Collections are used for working with array of data, mostly used for relationships (OneToMany, ManyToMany).

It can be any type that is available in the package. Here are some examples:

<?php
use Kris\LaravelFormBuilder\Form;

class PostForm extends Form
{
    public function buildForm()
    {
        $this
            ->add('title', 'text')
            ->add('body', 'textarea')
            ->add('tags', 'collection', [
                'type' => 'text',
                'property' => 'name',    // Which property to use on the tags model for value, defualts to id
                'data' => [],            // Data is automatically bound from model, here we can override it
                'options' => [    // these are options for a single type
                    'label' => false,
                    'attr' => ['class' => 'tag']
                ]
            ]);
    }
}

And in controller:

<?php

class MainController extends Controller
{
    public function edit($id, FormBuilder $formBuilder)
    {
        $post = Post::findOrFail($id);
        // Post model contains this data
        // $post = [
        //     'id' => 1,
        //     'title' => 'lorem ipsum',
        //     'body' => 'dolor sit'
        //     'tags' => [
        //         ['id' => 1, 'name' => 'work', 'desc' => 'For work'],
        //         ['id' => 2, 'name' => 'personal', 'desc' => 'For personal usage']
        //     ]
        // ]

        // Collection field type will automatically pull tags data from the model,
        // If we want to override the data, we can pass `data` option to the field

        $form = $formBuilder->create('App\Forms\PostForm', [
            'model' => $post
        ]);

        return view('posts.edit', compact('form'));
    }
}

Then the view will contain:

<form method="POST" action="/post/1">
    <div class="form-group">
        <label for="title" class="control-label">Title</label>
        <input type="text" id="title" class="form-control" name="title" value="lorem ipsum">
    </div>
    <div class="form-group">
        <label for="body" class="control-label">Body</label>
        <textarea id="body" name="body">dolor sit</textarea>
    </div>
    <div class="form-group">
        <label for="tags" class="control-label">Tags</label>
        <div class="form-group">
            <input type="text" id="tags[0]" class="tag" name="tags[0]" value="work">
        </div>
        <div class="form-group">
            <input type="text" id="tags[1]" class="tag" name="tags[1]" value="personal">
        </div>
    </div>
</form>

Collection of child forms

Child forms can be also used in a collection:


<?php
use Kris\LaravelFormBuilder\Form;

class TagsForm extends Form
{
    public function buildForm()
    {
        $this
            ->add('name', 'text')
            ->add('desc', 'textarea');
    }
}

class PostForm extends Form
{
    public function buildForm()
    {
        $this
            ->add('title', 'text')
            ->add('body', 'textarea')
            ->add('tags', 'collection', [
                'type' => 'form',
                'options' => [    // these are options for a single type
                    'class' => 'App\Forms\TagsForm'
                    'label' => false,
                ]
            ]);
    }
}

And with same controller setup as above, we get this:

<form method="POST" action="/post/1">
    <div class="form-group">
        <label for="title" class="control-label">Title</label>
        <input type="text" id="title" class="form-control" name="title" value="lorem ipsum">
    </div>
    <div class="form-group">
        <label for="body" class="control-label">Body</label>
        <textarea id="body" name="body" class="form-control">dolor sit</textarea>
    </div>
    <div class="form-group">
        <label for="tags" class="control-label">Tags</label>
        <div class="form-group">
            <div class="form-group">
                <label for="tags[0][name]">Name</label>
                <input type="text" id="tags[0][name]" class="form-control" name="tags[0][name]" value="work">
            </div>
            <div class="form-group">
                <label for="tags[0][desc]">Desc</label>
                <textarea id="tags[0][desc]" name="tags[0][desc]" class="form-control">For work</textarea>
            </div>
        </div>
        <div class="form-group">
            <div class="form-group">
                <label for="tags[1][name]">Name</label>
                <input type="text" id="tags[1][name]" class="form-control" name="tags[1][name]" value="personal">
            </div>
            <div class="form-group">
                <label for="tags[1][desc]">Desc</label>
                <textarea id="tags[1][desc]" name="tags[1][desc]" class="form-control">For personal usage</textarea>
            </div>
        </div>
    </div>

Prototype

If you need to dynamically generate HTML for additional elements in the collection, you can use prototype() method on the form field. Let’s use example above:

