formobx

A library for removing a lot of boilerplate from forms with Mobx. Inspired by redux-form and following a similar API, but using MobX for state management.

Written with typescript and built into plain JS. All examples can be ported to Javascript by removing any type information that may be present.

Work in progress - for full usage, look at the example projects.

Basic Usage:

// A basic input field component
import { field } from 'formobx';

interface MyFieldProps {
  type: string;
}

const MyField = field<MyFieldProps>(
  ({ field, type, name }) => (
    <div>
      <label>{name}: </label>
      <input
        {...field.asProps}
        type={type}
      />
    </div>
  )
);

// Make a formobx wrapper for your form
import { form } from 'formobx';

interface MyFormProps {
  title: string;
}

const MyFormWrapper = form<MyFormProps>({
  initialValues: {
    email: 'a@b.com'
  },
  onSubmit: makeLoginRequest
})

// Wrap your form component with it
const MyForm = MyFormWrapper(
  ({ form, onSubmit, title }) => (
    <form onSubmit={onSubmit}>
      <h1>{title}</h1>
      <MyField name="email" type="text" />
      <MyField name="password" type="password" />
      <button type="submit" disabled={form.submitting}>
        Log In
      </button>
    </form>
  )
);

// render the form
const App = () => (
  <MyForm title='Hello Formobx' />
);

Formobx uses the structure of your form to build a backing object. Arrays and complex objects are supported by using the ArrayField and ObjectField classes.

Docs

Stores

Stores are the backing objects behind fields which hold their data. This includes their values and errors, and any other information that may need to be tracked.

Shared properties for all stores:

• parent - get the parent store for this field
• value - get the value of this field
• errors - get the errors on this field
• clearErrors() - clear the errors for this field
• setErrors(errors) - set the errors for this field. Should be shaped according to children with each end value being an array of strings.

FieldStore

• asProps - returns an object with the properties onChange and value set for use with regular input fields
• setValue(val) - set the value for the field

ArrayStore

ObjectStore

FormStore

• submitting - a boolean representing whether this form is currently being submitted
• setSubmitting(submitting) - set the submitting property for the form

Factories

Factories are functions which take a React component and return a new wrapped version of the component which receives some additional props. Components created using these factories must be rendered with a name (or names) prop unless it is rendered inside an ArrayField. This name determines the key the value of this field will be under in the backing object for the form.

field

Added props: name (string), field (FieldStore)

multiField

Added props: names (string[]), fields (Object with FieldStore values)

meta

The meta factory passes the field representing the parent field to the wrapped component, allowing you to display errors for array and object fields, for example.

Added props: field (ArrayStore | ObjectStore | FormStore)

form

The form factory is special in that it returns another factory to wrap your component with. This is so you can pass in additional options for configuring the form.

• initialValues - an object shaped like the backing form object where each value is the starting value of the field.
• onSubmit(event, ...otherArgs) - a function which receives the form object and any other args you pass through when calling the onSubmit function passed as a prop to the wrapped component.

Added props: form (FormStore), onSubmit ((event, ...otherArgs) => void)

Components

ArrayField

React component representing an array in the form. Any components created with the factories above will be registered to the array if they are rendered inside it at any level of nesting. Their ordering in the array will be the same as that of the markup. Immediate children of the ArrayField do not need a name to be specified.

ObjectField

React component representing an object in the form. Any components created with the factories above will be registered to the object if they are rendered inside it at any level of nesting. They will be placed under the key given by their name prop.