angular-docs-cn/packages/core/test/acceptance/content_spec.ts

/**
 * @license
 * Copyright Google Inc. All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

import {CommonModule} from '@angular/common';
import {ChangeDetectorRef, Component, Directive, TemplateRef, ViewChild, ViewContainerRef} from '@angular/core';
import {Input} from '@angular/core/src/metadata';
import {TestBed} from '@angular/core/testing';
import {By} from '@angular/platform-browser';
import {expect} from '@angular/platform-browser/testing/src/matchers';

describe('projection', () => {

  function getElementHtml(element: HTMLElement) {
    return element.innerHTML.replace(/<!--(\W|\w)*?-->/g, '')
        .replace(/\sng-reflect-\S*="[^"]*"/g, '');
  }

  it('should project content', () => {
    @Component({selector: 'child', template: `<div><ng-content></ng-content></div>`})
    class Child {
    }

    @Component({selector: 'parent', template: '<child>content</child>'})
    class Parent {
    }

    TestBed.configureTestingModule({declarations: [Parent, Child]});
    const fixture = TestBed.createComponent(Parent);
    fixture.detectChanges();

    expect(fixture.nativeElement.innerHTML).toBe(`<child><div>content</div></child>`);
  });

  it('should project content when <ng-content> is at a template root', () => {
    @Component({
      selector: 'child',
      template: '<ng-content></ng-content>',
    })
    class Child {
    }

    @Component({
      selector: 'parent',
      template: '<child>content</child>',
    })
    class Parent {
    }

    TestBed.configureTestingModule({declarations: [Parent, Child]});
    const fixture = TestBed.createComponent(Parent);
    fixture.detectChanges();

    expect(fixture.nativeElement.innerHTML).toBe(`<child>content</child>`);
  });

  it('should project content with siblings', () => {
    @Component({selector: 'child', template: '<ng-content></ng-content>'})
    class Child {
    }

    @Component({selector: 'parent', template: `<child>before<div>content</div>after</child>`})
    class Parent {
    }


    TestBed.configureTestingModule({declarations: [Parent, Child]});
    const fixture = TestBed.createComponent(Parent);
    fixture.detectChanges();

    expect(fixture.nativeElement.innerHTML).toBe(`<child>before<div>content</div>after</child>`);
  });

  it('should be able to re-project content', () => {
    @Component({selector: 'grand-child', template: `<div><ng-content></ng-content></div>`})
    class GrandChild {
    }

    @Component(
        {selector: 'child', template: `<grand-child><ng-content></ng-content></grand-child>`})
    class Child {
    }

    @Component({
      selector: 'parent',
      template: `<child><b>Hello</b>World!</child>`,
    })
    class Parent {
    }

    TestBed.configureTestingModule({declarations: [Parent, Child, GrandChild]});
    const fixture = TestBed.createComponent(Parent);
    fixture.detectChanges();

    expect(fixture.nativeElement.innerHTML)
        .toBe('<child><grand-child><div><b>Hello</b>World!</div></grand-child></child>');
  });

  it('should project components', () => {
    @Component({
      selector: 'child',
      template: `<div><ng-content></ng-content></div>`,
    })
    class Child {
    }

    @Component({
      selector: 'projected-comp',
      template: 'content',
    })
    class ProjectedComp {
    }

    @Component({selector: 'parent', template: `<child><projected-comp></projected-comp></child>`})
    class Parent {
    }

    TestBed.configureTestingModule({declarations: [Parent, Child, ProjectedComp]});
    const fixture = TestBed.createComponent(Parent);
    fixture.detectChanges();

    expect(fixture.nativeElement.innerHTML)
        .toBe('<child><div><projected-comp>content</projected-comp></div></child>');
  });

  it('should project components that have their own projection', () => {
    @Component({selector: 'child', template: `<div><ng-content></ng-content></div>`})
    class Child {
    }

    @Component({selector: 'projected-comp', template: `<p><ng-content></ng-content></p>`})
    class ProjectedComp {
    }

