';
 export * from './switch-continue/index';

packages/common/init/README.md

@@ -0,0 +1,35 @@
+# NgInit
+
+Helper directive to perform side-effects in template.
+
+## Type
+
+**Directive**
+
+## Provenance
+
++ https://github.com/angular/angular/issues/6585
+
+## NgModule
+
+`@angular-contrib/core#InitModule`
+
+## Usage
+
+```typescript
+@Component({
+  template: `
+    <p (ngInit)="value = 'Bar'">
+      Will be Bar: {{ value }}
+    </p>
+  `
+})
+class MyComponent {
+  value = 'Foo';
+}
+```
+
+## Note
+
++ Please do not use this when possible;
++ The order is equivant to `OnInit` hook on the given element;

packages/common/init/index.ts

@@ -0,0 +1,2 @@
+export * from './init';
+export * from './init.module';

packages/common/init/init.module.ts

@@ -0,0 +1,8 @@
+import { NgModule } from '@angular/core';
+import { NgInit } from './init';
+
+@NgModule({
+  declarations: [ NgInit ],
+  exports: [ NgInit ],
+})
+export class InitModule { }

packages/common/init/init.spec.ts

@@ -0,0 +1,34 @@
+import { Component } from '@angular/core';
+import { async, ComponentFixture, TestBed } from '@angular/core/testing';
+import { InitModule } from './init.module';
+
+describe('ngForIn', () => {
+  let fixture: ComponentFixture<TestComponent>;
+  let component: TestComponent;
+
+  beforeEach(async(() => {
+    TestBed.configureTestingModule({
+      declarations: [TestComponent],
+      imports: [InitModule],
+    }).compileComponents();
+  }));
+
+  beforeEach(() => {
+    fixture = TestBed.createComponent(TestComponent);
+    component = fixture.componentInstance;
+  });
+
+  it('should perform statement during init', () => {
+    fixture.detectChanges();
+
+    expect(fixture.nativeElement.textContent).toBe(`2`);
+  });
+});
+
+@Component({
+  selector: 'test-cmp',
+  template: `<p (ngInit)="value = 2">{{ value }}</p>`,
+})
+class TestComponent {
+  value = 1;
+}

packages/common/init/init.ts

@@ -0,0 +1,12 @@
+import { Directive, EventEmitter, OnInit, Output } from '@angular/core';
+
+@Directive({
+  selector: '[ngInit]',
+})
+export class NgInit implements OnInit {
+  @Output() ngInit = new EventEmitter<void>();
+
+  ngOnInit(): void {
+    this.ngInit.emit();
+  }
+}