formRef getModel documentation

[simplecommerce]

Hi,

I noticed that the getModel method that is avaiable via formRef is not in your documentation.
I just thought maybe it should be, in my case I found it very useful as a method in order to get the updated model from outside the form, especially with the mode argument which allows me to get the transformed model.

[radekmie]

Hi @simplecommerce. While I agree that it's much better than simply accessing the props or state of the form, I'm still unsure whether or not we want to make it a part of the public API. Could you share your exact use case?

[simplecommerce]

@radekmie No problem, here are my current use cases.

In one case, I need to compare the saved value from my form in my database against the calculated value in my form.
Flow:

1. An amount is received from my database. (e.g.: Subtotal)
2. In my form's model, I do some specific calculations and the result is stored in a field. (Total)
3. This field is saved in my database.
4. When I go back to the form, the saved value is reloaded in the form. (Total)
5. If the amount that is received from my database has changed (Subtotal), then the calculated value (Total) will differ than what was stored initially.

So I have a useEffect on mount, that validates the saved Total vs the new calculated Total by using the getModel("submit").

In another case, I have some logic in the onChange method of the form.
I check for a specific field that is being changed, and then I also need to compare other values from the model itself, before applying my logic. So I use the getModel() to get that information.

For this case, I could've put the logic in each component, but since the logic was similar but just the field names changed, I didn't want to repeat my code/logic in each component and centralized it in the form's onChange method.

In another case, I have a text field that has a calculate button. When I click that button, I need to pull information from the model in order to apply the calculations needed. The reason I am using getModel here, is that my text field is already a custom component that uses useField internally and the calculate button is an adornment option that I am using (Material-UI) in order to add additional feature to it for a specific case.

Sorry if I am not too clear with my examples, but in my cases I just found it easier to implement when using your getModel method. (in my mind)

[radekmie]

I think these are completely valid use cases for this function. We'll discuss how to approach it.

[wadamek65]

Since we could not come up with an idea for a cleaner API for this, I think it would be best to document this with a note mentioning that this pattern should be avoided whenever possible.

[simplecommerce]

@wadamek65 what would be your suggestion in getting the internal model values of the form from the outside?

[wadamek65]

@simplecommerce As I've mentioned, we couldn't really come up with a better idea for a solution for this problem so what you did is probably optimal. But this (imperative) pattern IMO isn't very idiomatic to React and should be avoided if there is a better one available.

[radekmie]

Just to confirm what @wadamek65 said - there's no other API for that and we don't want to document the one that is there now. If we'll come up with one we think is better, it'll definitely get documented!

(If you have an idea for it, do let us know!)