    @Component({
      selector: 'parent',
      template: `
        <child>
          <projected-comp><div>Some content</div>Other content</projected-comp>
        </child>`,
    })
    class Parent {
    }

    TestBed.configureTestingModule({declarations: [Parent, Child, ProjectedComp]});
    const fixture = TestBed.createComponent(Parent);
    fixture.detectChanges();

    expect(fixture.nativeElement.innerHTML)
        .toBe(
            `<child><div><projected-comp><p><div>Some content</div>Other content</p></projected-comp></div></child>`);
  });

  it('should project into dynamic views (with createEmbeddedView)', () => {
    @Component({
      selector: 'child',
      template: `Before-<ng-template [ngIf]="showing"><ng-content></ng-content></ng-template>-After`
    })
    class Child {
      showing = false;
    }

    @Component({selector: 'parent', template: `<child><div>A</div>Some text</child>`})
    class Parent {
    }

    TestBed.configureTestingModule({declarations: [Parent, Child], imports: [CommonModule]});

    const fixture = TestBed.createComponent(Parent);
    const childDebugEl = fixture.debugElement.query(By.directive(Child));
    const childInstance = childDebugEl.injector.get(Child);
    const childElement = childDebugEl.nativeElement as HTMLElement;

    childInstance.showing = true;
    fixture.detectChanges();

    expect(getElementHtml(childElement)).toBe(`Before-<div>A</div>Some text-After`);

    childInstance.showing = false;
    fixture.detectChanges();

    expect(getElementHtml(childElement)).toBe(`Before--After`);

    childInstance.showing = true;
    fixture.detectChanges();
    expect(getElementHtml(childElement)).toBe(`Before-<div>A</div>Some text-After`);
  });

  it('should project into dynamic views with specific selectors', () => {
    @Component({
      selector: 'child',
      template: `
        <ng-content></ng-content>
        Before-
        <ng-template [ngIf]="showing">
          <ng-content select="div"></ng-content>
        </ng-template>
        -After`
    })
    class Child {
      showing = false;
    }

    @Component({
      selector: 'parent',
      template: `
        <child>
          <div>A</div>
          <span>B</span>
        </child>
      `
    })
    class Parent {
    }

    TestBed.configureTestingModule({declarations: [Parent, Child], imports: [CommonModule]});

    const fixture = TestBed.createComponent(Parent);
    const childDebugEl = fixture.debugElement.query(By.directive(Child));
    const childInstance = childDebugEl.injector.get(Child);

    childInstance.showing = true;
    fixture.detectChanges();

    expect(getElementHtml(fixture.nativeElement))
        .toBe('<child><span>B</span> Before- <div>A</div> -After</child>');

    childInstance.showing = false;
    fixture.detectChanges();
    expect(getElementHtml(fixture.nativeElement))
        .toBe('<child><span>B</span> Before-  -After</child>');

    childInstance.showing = true;
    fixture.detectChanges();
    expect(getElementHtml(fixture.nativeElement))
        .toBe('<child><span>B</span> Before- <div>A</div> -After</child>');
  });

  it('should project if <ng-content> is in a template that has different declaration/insertion points',
     () => {
       @Component(
           {selector: 'comp', template: `<ng-template><ng-content></ng-content></ng-template>`})
       class Comp {
         @ViewChild(TemplateRef, {static: true}) template !: TemplateRef<any>;
       }

       @Directive({selector: '[trigger]'})
       class Trigger {
         @Input() trigger !: Comp;

         constructor(public vcr: ViewContainerRef) {}

         open() { this.vcr.createEmbeddedView(this.trigger.template); }
       }

       @Component({
         selector: 'parent',
         template: `
        <button [trigger]="comp"></button>
        <comp #comp>Some content</comp>
      `
       })
       class Parent {
       }

