form_props

form_props is a Rails form builder that outputs HTML props instead of tags. Now you can enjoy the power and convenience of Rails helpers in React!

By separting attributes from tags, form_props can offer greater flexbility than normal Rails form builders; allowing designers to stay longer in HTML land and more easily customize their form structure without needing to know Rails.

Caution

This project is in its early phases of development. Its interface, behavior, and name are likely to change drastically before a major version release.

Installation

Add to your Gemfile

gem "form_props"

and bundle install

Usage

form_props is designed to be used in a PropsTemplate template (it can work with jbuilder). For example in your new.json.props:

json.some_form do
  form_props(@post) do |f|
    f.text_field :title
    f.submit
  end
end

would output

{
  someForm: {
    props: {
      id: "create-post",
      action: "/posts/123",
      acceptCharset: "UTF-8",
      method: "post"
    },
    extras: {
      method: {
        name: "_method",
        type: "hidden",
        defaultValue: "patch",
        autoComplete: "off"
      },
      utf8: {
        name: "utf8",
        type: "hidden",
        defaultValue: "\u0026#x2713;",
        autoComplete: "off"
      }
      csrf: {
        name: "utf8",
        type: "authenticity_token",
        defaultValue: "SomeTOken!23$",
        autoComplete: "off"
      }
    },
    inputs: {
      title: {name: "post[title]", id: "post_title", type: "text", defaultValue: "hello"},
      submit: {type: "submit", value: "Update a Post"}
    }
  }
}

You can then proceed to use this output in React like so:

import React from 'react'

export default ({props, inputs, extras}) => {
  <form {...props}>
    {Object.values(extras).map((hiddenProps) => (<input {...hiddenProps} key={hiddenProps.name}/>))}

    <input {...inputs.title} />
    <label for={inputs.title.id}>Your Name</label>
    <button {...inputs.submit}>{inputs.submit.text}</button>
  </form>
}

Key format

By default, props_template automatically camelize(:lower) on all keys. All documentation here reflects that default. You can change that behavior if you wish.

Flexibility

form_props is only concerned about attributes, the designer can focus on tag structure and stay longer in HTML land. For example, you can decide to nest an input inside a label.

<label for={inputs.name.id}>
  Your Name
  <input {...inputs.name} type="text"/>
</label>

or not

<label for={inputs.name.id}>Your Name</label>
<input {...inputs.name} />

Custom Components

With form_props you can combine the comprehensiveness of Rails forms with your prefered React components:

For example:

json.some_form do
  form_props(@post) do |f|
    f.time_zone_select(:time_zone)
    ...
  end
end

Then use it the props your own components or a external component like react-select:

import React from 'react'
import Select from 'react-select';

export default (({props, inputs, extras})) => {
  return (
    <form {...props}>
      <Select
        {...inputs.timeZone}
        isMulti={inputs.timeZone.multiple}
      />
    </form>
  )
}

Error handling

form_props doesn't handle form errors, but you can easily add this functionality:

json.someForm do
  form_props(@post) do |f|
    f.text_field :title
  end

  json.errors @post.errors.to_hash(true)
end

then merge it later

<MyTextComponent {...someForm.inputs.title, error: ...someForm.errors.title}>

form_props

form_props shares most of same arguments as form_with. The differences are

1. remote and local options are removed.
2. You can change the name of the value keys generated by the form helpers from defaultValue to value, by using controlled: true. For example:

json.some_form do
  form_props(@post, controlled: true) do |f|
    f.text_field :title
  end
end

By default, the controlled option is false.

props Attributes that you can splat directly into your <form> element.

extras contain hidden input attributes that are created by form_props indirectly, for example, the csrf token. Its best to wrap this in a custom component that does the following. An Extra component is available

Object.values(extras).map((hiddenProps) => (<input {...hiddenProps} type="hidden"/>))}

Form Helpers

form_props provides its own version of the following Rails form helpers:

check_box                 file_field                submit
collection_check_boxes    grouped_collection_select tel_field
collection_helpers        hidden_field              text_area
collection_radio_buttons  month_field               text_field
collection_select         number_field              time_field
color_field               password_field            time_zone_select
date_field                radio_button              url_field
datetime_field            range_field               week_field
datetime_local_field      search_field              weekday_select
email_field               select

form_props is a fork of form_with, and the accompanying form builder inherits from ActionView::Helpers::FormBuilder.

Many of the helpers accept the same arguments and you can continue to rely on [Rails Guides for form helpers] for guidance, but as the goal of form_props is to focus on attributes instead of tags there are a few general differences across all helpers that would beneficial to know:

1. The form helper f.label do not exist. Helpers like the below that yields for label structure

f.collection_radio_buttons(:active, [true, false], :to_s, :to_s) do |b|
  b.label { b.radio_button + b.text }
end

no longer takes in blocks to do so.

