Component initialisation

[hchockarprasad]

Component init method doesn’t seems to be triggered…Is this a bug or should we need to call manually..If so where would be the best place to call manually?

[ivanceras]

@hchockarprasad, You have to manually call your Component's init function from your Application. Just like update in Component is also wired through your Application's update function. I haven't included a simplified example for this use-case, since I'm still stabilizing the method signatures of this init function in the Application and in the Component. However, A more advance usage is demonstrated here in the ultron editor, which I also wrote.

From the App's init function

    fn init(&mut self) -> Cmd<Self, Msg> {
        Cmd::batch([
            Cmd::new(|program| {
                program.add_window_event_listeners(vec![
                    on_mousemove(|me| Msg::WebEditorMsg(web_editor::Msg::Mousemove(me))),
                    on_mousedown(|me| Msg::WebEditorMsg(web_editor::Msg::Mousedown(me))),
                    on_mouseup(|me| Msg::WebEditorMsg(web_editor::Msg::Mouseup(me))),
                ])
            }),
            Cmd::from(self.web_editor.init().localize(Msg::WebEditorMsg)),
        ])
    }

It calls into the init function of the WebEditor Component, which also then calls to init function of its sub components.

In summary, Application is the only interface where the init function is called automatically, and it's up for you to wire its components and sub-components. The Program object only expects to be passed with an Application object. The Component is there for Composability and Convenience, to be used by your App. The program has no knowledge about Components.