owl/doc/reference/environment.md

🦉 Environment 🦉

An environment is an object which contains a QWeb instance. Whenever a root component is created, it is assigned an environment (see below for more info on this). This environment is then automatically given to each sub component (and accessible in the this.env property).

    Root
    /  \
   A    B

This way, all components share the same QWeb instance.

Note: some additional information about what should go into an environment can be found in the learning section.

Setting an environment

An Owl application needs an environment to be executed. The environment has an important key: the QWeb instance, which will render all templates.

Whenever a root component App is mounted, Owl will setup a valid environment by following the next steps:

• take the env object defined on App.env (if no env was explicitely setup, this will be return the empty env object defined on Component)
• if env.qweb is not set, then Owl will create a QWeb instance.

The correct way to customize an environment is to simply set it up on the root component class, before the first component is created:

App.env = {
    _t: myTranslateFunction,
    user: {...},
    services: {
        ...
    },
};
const app = new App();
app.mount(document.body);

It is also possible to simply share an environment between all root components, by simply doing this:

Component.env = myEnv; // will be the default env for all components