FormKit allows you to set `@format` on a field which will set the width
of the wrapping container of the control. However, title and
descriptions are out of this container. FormKit will now by default
applies the same format to title and description.
You can override this behavior by using `@titleFormat` and
`@descriptionFormat`.
Form Kit is our new form library/framework for unifying the way forms look across Discourse. The admin config area for the /about page is a new form that isn't currently used, so it makes sense for it to be one of the first forms to be migrated to Form Kit to test the library.
Co-authored-by: Joffrey JAFFEUX <j.jaffeux@gmail.com>
This PR introduces FormKit, a component-based form library designed to simplify form creation and management. This library provides a single `Form` component, various field components, controls, validation mechanisms, and customization options. Additionally, it includes helpers to facilitate testing and writing specifications for forms.
1. **Form Component**:
- The main component that encapsulates form logic and structure.
- Yields various utilities like `Field`, `Submit`, `Alert`, etc.
**Example Usage**:
```gjs
import Form from "discourse/form";
<template>
<Form as |form|>
<form.Field
@name="username"
@title="Username"
@validation="required"
as |field|
>
<field.Input />
</form.Field>
<form.Field @name="age" @title="Age" as |field|>
<field.Input @type="number" />
</form.Field>
<form.Submit />
</Form>
</template>
```
2. **Validation**:
- Built-in validation rules such as `required`, `number`, `length`, and `url`.
- Custom validation callbacks for more complex validation logic.
**Example Usage**:
```javascript
validateUsername(name, value, data, { addError }) {
if (data.bar / 2 === value) {
addError(name, "That's not how maths work.");
}
}
```
```hbs
<form.Field @name="username" @validate={{this.validateUsername}} />
```
3. **Customization**:
- Plugin outlets for extending form functionality.
- Styling capabilities through propagated attributes.
- Custom controls with properties provided by `form` and `field`.
**Example Usage**:
```hbs
<Form class="my-form" as |form|>
<form.Field class="my-field" as |field|>
<MyCustomControl id={{field.id}} @onChange={{field.set}} />
</form.Field>
</Form>
```
4. **Helpers for Testing**:
- Test assertions for form and field validation.
**Example usage**:
```javascript
assert.form().hasErrors("the form shows errors");
assert.form().field("foo").hasValue("bar", "user has set the value");
```
- Helper for interacting with he form
**Example usage**:
```javascript
await formKit().field("foo").fillIn("bar");
```
5. **Page Object for System Specs**:
- Page objects for interacting with forms in system specs.
- Methods for submitting forms, checking alerts, and interacting with fields.
**Example Usage**:
```ruby
form = PageObjects::Components::FormKit.new(".my-form")
form.submit
expect(form).to have_an_alert("message")
```
**Field Interactions**:
```ruby
field = form.field("foo")
expect(field).to have_value("bar")
field.fill_in("bar")
```
6. **Collections handling**:
- A specific component to handle array of objects
**Example Usage**:
```gjs
<Form @data={{hash foo=(array (hash bar=1) (hash bar=2))}} as |form|>
<form.Collection @name="foo" as |collection|>
<collection.Field @name="bar" @title="Bar" as |field|>
<field.Input />
</collection.Field>
</form.Collection>
</Form>
```