       TestBed.configureTestingModule({declarations: [Parent, Trigger, Comp]});

       const fixture = TestBed.createComponent(Parent);
       const trigger = fixture.debugElement.query(By.directive(Trigger)).injector.get(Trigger);
       fixture.detectChanges();

       expect(getElementHtml(fixture.nativeElement)).toBe(`<button></button><comp></comp>`);

       trigger.open();
       expect(getElementHtml(fixture.nativeElement))
           .toBe(`<button></button>Some content<comp></comp>`);
     });

  // https://stackblitz.com/edit/angular-ceqmnw?file=src%2Fapp%2Fapp.component.ts
  it('should project nodes into the last ng-content unrolled by ngFor', () => {
    @Component({
      selector: 'child',
      template:
          `<div *ngFor="let item of [1, 2]; let i = index">({{i}}):<ng-content></ng-content></div>`
    })
    class Child {
    }

    @Component({selector: 'parent', template: `<child>content</child>`})
    class Parent {
    }

    TestBed.configureTestingModule({declarations: [Parent, Child], imports: [CommonModule]});
    const fixture = TestBed.createComponent(Parent);
    fixture.detectChanges();

    expect(getElementHtml(fixture.nativeElement))
        .toBe('<child><div>(0):</div><div>(1):content</div></child>');
  });

  it('should handle projected containers inside other containers', () => {
    @Component({selector: 'nested-comp', template: `<div>Child content</div>`})
    class NestedComp {
    }

    @Component({
      selector: 'root-comp',
      template: `<ng-content></ng-content>`,
    })
    class RootComp {
    }

    @Component({
      selector: 'my-app',
      template: `
        <root-comp>
          <ng-container *ngFor="let item of items; last as last">
            <nested-comp *ngIf="!last"></nested-comp>
          </ng-container>
        </root-comp>
      `
    })
    class MyApp {
      items = [1, 2];
    }

    TestBed.configureTestingModule(
        {declarations: [MyApp, RootComp, NestedComp], imports: [CommonModule]});
    const fixture = TestBed.createComponent(MyApp);
    fixture.detectChanges();

    // expecting # of divs to be (items.length - 1), since last element is filtered out by *ngIf,
    // this applies to all other assertions below
    expect(fixture.nativeElement.querySelectorAll('div').length).toBe(1);

    fixture.componentInstance.items = [3, 4, 5];
    fixture.detectChanges();
    expect(fixture.nativeElement.querySelectorAll('div').length).toBe(2);

    fixture.componentInstance.items = [6, 7, 8, 9];
    fixture.detectChanges();
    expect(fixture.nativeElement.querySelectorAll('div').length).toBe(3);
  });

  it('should handle projection into element containers at the view root', () => {
    @Component({
      selector: 'root-comp',
      template: `
        <ng-template [ngIf]="show">
          <ng-container>
            <ng-content></ng-content>
          </ng-container>
        </ng-template>`,
    })
    class RootComp {
      @Input() show: boolean = true;
    }

    @Component({
      selector: 'my-app',
      template: `<root-comp [show]="show"><div></div></root-comp>
      `
    })
    class MyApp {
      show = true;
    }

    TestBed.configureTestingModule({declarations: [MyApp, RootComp]});
    const fixture = TestBed.createComponent(MyApp);

    fixture.detectChanges();
    expect(fixture.nativeElement.querySelectorAll('div').length).toBe(1);

    fixture.componentInstance.show = false;
    fixture.detectChanges();
    expect(fixture.nativeElement.querySelectorAll('div').length).toBe(0);
  });

  it('should handle projection of views with element containers at the root', () => {
    @Component({
      selector: 'root-comp',
      template: `<ng-template [ngIf]="show"><ng-content></ng-content></ng-template>`,
    })
    class RootComp {
      @Input() show: boolean = true;
    }

    @Component({
      selector: 'my-app',
      template: `<root-comp [show]="show"><ng-container><div></div></ng-container></root-comp>`
    })
    class MyApp {
      show = true;
    }

