angular2-contextmenu

A context menu built with Angular 2 inspired by ui.bootstrap.contextMenu. Bootstrap classes are included in the markup, but there is no explicit dependency on Bootstrap. Demo

Installation

• npm install angular2-contextmenu
• import ContextMenuModule into your app module

Usage

Declarative vs. Imperative

With version 0.2.0, there is a new declarative syntax that allows for quite a bit more flexibility and keeps html out of configuration objects. The older syntax is deprecated and will be removed in version 1.x. (I have no timeline on when I'll release 1.x, but wanted to give everyone advance warning.)

Template

<ul>
    <li *ngFor="let item of items" [contextMenu]="basicMenu" [contextMenuSubject]="item">Right Click: {{item?.name}}</li>
</ul>
<context-menu>
  <template contextMenuItem (execute)="showMessage('Hi, ' + $event.item.name)">
    Say hi!
  </template>
  <template contextMenuItem divider="true"></template>
  <template contextMenuItem let-item (execute)="showMessage($event.item.name + ' said: ' + $event.item.otherProperty)">
    Bye, {{item?.name}}
  </template>
</context-menu>

Component Code

@Component({
  ...
})
export class MyContextMenuClass {
  public items = [
      { name: 'John', otherProperty: 'Foo' },
      { name: 'Joe', otherProperty: 'Bar' }
  ];
  @ViewChild(ContextMenuComponent) public basicMenu: ContextMenuComponent;
}

Context Menu Items

• Each context menu item is a <template> element with the contextMenuItem attribute directive applied.
• If the item object is used in the context menu item template, the let-item attribute must be applied to the <template> element. ** Note: ** Make sure to use the item?.property syntax in the template rather than item.property as the item will be initially undefined.
• Every context menu item emits execute events. The $event object is of the form { event: MouseEvent, item: any } where event is the mouse click event that triggered the execution and item is the current item.
• The divider input parameter is optional. Items default to normal menu items. If divider is true, all the other inputs are ignored.
• The enabled input parameter is optional. Items are enabled by default. This can be a boolean value or a function definition that takes an item and returns a boolean.
• The visible input parameter is optional. Items are visible by default. This property enables you to show certain context menu items based on what the data item is. This can be a boolean value or a function definition that takes an item and returns a boolean.
• Within the template, you have access to any components and variables available in the outer context.

<context-menu>
  <template contextMenuItem let-item [visible]="isMenuItemType1" [enabled]="false" (execute)="showMessage('Hi, ' + $event.item.name)">
    Say hi, {{item?.name}}!  <my-component [attribute]="item"></my-component>
    With access to the outside context: {{ outsideValue }}
  </template>
</context-menu>

public outsideValue = "something";
public isMenuItemType1(item: any): boolean {
  return item.type === 'type1';
}

Binding this for visible and enabled functions

If you need access to properties in your component from within the enabled or visible functions, you'll need to pass in a version of the function with this bound to your component.

<template ... [visible]="isMenuItemOutsideValueBound">

public outsideValue = "something";
public isMenuItemOutsideValueBound = this.isMenuItemOutsideValue.bind(this);
public isMenuItemOutsideValue(item: any): boolean {
  return item.type === this.outsideValue;
}

Multiple Context Menus

You can use multiple context menus in the same component if you would like.

<ul>
    <li *ngFor="let item of items" [contextMenu]="basicMenu" [contextMenuSubject]="item">{{item?.name}}</li>
</ul>
<context-menu #basicMenu>
  ...
</context-menu>

<ul>
    <li *ngFor="let item of items" [contextMenu]="otherMenu" [contextMenuSubject]="item">{{item?.name}}</li>
</ul>
<context-menu #otherMenu>
  ...
</context-menu>

@ViewChild('basicMenu') public basicMenu: ContextMenuComponent;
@ViewChild('otherMenu') public otherMenu: ContextMenuComponent;

Context Menu In a Different Component

If your <context-menu> component is in a different component from your list, you'll need to wire up the context menu event yourself.