@extends('app')

@section('content')
    {!! form_start($form) !!}
    <div class="collection-container" data-prototype="{{ form_row($form->tags->prototype()) }}"> // Use {{ }} here to escape html
        {!! form_row($form->tags) !!}
    </div>
    {!! form_end($form) !!}
    <button type="button" class="add-to-collection">Add to collection</button>
    <script src="https://code.jquery.com/jquery-2.1.3.min.js"></script>
    <script>
        $(document).ready(function() {
            $('.add-to-collection').on('click', function(e) {
                e.preventDefault();
                var container = $('.collection-container');
                var count = container.children().length;
                var proto = container.data('prototype').replace(/__NAME__/g, count);
                container.append(proto);
            });
        });
    </script>
@endsection

data-prototype will contain:

<div class="form-group">
    <div class="form-group">
        <label for="tags[__NAME__][name]">Name</label>
        <input type="text" id="tags[__NAME__][name]" class="form-control" name="tags[__NAME__][name]">
    </div>
    <div class="form-group">
        <label for="tags[__NAME__][desc]">Desc</label>
        <textarea id="tags[__NAME__][desc]" class="form-control" name="tags[__NAME__][desc]"></textarea>
    </div>
</div>

And clicking on the button .add-to-collection will automatically generate proper html from the prototype.

Prototype can be configured in the form class:

use Kris\LaravelFormBuilder\Form;

class PostForm extends Form
{
    public function buildForm()
    {
        $this
            ->add('title', 'text')
            ->add('body', 'textarea')
            ->add('tags', 'collection', [
                'type' => 'text',
                'property' => 'name',
                'prototype' => true,            // Should prototype be generated. Default: true
                'prototype_name' => '__NAME__' // Value used for replacing when generating new elements from prototype, default: __NAME__
                'options' => [
                    'label' => false,
                    'attr' => ['class' => 'tag']
                ]
            ]);
    }
}

Options

Beside inherited, there are some additional options available:

  • type (String) (Default: null) - Type of the collection item
  • options (Array) (Default: ['is_child' => true]) - Options that will be used for the collection item
  • data (Array) (Default: []) - This is the value for the collection
  • property (String) (Default: id) - Property to be used when pulling data from model
  • prototype (Boolean) (Default: true) - Should prototype be generated
  • prototype_name (String) (Default: __NAME__) - Namespace in the prototype that is generated
  • empty_row (Boolean) (Default: true) - Add an empty row if no data provided
  • prefer_input (Boolean) (Default: false) - Uses POST input items for validation instead of configured model data items
  • empty_model (Closure) (Default: null) - (Only for type = form!) Use the result of this function for model in empty row, prototype, and new rows during validation. This ensures all child forms will always have a real model als $this->model, instead of an array of the parent model.
    Example: 'empty_model' => fn() => new Tag().

Validated collection items

The POST request only validates items that it knows from the configured model. If the GET request (form display) builds a form with data with 4 items, and the POST request (form validation) builds a form without data, only 1 collection item will be accepted and validated, because the form doesn’t know there are 4.

Always build your form in POST exactly like you built it in GET! Same model, same data, same buttons etc.

Some forms let the user add more rows with Javascript (the prototype). In that case, you should set prefer_input = true, because the POST data will contain items unknown to the built form. In most cases, that is not necessary and not smart.

Simple example of bad and good POST action:

// GET request: show form with all items
public function edit(Post $post, FormBuilder $formBuilder)
    $form = $formBuilder->create('App\Forms\PostForm', [
        'model' => $post
    ]);
}

// BAD
public function store(Post $post, FormBuilder $formBuilder)
    // BAD: Form built without data!
    $form = $formBuilder->create('App\Forms\PostForm');
    $form->redirectIfNotValid();
    
    // BAD RESULT: only 1 collection item
    $values = $form->getFieldValues();
}

// GOOD
public function store(Post $post, FormBuilder $formBuilder)
    // GOOD: Form built exactly like in edit()
    $form = $formBuilder->create('App\Forms\PostForm', [
        'model' => $post
    ]);
    $form->redirectIfNotValid();
    
    // GOOD RESULT: all collection items, exactly like in the form HTML in edit()
    $values = $form->getFieldValues();
}