    TestBed.configureTestingModule({declarations: [MyApp, RootComp]});
    const fixture = TestBed.createComponent(MyApp);

    fixture.detectChanges();
    expect(fixture.nativeElement.querySelectorAll('div').length).toBe(1);

    fixture.componentInstance.show = false;
    fixture.detectChanges();
    expect(fixture.nativeElement.querySelectorAll('div').length).toBe(0);
  });

  it('should handle re-projection at the root of an embedded view', () => {
    @Component({
      selector: 'child-comp',
      template: `<ng-template [ngIf]="show"><ng-content></ng-content></ng-template>`,
    })
    class ChildComp {
      @Input() show: boolean = true;
    }

    @Component({
      selector: 'parent-comp',
      template: `<child-comp [show]="show"><ng-content></ng-content></child-comp>`
    })
    class ParentComp {
      @Input() show: boolean = true;
    }

    @Component(
        {selector: 'my-app', template: `<parent-comp [show]="show"><div></div></parent-comp>`})
    class MyApp {
      show = true;
    }

    TestBed.configureTestingModule({declarations: [MyApp, ParentComp, ChildComp]});
    const fixture = TestBed.createComponent(MyApp);
    fixture.detectChanges();
    expect(fixture.nativeElement.querySelectorAll('div').length).toBe(1);

    fixture.componentInstance.show = false;
    fixture.detectChanges();
    expect(fixture.nativeElement.querySelectorAll('div').length).toBe(0);
  });

  describe('with selectors', () => {
    // https://stackblitz.com/edit/angular-psokum?file=src%2Fapp%2Fapp.module.ts
    it('should project nodes where attribute selector matches a binding', () => {
      @Component({
        selector: 'child',
        template: `<ng-content select="[title]"></ng-content>`,
      })
      class Child {
      }

      @Component({
        selector: 'parent',
        template: `<child><span [title]="'Some title'">Has title</span></child>`
      })
      class Parent {
      }

      TestBed.configureTestingModule({declarations: [Child, Parent]});
      const fixture = TestBed.createComponent(Parent);
      fixture.detectChanges();

      expect(getElementHtml(fixture.nativeElement))
          .toEqual('<child><span title="Some title">Has title</span></child>');

    });

    it('should match selectors against projected containers', () => {
      @Component(
          {selector: 'child', template: `<span><ng-content select="div"></ng-content></span>`})
      class Child {
      }

      @Component({template: `<child><div *ngIf="value">content</div></child>`})
      class Parent {
        value = false;
      }
      TestBed.configureTestingModule({declarations: [Child, Parent]});
      const fixture = TestBed.createComponent(Parent);

      fixture.componentInstance.value = true;
      fixture.detectChanges();

      expect(getElementHtml(fixture.nativeElement))
          .toEqual('<child><span><div>content</div></span></child>');
    });
  });

  it('should handle projected containers inside other containers', () => {
    @Component({
      selector: 'child-comp',  //
      template: '<ng-content></ng-content>'
    })
    class ChildComp {
    }

    @Component({
      selector: 'root-comp',  //
      template: '<ng-content></ng-content>'
    })
    class RootComp {
    }

    @Component({
      selector: 'my-app',
      template: `
        <root-comp>
          <ng-container *ngFor="let item of items; last as last">
            <child-comp *ngIf="!last">{{ item }}|</child-comp>
          </ng-container>
        </root-comp>
      `
    })
    class MyApp {
      items: number[] = [1, 2, 3];
    }

    TestBed.configureTestingModule({declarations: [ChildComp, RootComp, MyApp]});
    const fixture = TestBed.createComponent(MyApp);
    fixture.detectChanges();

    // expecting # of elements to be (items.length - 1), since last element is filtered out by
    // *ngIf, this applies to all other assertions below
    expect(fixture.nativeElement).toHaveText('1|2|');

    fixture.componentInstance.items = [4, 5];
    fixture.detectChanges();
    expect(fixture.nativeElement).toHaveText('4|');

    fixture.componentInstance.items = [6, 7, 8, 9];
    fixture.detectChanges();
    expect(fixture.nativeElement).toHaveText('6|7|8|');
  });

  it('should project content if the change detector has been detached', () => {
    @Component({selector: 'my-comp', template: '<ng-content></ng-content>'})
    class MyComp {
      constructor(changeDetectorRef: ChangeDetectorRef) { changeDetectorRef.detach(); }
    }

