Add TextArrayInput to edit arrays of strings

[fzaninotto]

Problem

Our various array input components don't support the simple case of editing an array of strings with no choices.

Solution

2 possibilities:

1. Tweak the AutocompleteArrayInput to support simple addition with freeSolo. This is not possible because this input heavily relies on suggestions, and can't take a value outside of its choices. Even the onCreate support uses a special choice.
2. Implement a new, simpler component based on MUI's <Autocomplete> component.

I tried 1. but failed, so I went for 2.

DX

import { Create, SimpleForm, TextArrayInput, TextInput } from 'react-admin';

export const EmailCreate = () => (
    <Create>
        <SimpleForm>
            <TextArrayInput source="to" />
            <TextInput source="subject" />
            <TextInput source="body" multiline minRows={5} />
        </SimpleForm>
    </Create>
);

TextArrayInput.mp4

How To Test

Launch the storybook and check out the ra-ui-materialui/inputs/TextArrayInput stories at http://localhost:9010/?path=/story/ra-ui-materialui-input-textarrayinput--basic.

To Do

• Add component
• Add stories
• Add tests
• Add Documentation
• Reference it in other doc pages to make it discoverable

[fzaninotto]

Review applied