How to bind mobx-react-form with mobx-state-tree store - mobx

Question

I have a form with three fields A, B and C. I am using mobx-react-form to handle the fields because it comes with onChange updates and validation baked in. I have set this up and it's working fine when I log out the values.
const View = inject('store')(observer(({ title }: Props) => {
return (
<div>
<form onSubmit={form.onSubmit}>
<label htmlFor={form.$('A').id}>
{form.$('A').label}
</label>
<input {...form.$('A').bind()} />
<label htmlFor={form.$('B').id}>
{form.$('B').label}
</label>
<input {...form.$('B').bind()} />
<label htmlFor={form.$('C').id}>
{form.$('C').label}
</label>
<input {...form.$('C').bind()} />
<button type="submit" onClick={form.onSubmit}>
Submit
</button>
</form>
</div>
);
}));
I will use the values from fields A, B and C to calculate additional values D and E which will appear in the app.
For state management, I am using mobx-state-tree to create the store.
export const Store = types.model('Store',
{
A: types.maybeNull(types.number),
B: types.maybeNull(types.number),
C: types.maybeNull(types.number),
D: types.maybeNull(types.number),
E: types.maybeNull(types.number),
})
.views(self => {
return {
getD: () => self.D,
getE: () => self.E
};
})
.actions(self => {
return {
setD: (A, B) => self.D = A + B,
setE: (B, C) => self.E = C - B,
resetStore: () => {
self.A = defaultState.A;
self.B = defaultState.B;
self.C = defaultState.C;
self.D = defaultState.D;
self.E = defaultState.E;
},
};
});
How can I bind the mobx-react-form fields A, B and C to corresponding values in the store so they update on change?

Answer 1

Well,
first of all,
I want you to notice , you are trying to connect 2 different state managers .
I like mobx-recat-form very much ! but you should consider that it
manages the state for you automatically .
You can bind yourself to onChange, and update D,E accordingly .
For Example:
<input onChange={e => {
form.$('B').set(e.target.value);
// handle D,E according to value
}} />
this is the most "direct" way to deal with it.
if you want to solve it in more "mobx" way ,
Do something likes this:
form.$('B')
.observe(({ form, field, change }) => {
// deal with D,E according to values
});
For further information I would take a look into:
https://foxhound87.github.io/mobx-react-form/docs/extra/mobx-events.html
And I would suggest to stick with this library(mobx-react-form) for controlling
the forms , and with direct hooks(1 st example) or by observing the form propagate changes to other values in other stores .