    @Component({
      selector: 'my-app',
      template: `
        <my-comp>
          <p>hello</p>
        </my-comp>
      `
    })
    class MyApp {
    }

    TestBed.configureTestingModule({declarations: [MyComp, MyApp]});
    const fixture = TestBed.createComponent(MyApp);
    fixture.detectChanges();

    expect(fixture.nativeElement).toHaveText('hello');
  });

  it('should support ngProjectAs on elements (including <ng-content>)', () => {
    @Component({
      selector: 'card',
      template: `
        <ng-content select="[card-title]"></ng-content>
        ---
        <ng-content select="[card-content]"></ng-content>
      `
    })
    class Card {
    }

    @Component({
      selector: 'card-with-title',
      template: `
        <card>
         <h1 ngProjectAs="[card-title]">Title</h1>
         <ng-content ngProjectAs="[card-content]"></ng-content>
        </card>
      `
    })
    class CardWithTitle {
    }

    @Component({
      selector: 'app',
      template: `
        <card-with-title>content</card-with-title>
      `
    })
    class App {
    }

    TestBed.configureTestingModule({declarations: [Card, CardWithTitle, App]});
    const fixture = TestBed.createComponent(App);
    fixture.detectChanges();

    // Compare the text output, because Ivy and ViewEngine produce slightly different HTML.
    expect(fixture.nativeElement.textContent).toContain('Title --- content');
  });

  it('should not match multiple selectors in ngProjectAs', () => {
    @Component({
      selector: 'card',
      template: `
        <ng-content select="[card-title]"></ng-content>
        content
      `
    })
    class Card {
    }

    @Component({
      template: `
        <card>
         <h1 ngProjectAs="[non-existing-title-slot],[card-title]">Title</h1>
        </card>
      `
    })
    class App {
    }

    TestBed.configureTestingModule({declarations: [Card, App]});
    const fixture = TestBed.createComponent(App);
    fixture.detectChanges();

    // Compare the text output, because Ivy and ViewEngine produce slightly different HTML.
    expect(fixture.nativeElement.textContent).not.toContain('Title content');
  });

  describe('on inline templates (e.g.  *ngIf)', () => {
    it('should work when matching the element name', () => {
      let divDirectives = 0;
      @Component({selector: 'selector-proj', template: '<ng-content select="div"></ng-content>'})
      class SelectedNgContentComp {
      }

      @Directive({selector: 'div'})
      class DivDirective {
        constructor() { divDirectives++; }
      }

      @Component({
        selector: 'main-selector',
        template: '<selector-proj><div x="true" *ngIf="true">Hello world!</div></selector-proj>'
      })
      class SelectorMainComp {
      }

      TestBed.configureTestingModule(
          {declarations: [DivDirective, SelectedNgContentComp, SelectorMainComp]});
      const fixture = TestBed.createComponent<SelectorMainComp>(SelectorMainComp);

      fixture.detectChanges();
      expect(fixture.nativeElement).toHaveText('Hello world!');
      expect(divDirectives).toEqual(1);
    });

    it('should work when matching attributes', () => {
      let xDirectives = 0;
      @Component({selector: 'selector-proj', template: '<ng-content select="[x]"></ng-content>'})
      class SelectedNgContentComp {
      }

      @Directive({selector: '[x]'})
      class XDirective {
        constructor() { xDirectives++; }
      }

      @Component({
        selector: 'main-selector',
        template: '<selector-proj><div x="true" *ngIf="true">Hello world!</div></selector-proj>'
      })
      class SelectorMainComp {
      }