2. defaultValues are not escaped. Instead, we lean on PropsTemplate to escape JSON and HTML entities.
3. defaultValue will not appear as a key if no value was set.
4. data-disable-with is removed on submit buttons.
5. data-remote is removed from form props.
6. For helpers selectively render hidden inputs, we passed the attribute to
7. f.select helpers does not render selected on options, instead it follows react caveats and renders on the input's value. For example:

{
  "type": "select",
  "name": "continent[countries]",
  "id": "continent_countries",
  "multiple": true,
  "defaultValue": ["Africa", "Europe"],
  "options": [
    {"value": "Africa", "label": "Africa"},
    {"value": "Europe", "label": "Europe"},
    {"value": "America", "label": "America", "disabled": true}
  ]
}

Unsupported helpers

form_props does not support:

label. We encourage you to use the tag directly in combination with other helpers. For example:

<label for={inputs.name.id} />

rich_text_area. We encourage you to use the f.text_area helper in combination with Trix wrapped in React, or TinyMCE's react component.

button. We encourage you to use the tag directly.

date_select, time_select, datetime_select. We encourage you to use other alternatives like react-date-picker in combination with other supported date field helpers.

Text helpers

text_field, email_field, tel_field, file_field, url_field, hidden_field, and the slight variations password_field, search_field, color_field has the same arguments as their Rails counterpart.

When used like so

form_props(model: @post) do |f|
  f.text_field(:title)
end

inputs.title would output

{
  "type": "text",
  "defaultValue": "Hello World",
  "name": "post[title]",
  "id": "post_title"
}

Date helpers

date_field, datetime_field, datetime_local_field, month_field, week_field has the same arguments as their Rails counterparts.

When used like so

form_props(model: @post) do |f|
  f.datetime_field(:created_at)
end

inputs.created_at would output

{
  "type": "datetime-local",
  "defaultValue": "2004-06-15T01:02:03",
  "name": "post[created_at]",
  "id": "post_created_at"
}

Number helpers

number_field, range_field has the same arguments as their Rails counterparts.

When used like so

@post.favs = 2

form_props(model: @post) do |f|
  f.range_field(:favs, in: 1...10)
end

inputs.favs would output

{
  "type": "range",
  "defaultValue": "2",
  "name": "post[favs]",
  "min": 1,
  "max": 9,
  "id": "post_favs"
}

Checkbox helper

check_box has the same arguments its Rails counterpart.

The original Rails check_box helper renders an unchecked value in a hidden input. While form_props doesn't generate the tags, the unchecked_value, and include_hidden can be passed to a React component to replicate that behavior. This repository has an example CheckBox component used in its test that you can refer to.

When used like so:

@post.admin = "on"

form_props(model: @post) do |f|
  f.check_box(:admin, {}, "on", "off")
end

inputs.admin would output

{
  "type": "checkbox",
  "defaultValue": "on",
  "uncheckedValue": "off",
  "name": "post[admin]",
  "id": "post_admin",
  "includeHidden": true
}

Radio helper

radio_button has the same arguments as its Rails counterpart. The radio button is unique

When used like so:

@post.admin = false

form_props(model: @post) do |f|
  f.radio_button(:admin, true)
  f.radio_button(:admin, false)
end

The keys on inputs are a combination of the name and value. So inputs.adminTrue would output:

{
  "type": "radio",
  "defaultValue": "true",
  "name": "post[admin]",
  "id": "post_admin_true"
}

and inputs.adminFalse would output

{
  "type": "radio",
  "defaultValue": "false",
  "name": "post[admin]",
  "id": "post_admin_false",
  "checked": true
}

Select helpers

select, weekday_select, [time_zone_select] mostly has the same arguments as its Rails counterpart. They key difference is that choices for select cannot be a string:

# BAD!!!

form_props(model: @post) do |f|
  f.select(:category, "<option><option/>", multiple: false)
end

# Good

form_props(model: @post) do |f|
  f.select(:category, [], multiple: false)
end

When used like so

@post.category = "lifestyle"

form_props(model: @post) do |f|
  f.select(:category, ["lifestyle", "programming", "spiritual"], {selected: "", disabled: "", prompt: "Choose one"}, {required: true})
end

inputs.category would output

{
  "type": "select",
  "required": true,
  "name": "post[category]",
  "id": "post_category",
  "defaultValue":"lifestyle",
  "options": [
    {"disabled": true, "value": "", "label": "Choose one"},
    {"value": "lifestyle", "label": "lifestyle"},
    {"value": "programming", "label": "programming"},
    {"value": "spiritual", "label": "spiritual"}
  ]
}

Of note:

1. Notice that we follow react caveats and put selected values on defaultValue. This rule does not apply to the disabled attribute on option.
2. When multiple: true, defaultValue is an array of values.
3. The key, defaultValue is only set if the value is in options. For example:

form_props(model: @post) do |f|
  f.select(:category, [])
end

would output in inputs.category:

{
  "type": "select",
  "name": "post[category]",
  "id": "post_category",
  "options": []
}

As the select helper renders nested options and includeHidden, a custom component is required to correctly render the tag structure. A reference Select component implementation is availble that is used in our tests.