<ul>
    <li *ngFor="let item of items" (contextmenu)="onContextMenu($event, item)">Right Click: {{item.name}}</li>
</ul>

import { ContextMenuService } from 'angular2-contextmenu';

@Component({
  ...
})
export class MyContextMenuClass {
  public items = [
      { name: 'John', otherProperty: 'Foo' },
      { name: 'Joe', otherProperty: 'Bar' }
  ];

  constructor(private contextMenuService: ContextMenuService) {}

  public onContextMenu($event: MouseEvent, item: any): void {
    this.contextMenuService.show.next({
      event: $event,
      item: item,
    });
    $event.preventDefault();
    $event.stopPropagation();
  }
}

Triggering the Context Menu with a Different Event

The context menu can be triggered at any point using the method above. For instance, to trigger the context menu with a left click instead of a right click, use this html:

<ul>
    <li *ngFor="let item of items" (click)="onContextMenu($event, item)">Left Click: {{item.name}}</li>
</ul>

This could be (keydown), (mouseover), or (myCustomEvent) as well.

Custom Styles

The html that is generated for the context menu looks like this:

<div class="dropdown angular2-contextmenu">
  <ul class="dropdown-menu">
    <li>
      <a><!-- the template for each context menu item goes here --></a>
    </li>
  </ul>
</div>

You can key off of the angular2-contextmenu class to create your own styles. Note that the ul.dropdown-menu will have inline styles applied for position, display, left and top so that it will be positioned at the cursor when you right-click.

.angular2-contextmenu .dropdown-menu {
  border: solid 1px chartreuse;
  background-color: darkgreen;
  padding: 0;
}
.angular2-contextmenu li {
  display: block;
  border-top: solid 1px chartreuse;
  text-transform: uppercase;
  text-align: center;
}
.angular2-contextmenu li:first-child {
  border-top:none;
}
.angular2-contextmenu a {
  color:chartreuse;
  display: block;
  padding: 0.5em 1em;
}
.angular2-contextmenu a:hover {
  color:darkgreen;
  background-color:chartreuse;
}

Bootstrap 4

If you're using Bootstrap 4, you can specify a useBootstrap4 property in the forRoot function of the ContextMenuModule in order to get the appropriate class names. Like this:

@NgModule({
  import: [
    ContextMenuModule.forRoot({
      useBootstrap4: true,
    }),
  ],
})
export class AppModule {}

Or, if you want to repeat yourself, you can add a useBootstrap4 attribute to each context-menu component. Like this:

<context-menu [useBootstrap4]="true"></context-menu>

Close event emitter

There is a (close) output EventEmitter that you can subscribe to for notifications when the context menu closes (either by clicking outside or choosing a menu item).

<context-menu (close)="processContextMenuCloseEvent()"></context-menu>

CSS Transforms

The context menu will correctly position itself as long as the <context-menu> element does not have a parent element that has a complex transform applied to it. Complex in this case means anything besides a simple 2d translation. So rotate, skew, stretch, scale, z-axis translation will all cause the context menu to appear in unexpected places. The common scenario of rendering an element with transform: translate3d(0px 0px 0px) in order to trigger the browser's GPU works just fine.

Deprecated syntax

This alternate, deprecated syntax will continue working until version 1.x.

Template

<ul>
    <li *ngFor="let item of items" (contextmenu)="onContextMenu($event, item)">Right Click: {{item.name}}</li>
</ul>
<context-menu></context-menu>

Component Code

import { ContextMenuService } from 'angular2-contextmenu';

@Component({
  ...
})
export class MyContextMenuClass {
  public items = [
      { name: 'John', otherProperty: 'Foo' },
      { name: 'Joe', otherProperty: 'Bar' }
  ];

  constructor(private contextMenuService: ContextMenuService) {}

  public onContextMenu($event: MouseEvent, item: any): void {
    this.contextMenuService.show.next({
      actions: [
        {
          html: (item) => `Say hi!`,
          click: (item) => alert('Hi, ' + item.name)
        },
        {
          html: (item) => `Something else`,
          click: (item) => alert('Or not...')
        },
      ],
      event: $event,
      item: item,
    });
    $event.preventDefault();
    $event.stopPropagation();
  }
}