ngx-components is a components collection and data access layer for Angular applications. It allows to access our platform from within an Angular application as well as to provide the core components. To achieve this the ngx-components consists of two basic imports:
@c8y/ngx-components) which contains all core components like title, navigator or tabs.@c8y/ngx-components/api) which enables dependency injection of the @c8y/client services.The full documentation of all modules and components can be found here
If you do not use the @c8y/cli to bootstrap a new application you first need to install the package:
$ npm install @c8y/ngx-componentsNext, you can add the ngx-components modules to your app module (e.g. app.module.ts):
import { NgModule } from '@angular/core';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { RouterModule as ngRouterModule } from '@angular/router';
import { CoreModule, BootstrapComponent, RouterModule } from '@c8y/ngx-components';
@NgModule({
imports: [
BrowserAnimationsModule,
RouterModule.forRoot(),
ngRouterModule.forRoot([], { enableTracing: false, useHash: true }), // 1
CoreModule.forRoot() // 2
],
bootstrap: [BootstrapComponent] // 3
})
export class AppModule {}
useHash navigation to true as the platform does not support pushStateCoreModule to allow the use of the c8y- prefixed components.BootstrapComponent which will use the <c8y-bootstrap> component to initialize the root application. Alternatively, you can bootstrap a component of your choice and include that tag into its template or only reuse the given components.To extend and compose an application, ngx-components provide four core architecture concepts called Extensions points:
Content Projection (CP):
This concept allows to project content from one component to another. For example, you can configure the title of a page by setting a <c8y-title> in any other component. The content of the <c8y-title> tag is then projected to an outlet component, which is placed in the header bar. The benefit of this concept is that you can place anything into the projected content, for example you can project another custom component into the title.
A good example to use this concept is the c8y-action-bar-item which uses a routerLink directive from Angular to route to a different context:
<c8y-action-bar-item [placement]="'right'">
<a class="btn btn-link" routerLink="add">
<i c8yIcon="plus-square"></i> {{'Add' | translate}}
</a>
</c8y-action-bar-item>The above example gives you an action bar item in the header bar, regardless in which component you define it. If the component is initialized the item is shown and it is removed on destroy.
Multi Provider (MP):
The Multi Provider extension allows a declarative approach to extend the application. Instead of defining it in the template, you extend an already defined factory via a HOOK. This hook gets executed if the application state changes. The return values are then injected into the page. You can use the normal dependency injection system of Angular and as a result you can usually return an Observable, Promise or Array of a certain type. As an example we can define the tabs of certain routes by hooking into the HOOK_TABS provider:
import { Injectable } from '@angular/core';
import { Router } from '@angular/router';
import { Tab, TabFactory, _ } from '@c8y/ngx-components';
@Injectable()
export class ExampleTabFactory implements TabFactory { // 1
constructor(public router: Router) { }
get() {
const tabs: Tab[] = [];
if (this.router.url.match(/world/g)) { // 2
tabs.push({
path: 'world/awesome',
label: 'Awesome',
icon: 'angellist'
} as Tab);
}
return tabs; // 3
}
}By defining a Injectable() services which implements the TabFactory (1) you can define which tabs you want to show on which page. By using the Router service of Angular we check in this example if the URL of the route contains the name world (2) and only if this matches the tab labeled Awesome is returned (3). By hooking this into your provider definition of your module you make sure, that the get() function is checked on each route change:
@NgModule({
declarations: [
/* ... */
],
imports: [
BrowserAnimationsModule,
RouterModule.forRoot(),
ngRouterModule.forRoot([/* ... */], { enableTracing: false, useHash: true }),
CoreModule.forRoot()
],
providers: [
{ provide: HOOK_TABS, useClass: ExampleTabFactory, multi: true} // hook the ExampleTabFactory defined earlier
],
bootstrap: [BootstrapComponent]
})
export class AppModule { }Usually you use Content Projection within a route and Multi Provider if the context is shared across multiple routes or needs more complex logic to resolve the content. Examples: a title is just valid for one route -> use Content Projection. A tab should only be shown on specific routes under certain conditions -> use Multi Provider. The following hooks are currently supported:
HOOK_TABS: Allows to show tabs on certain conditions.HOOK_NAVIGATOR_NODES: Enables navigator nodes to be shown.HOOK_ACTION: Enables to define the global actions which should be shown or enabled on certain conditions.HOOK_ACTION_BAR: Enables to define local actions on a page.HOOK_BREADCRUMB: Can be used to show breadcrumbs in the header bar.HOOK_SEARCH: Allows to define the search to be shown or not.HOOK_COMPONENTS: A hook to add dynamic components to the UI (e.g. widgets).Services
A service is defined for most components of ngx-components. They can be used via the dependency injection concept of Angular, that means that these services can be injected in the constructor of a component and then add or remove certain UI elements. The following example shows how to use that concept with an alert:
constructor(private alert: AlertService) {
try {
// do something that might throw an exception
} catch(ex) {
this.alert.add({
text: 'Something bad happened!'