The select helper can also output a grouped collection.

@post = Post.new
countries_by_continent = [
  ["<Africa>", [["<South Africa>", "<sa>"], ["Somalia", "so"]]],
  ["Europe", [["Denmark", "dk"], ["Ireland", "ie"]]]
]

form_props(model: @post) do |f|
  f.select(:category, countries_by_continent)
end

inputs.category would output:

{
  "type": "select",
  "name": "post[category]",
  "id": "post_category",
  "options": [
    {
      "label": "<Africa>", "options": [
        {"value": "<sa>", "label": "<South Africa>"},
        {"value": "so", "label": "Somalia"}
      ]
    },
    {
      "label": "Europe", "options": [
        {"value": "dk", "label": "Denmark"},
        {"value": "ie", "label": "Ireland"}
      ]
    }
  ]
}

Group collection select

group_collection_select has the same arguments its Rails counterpart.

Like select, you'll need combine this with a custom Select component. An example Select component is available.

When used like so:

@post = Post.new
@post.country = "dk"
label_proc = proc { |c| c.id }

continents = [
  Continent.new("<Africa>", [Country.new("<sa>", "<South Africa>"), Country.new("so", "Somalia")]),
  Continent.new("Europe", [Country.new("dk", "Denmark"), Country.new("ie", "Ireland")])
]

form_props(model: @post) do |f|
  f.grouped_collection_select(
    :country, continents, "countries", label_proc, "country_id", "country_name"
  )
end

inputs.country would output

{
  "name": "post[country]",
  "id": "post_country",
  "type": "select",
  "defaultValue": "dk",
  "options": [
    {
      "label":"<Africa>",
      "options": [
        {"value": "<sa>", "label": "<South Africa>"},
        {"value": "so", "label": "Somalia"}
      ]
    }, {
      "label": "Europe",
      "options": [
        {"value": "dk", "label": "Denmark"},
        {"value":"ie", "label": "Ireland"}
      ]
    }
  ]
}

Collection select

collection_select, collection_radio_buttons, and collection_check_boxes has the same arguments its Rails counterpart, but their output differs slightly.

collection_select follows the same output as f.select. When used like so:

dummy_posts = [
  Post.new(1, "<Abe> went home", "<Abe>", "To a little house", "shh!"),
  Post.new(2, "Babe went home", "Babe", "To a little house", "shh!"),
  Post.new(3, "Cabe went home", "Cabe", "To a little house", "shh!")
]


form_props(model: @post) do |f|
  f.collection_select(:author_name, dummy_posts, "author_name", "author_name")
end

inputs.authorName would output:

{
  "type": "select",
  "name": "post[author_name]",
  "id": "post_author_name",
  "defaultValue": "Babe",
  "options": [
    {"value": "<Abe>", "label": "<Abe>"},
    {"value": "Babe", "label": "Babe"},
    {"value": "Cabe", "label": "Cabe"}
  ]
}

collection_radio_buttons and collection_check_boxes usage is the same with their rails counterpart, and when used, would render:

{
  "collection": [
    {"name":"user[other_category_ids][]","type": "checkbox", "defaultValue": "1", "uncheckedValue":"","id":"user_category_ids_1","label": "Category 1"},
    {"name":"user[other_category_ids][]","type": "checkbox", "defaultValue": "2", "uncheckedValue":"","id":"user_category_ids_2","label": "Category 2"}
  ],
  "name": "user[other_category_ids][]",
  "includeHidden": true
}

Like select, you would need a custom component to render. An example implementation for CollectionCheckBoxes and CollectionRadioButtons are available.

jbuilder

form_props can work with jbuilder, but needs an extra call in the beginning of your template to FormProps.set to inject json. For example.

FormProps.set(json, self)

json.data do
  json.hello "world"

  json.form do
    form_props(model: User.new, url: "/") do |f|
      f.text_field(:email)
      f.submit
    end
  end
end

Special Thanks

Thanks to bootstrap_form documentation for inspiration.