      TestBed.configureTestingModule(
          {declarations: [XDirective, SelectedNgContentComp, SelectorMainComp]});
      const fixture = TestBed.createComponent<SelectorMainComp>(SelectorMainComp);

      fixture.detectChanges();
      expect(fixture.nativeElement).toHaveText('Hello world!');
      expect(xDirectives).toEqual(1);
    });

    it('should work when matching classes', () => {
      let xDirectives = 0;
      @Component({selector: 'selector-proj', template: '<ng-content select=".x"></ng-content>'})
      class SelectedNgContentComp {
      }

      @Directive({selector: '.x'})
      class XDirective {
        constructor() { xDirectives++; }
      }

      @Component({
        selector: 'main-selector',
        template: '<selector-proj><div class="x" *ngIf="true">Hello world!</div></selector-proj>'
      })
      class SelectorMainComp {
      }

      TestBed.configureTestingModule(
          {declarations: [XDirective, SelectedNgContentComp, SelectorMainComp]});
      const fixture = TestBed.createComponent<SelectorMainComp>(SelectorMainComp);

      fixture.detectChanges();
      expect(fixture.nativeElement).toHaveText('Hello world!');
      expect(xDirectives).toEqual(1);
    });

    it('should ignore synthesized attributes (e.g. ngTrackBy)', () => {
      @Component(
          {selector: 'selector-proj', template: '<ng-content select="[ngTrackBy]"></ng-content>'})
      class SelectedNgContentComp {
      }

      @Component({
        selector: 'main-selector',
        template:
            'inline(<selector-proj><div *ngFor="let item of items trackBy getItemId">{{item.name}}</div></selector-proj>)' +
            'ng-template(<selector-proj><ng-template ngFor [ngForOf]="items" let-item ngTrackBy="getItemId"><div>{{item.name}}</div></ng-template></selector-proj>)'
      })
      class SelectorMainComp {
        items = [
          {id: 1, name: 'one'},
          {id: 2, name: 'two'},
          {id: 3, name: 'three'},
        ];
        getItemId(item: {id: number}) { return item.id; }
      }

      TestBed.configureTestingModule({declarations: [SelectedNgContentComp, SelectorMainComp]});
      const fixture = TestBed.createComponent<SelectorMainComp>(SelectorMainComp);

      fixture.detectChanges();
      expect(fixture.nativeElement).toHaveText('inline()ng-template(onetwothree)');
    });

    describe('on containers', () => {
      it('should work when matching attributes', () => {
        let xDirectives = 0;
        @Component({selector: 'selector-proj', template: '<ng-content select="[x]"></ng-content>'})
        class SelectedNgContentComp {
        }

        @Directive({selector: '[x]'})
        class XDirective {
          constructor() { xDirectives++; }
        }

        @Component({
          selector: 'main-selector',
          template:
              '<selector-proj><ng-container x="true">Hello world!</ng-container></selector-proj>'
        })
        class SelectorMainComp {
        }

        TestBed.configureTestingModule(
            {declarations: [XDirective, SelectedNgContentComp, SelectorMainComp]});
        const fixture = TestBed.createComponent<SelectorMainComp>(SelectorMainComp);

        fixture.detectChanges();
        expect(fixture.nativeElement).toHaveText('Hello world!');
        expect(xDirectives).toEqual(1);
      });

      it('should work when matching classes', () => {
        let xDirectives = 0;
        @Component({selector: 'selector-proj', template: '<ng-content select=".x"></ng-content>'})
        class SelectedNgContentComp {
        }

        @Directive({selector: '.x'})
        class XDirective {
          constructor() { xDirectives++; }
        }

        @Component({
          selector: 'main-selector',
          template:
              '<selector-proj><ng-container class="x">Hello world!</ng-container></selector-proj>'
        })
        class SelectorMainComp {
        }

        TestBed.configureTestingModule(
            {declarations: [XDirective, SelectedNgContentComp, SelectorMainComp]});
        const fixture = TestBed.createComponent<SelectorMainComp>(SelectorMainComp);

        fixture.detectChanges();
        expect(fixture.nativeElement).toHaveText('Hello world!');
        expect(xDirectives).toEqual(1);
      });
    });
  });
});