type: 'danger';
detailedData: ex;
} as Alert);
}
}Legacy plugins
If you are extending a default application (Cockpit, Device Management or Administration) you get a file called ng1.ts. These are so called plugins which haven't been migrated to Angular yet and are still using angular.js. You can add or remove these plugins to customize the application appearance like it has been done previously in a target file by the addImports: [] or removeImports: [] property. The following shows an example which removes the default import in the angular.js target file:
{
"name": "example",
"applications": [
{
"contextPath": "cockpit",
"addImports": [
"my-plugin/cockpit-home",
],
"removeImports": [
"core/cockpit-home"
]
}
]
} You get the same result in the new Angular framework by modifying the ng1.ts file of the cockpit app:
import '@c8y/ng1-modules/core';
// [...] more imports removed for readability
import '@c8y/ng1-modules/alarmAssets/cumulocity.json';
// import '@c8y/ng1-modules/cockpit-home/cumulocity.json'; // 1
import '@c8y/ng1-modules/deviceControlMessage/cumulocity.json';
import '@c8y/ng1-modules/deviceControlRelay/cumulocity.json';
// [...] more imports removed for readability
import 'my-plugin/cumulocity.json'; // 2 As you can see we simply removed the import of the original welcome screen plugin (1.) and replaced it by the custom implementation (2.). Note that all angular.js plugins need to have the /cumulocity.json addition to tell webpack that a legacy plugin is imported.
To use legacy plugins in your custom non-default application you need to set the upgrade flag in the package.json file and use the same import approach like described before:
"c8y": {
"application": {
"name": "myapp",
"contextPath": "myapp",
"key": "myapp-application-key",
"upgrade": true
}
}Also the module definition of your application must be changed to support these plugins:
import { NgModule } from '@angular/core';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { RouterModule as NgRouterModule } from '@angular/router';
import { UpgradeModule as NgUpgradeModule } from '@angular/upgrade/static';
import { CoreModule, RouterModule } from '@c8y/ngx-components';
import { UpgradeModule, HybridAppModule, UPGRADE_ROUTES } from '@c8y/ngx-components/upgrade';
import { AssetsNavigatorModule } from '@c8y/ngx-components/assets-navigator';
@NgModule({
imports: [
BrowserAnimationsModule,
RouterModule.forRoot(),
NgRouterModule.forRoot([
...UPGRADE_ROUTES,
], { enableTracing: false, useHash: true }),
CoreModule.forRoot(),
AssetsNavigatorModule,
NgUpgradeModule,
// Upgrade module must be the last
UpgradeModule
]
})
export class AppModule extends HybridAppModule {
constructor(protected upgrade: NgUpgradeModule) {
super();
}
}That will let your app start in a hybrid mode, which allows to use angular.js and Angular plugins/modules.
To determine which extension points are supported and which concept should be used for certain scenarios the following section gives an overview on all supported components and explains in which case they should be used.
The CommonModule exports the DataModule, an abstraction of the @c8y/client which allows to use the services of the client with the dependency injection system of Angular. So in any module in which the CommonModule or DataModule is imported you can use simple injection to access data of the platform:
import { Component } from '@angular/core';
import { AlarmService } from '@c8y/client'; // 1
@Component({selector: 'app-alerts', template: ''})
export class AlarmComponent {
constructor(private alarmService: AlarmService) {} // 2
async getAllAlarms() {
const alarms = await this.alarmService.list(); // 3
return alarms.data;
}
}For detailed information on all available services and on how to filter and select data refer to @c8y/client.