README

Small module to limit number of records that can be added to a SilverStripe GridField.

Important - this module does not prevent records being added at an ORM/code-level in any way.

Instead, it manipulates the GridField UI to allow developers to hide controls like GridFieldAddNewButton once a set limit is reached, preventing CMS users from adding more records via that grid field.

• It hides GridFieldAddNewButton, GridFieldAddExistingAutocompleter and other GridFieldComponents you define, if the limit is reached
• Optionally, if limit has been reached, a message is also presented to the user notifying them of this

Requirements

SilverStripe 5+

Installation

composer require fromholdio/silverstripe-gridfield-limiter

Detail

• Add GridFieldLimiter to your GridFieldConfig, and define a target fragment (defaults to before)
• It will create two new target fragments, limiter-before-left and limiter-before-right (before comes from the defined target fragment)
• You can now fill these two fragments with grid field components, like a GridFieldAddNewButton on the left and a GridFieldAddExistingAutocompleter on the right, which will all be hidden (via css) from the CMS user once the grid field reaches its row limit
• If enabled, a message will be displayed to the user telling them to remove an item before they add a new one

Per the note above, this does not in anyway validate the number of objects in a relationship or prevent an object being added - it's just a cheeky way to implement a limit for CMS users managing a grid field.

Under-limit screenshot

Limit-reached screenshot

Usage example

We have a standard GridField using a GridFieldConfig_RecordEditor and will add a limit to it.

$gridField = GridField::create(
    'Widgets',
    'Widgets',
    $this->Widgets(),
    $gridConfig = GridFieldConfig_RecordEditor::create()
);

Remove the GridFieldAddNewButton in preparation to add one within our GridFieldLimiter:

$gridConfig->removeComponentsByType(GridFieldAddNewButton::class);

Add the GridFieldLimiter

$limit = 4;  // We want to limit this gridfield to 4 objects
$targetFragment = 'before' // Set gridfield target fragment value
$showLimitReachedMessage = true // We want to show the user a note when the limit is reached

$gridConfig->addComponent(
    new GridFieldLimiter($limit, $targetFragment, $showLimitReachedMessage)
);

Add a GridFieldAddNewButton (and/or any other components) you would like displayed while under limit but hidden when limit is reached, using the limiter target fragment.

$gridConfig->addComponent(
    new GridFieldAddNewButton('limiter-before-left')
);

That should work!

$fields->addFieldToTab('Root.Testing', $gridField);