React Flux - Return value from flux dispatcher / s

问题:

I am using the flux-pattern and the flux dispatcher. I need to return a value from 'TextStore' to an action after creating a new TextItem because I need to reference it in another store. Here is a very simple version of what I want to do:

// stores.ts
var TextStore = {
    add(){
        // here I want to return a new ID
        return createRandomID();
    }
    ...
}
var ModuleStore = {
    labelTextID; // refers to `id` on Text
    ...
}


// moduleactions.ts
...
import PageActions from './PageActions';
var ModuleActions = {
    add: function (module) {
        var textID = PageActions.add(); // here I need to get the ID of the newly create `Text`
        module.labelTextID = textID;
        Dispatcher.dispatch({
            action: 'ADD_MODULE',
            module: module
        })
    },
    ...
}

Now when I add a new Module via dispatching an action, I want to create a new Text as well and return its newly created ID from the store before.

The most obvious way would be to require the TextStore inside ModuleActions and call add() directly. Is that against the flux-pattern?

Is there any way to accomplish that, maybe with promises? Sending callbacks via the dispatcher to the store doesnt work, because I cannot dispatch while another dispatch is unfinished.

Would be great if you guys can help me!

回答1:

Calling the Store's method directly is an anti-pattern for Flux. If you directly call TextStore.add() then you are not following the

Action -> Dispatcher -> Store --> View --> Action cycle.

In flux, the data should always generate in the action. This makes more sense when the process of generation of data is aync. In your case you were able to get around this because generation of data is not async. You are directly generating the data in the TextStore and then worrying about how to return that value.

In your case generate the id in the action as you would have done if it was an async backend event, then pass that id down to the TextStore via dispatcher and after that also pass the same id to the ModuleStore via the dispatcher.

var ModuleActions = {
    add: function (module) {
        var textID = new Date().getTime(); // this is the CHANGE i added
        PageActions.add(textID); 
        module.labelTextID = textID;
        Dispatcher.dispatch({
            action: 'ADD_MODULE',
            module: module
        })
    }
}

You could also break this down into further smaller, more specific actions. I kept it as-is so I could highlight the one line you should change.

回答2:

Is there any way to accomplish that, maybe with promises? Sending callbacks via the dispatcher to the store doesnt work, because I cannot dispatch while another dispatch is unfinished.

You can have your async call PageActions.add(); before you dispatch the ModuleActions.add and pass the returned value as a parameter to ModuleActions.add