[RFC] useStatedBean with scope

[foreleven]

useStatedBean(Model) will find the model from the provider in the context, and will report an error if it does not exist. This feels unreasonable. It should be possible to temporarily create an instance of the Model whose lifecycle is consistent with the current component.

useStatedBean(Model, Scope?)

proposed scopes:

• Default: if existed in Context then Request
• Request: temporarily create an instance whose lifecycle is consistent with the current component.
• Context: find from the provider in the context

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[JounQin]

temporarily create an instance

How will you implement it, If the Model has other dependencies?

It it doesn't have any dependence, why not just useState(() => new Model())

So I think we should still resolve Model via DI, but we need find a way to register Models dynamicly.

[foreleven]

So I think we should still resolve Model via DI, but we need find a way to register Models dynamicly.

totally agree.

Currently, StatedBeanContainer caches the instance retrieved from the BeanFactory, and then useStatedBean got the cached object from the container in the context.

Now, how to create the container in useStatedBean when with the Request scope?

temporarily store the container with useState

interface UseStatedBeanOptions {
  dependentFields?: Array<string | symbol>;
  scope?: Scope
}

export function useStatedBean<T extends ClassType>(
  type: T,
  options?: UseStatedBeanOptions,
): InstanceType<T> {
  useState(() => {
    let container
    if (options.scope === Scope.Request) {
       container = new StatedBeanContainer(...);
    } else {
       // get container from context
    }
    return container;
   });
   ...  
}