alfresco-ng2-components/docs/core/services/app-config.service.md

Title, Added, Status, Last reviewed

Title	Added	Status	Last reviewed
App Config service	v2.0.0	Active	2018-09-13

App Config service

Supports app configuration settings, stored server side.

Class members

Methods

• get(key: string, defaultValue?: )
  Gets the value of a named property.
  • key: string - Name of the property
  • defaultValue: - (Optional) Value to return if the key is not found
• getLocationHostname(): string
  Gets the location.hostname property.
  • Returns string - Value of the property
• getLocationPort(prefix: string = ""): string
  Gets the location.port property.
  • prefix: string - Text added before port value
  • Returns string - Port with prefix
• getLocationProtocol(): string
  Gets the location.protocol value.
  • Returns string - The location.protocol string
• load(): Promise<any>
  Loads the config file.
  • Returns Promise<any> - Notification when loading is complete
• loadWellKnown(hostIdp: string): Promise<OpenidConfiguration>
  Call the discovery API to fetch configuration
  • hostIdp: string -
  • Returns Promise<OpenidConfiguration> - Discovery configuration
• select(property: string): Observable<any>
  Requests notification of a property value when it is loaded.
  • property: string - The desired property value
  • Returns Observable<any> - Property value, when loaded

Details

The AppConfigService service provides support for loading and accessing global application configuration settings that you store on the server side in the form of a JSON file.

You may need this service when deploying your ADF-based application to production servers. There can be more than one server running web apps with different settings, like different addresses for Alfresco Content/Process services.

You may also use the service if there is a need to change global settings for all the clients.

The service is already pre-configured to look for the "app.config.json" file in the application root address. This allows you to deploy ADF-based web applications to multiple servers together with different settings files. You could use this, for example, to create separate development, staging, and production environments.

Example of the default settings file content:

app.config.json

{
    "ecmHost": "http://localhost:3000/ecm",
    "bpmHost": "http://localhost:3000/bpm",
    "application": {
        "name": "Alfresco"
    }
}

Note that the settings in the example above are the default ones supplied with the server. You can override the values in your custom app.config.json file if necessary.

Below is a simple example of using the AppConfigService in practice.

app.component.ts

import { AppConfigService } from '@alfresco/adf-core';

@Component({...})
export class AppComponent {

    constructor(appConfig: AppConfigService) {

        // get nested properties by the path
        console.log(appConfig.get('application.name'));

        // use generics for type safety 
        let version: number = appConfig.get<number>('version');
        console.log(version);
    }
}

Your custom components can also benefit from the AppConfigService. You can create an unlimited number of settings and optionally organize them as a nested JSON hierarchy.

Variable substitution in configuration strings

The AppConfigService supports a limited set of variable substitutions to greatly simplify certain scenarios.

{
    "ecmHost": "{protocol}//{hostname}:{port}/ecm",
    "bpmHost": "{protocol}//{hostname}:{port}/bpm",
    "application": {
        "name": "Alfresco"
    }
}

The supported variables are:

Variable name	Runtime value
protocol	location.protocol
hostname	location.hostname
port	location.port

App Config onLoad Stream

When the app config is loaded correctly, an onChange event is emitted with the whole set of app config properties. This comes in handy when a component needs to react to some property change or interact with the app config when it is finished loading:

    appConfig.onLoad.subscribe((appConfig) => {
        console.log(appConfig); //this is the representation of the app-config
    });

The select method lets you specify the name of a variable that should be set with the value of a property when the app config is loaded:

    appconfig : {
        logLevel : 'trace'
    }

    
    appConfig.select('logLevel').subscribe((logLevelValue) => {
        console.log(logLevelValue); //this will be 'trace';
    });

XMLHttpRequest.withCredentials

In the configuration file, you can enable XMLHttpRequest.withCredentials for @alfresco/js-api calls and PDF Viewer.

{
    "auth": {
      "withCredentials": true
    }
}