documentation/wowl_markdown_doc/services

Services

Overview

The Odoo web client is organized in components. It is common for a component to have a need to perform tasks or obtain some information outside of itself.

For example:

• performing an RPC
• displaying a notification
• asking the web client to change the current action/view
• ...

These kind of features are represented in the web client under the name service. A service is basically a piece of code that is started with the web client, and available to the interface (and to other services).

List of all services

Service	Purpose
action_manager	perform actions following user interactions
command	manage commands
crash_manager	listen errors and open error dialogs
dialog_manager	open dialogs
hotkey	manage all keyboard shortcuts in a single place
menus	keep track of all menu items (app and submenus)
model	interact with (python) models
notifications	display a notification (or error)
popover	add/remove popover
router	manage the url
rpc	perform a RPC (in other word, call the server)
title	allow to read/modify the document title
ui	miscellaneous ui features: active element, block/unblock
user	keep track of user main properties (lang, ...) and context
view_manager	load (and keep in cache) views information

Defining a service

A service needs to follow the following interface:

export interface Service<T = any> {
    dependencies?: string[];
    deploy: (env: OdooEnv, odoo: Odoo) => Promise<T> | T;
}

It may define some dependencies. In that case, the dependent services will be started first, and ready when the current service is started.

The deploy method is the most important: the return value of the deploy method will be the value of the service. This method can be asynchronous, in which case the value of the service will be the result of that promise.

Some services do not export any value. They may just do their work without a need to be directly called by other code. In that case, their value will be set to null in env.services.

Once a service is defined, it needs then to be registered to the serviceRegistry, to make sure it is properly deployed when the application is started.

serviceRegistry.add(myService.name, myService);

For example, imagine that we want to provide a service that manage a counter. It could be defined like this:

const counterService = {
    start(env) {
        let value = 0;
        return {
            getValue() {
                return value;
            },
            increment() {
                value++;
            }
        };
    }
};
serviceRegistry.add("counter", counterService);

The services listed above are deployed before the web client is mounted but it is allowed to add a service to the serviceRegistry after that moment. It will be automatically deployed.

Using a service

To use a service, a component needs to call the useService hook. This will return a reference to the service value, that can then be used by the component.

For example:

class MyComponent extends Component {
    rpc = useService('rpc');

    async willStart() {
        this.someValue = await this.rpc(...);
    }
}

Note: If the value of the service is a function (for example, like the rpc service), then the useService hook will bind it to the current component. This means that the code for the service can actually access the component reference.

A service that depends on other services (and having properly declared its dependencies) should use the other services by accessing them directly through the environment. For example, the service action_manager uses the service rpc in that way:

action = await env.services.rpc(...);