Update gets triggered on render with initialValues

Are you submitting a bug report or a feature request?

Not sure if it’s a bug or a if it works as intended

What is the current behavior?

Updates are triggered once when then the form is rendered, i.e. even though no changes have been made to the form values.

See https://codesandbox.io/s/0ml4k745x0

What is the expected behavior?

I would expect updates to be triggered only on updates, not by the initial values.

What’s your environment?

    "react": "^16.6.3",
    "react-dom": "^16.6.3",
    "react-final-form": "^4.0.2",
    "final-form": "^4.11.0",
    "final-form-calculate": "^1.3.0"

[nik-lampe]

Interesting. This does not happen, when you specify the field as a regex. And, it gets triggered, but it seems that the changes won’t be applied to the values.

Came across this, because I’m looking for a way to do a initial calculation with the initial values

[leonardopolly]

@cordial, I got to work around this by wrapping createDecorator function in my own really small decorator that returns the original decorator called with form as its argument. In the updates property you can now access form and check if it is pristine. If it is, simply return an empty object 😃

Instead of writing

const myDecorator = createDecorator({
  field: 'fieldA',
  updates: {
    b: (fieldAValue, allValues) => { 
      //your calculation 
    }
  }
});

you can write

const myDecorator = form => createDecorator({
  field: 'fieldA',
  updates: form.getState().pristine? {} : {
    b: (fieldAValue, allValues) => { 
      //your calculation 
    }
  }
})(form)