silverstripe-userforms/code/model/submissions/SubmittedForm.php

<?php
/**
 * Contents of an UserDefinedForm submission
 *
 * @package userforms
 */

class SubmittedForm extends DataObject {

	private static $has_one = array(
		"SubmittedBy" => "Member",
		"Parent" => "UserDefinedForm",
	);

	private static $has_many = array(
		"Values" => "SubmittedFormField"
	);

	private static $summary_fields = array(
		'ID',
		'Created'
	);

	/**
	 * Returns the value of a relation or, in the case of this form, the value
	 * of a given child {@link SubmittedFormField}
	 *
	 * @param string
	 *
	 * @return mixed
	 */
	public function relField($fieldName) {
		// default case
		if($value = parent::relField($fieldName)) {
			return $value;
		}

		// check values for a form field with the matching name.
		$formField = SubmittedFormField::get()->filter(array(
			'ParentID' => $this->ID,
			'Name' => $fieldName
		))->first();

		if($formField) {
			return $formField->getFormattedValue();
		}
	}

	/**
	 * @return FieldList
	 */
	public function getCMSFields() {

		$self = $this;

		$this->beforeUpdateCMSFields(function($fields) use ($self) {
			$fields->removeByName('Values');
			$fields->dataFieldByName('SubmittedByID')->setDisabled(true);

			$values = new GridField(
				'Values',
				'SubmittedFormField',
				$self->Values()->sort('Created', 'ASC')
			);

			$config = new GridFieldConfig();
			$config->addComponent(new GridFieldDataColumns());
			$config->addComponent(new GridFieldExportButton());
			$config->addComponent(new GridFieldPrintButton());
			$values->setConfig($config);

			$fields->addFieldToTab('Root.Main', $values);
		});

		$fields = parent::getCMSFields();

		return $fields;
	}

	/**
	 * @param Member
	 *
	 * @return boolean
	 */
	public function canCreate($member = null) {
		return $this->Parent()->canCreate();
	}

	/**
	 * @param Member
	 *
	 * @return boolean
	 */
	public function canView($member = null) {
		return $this->Parent()->canView();
	}

	/**
	 * @param Member
	 *
	 * @return boolean
	 */
	public function canEdit($member = null) {
		return $this->Parent()->canEdit();
	}

	/**
	 * @param Member
	 *
	 * @return boolean
	 */
	public function canDelete($member = null) {
		return $this->Parent()->canDelete();
	}

	/**
	 * Before we delete this form make sure we delete all the
	 * field values so that we don't leave old data round
	 *
	 * @return void
	 */
	protected function onBeforeDelete() {
		if($this->Values()) {
			foreach($this->Values() as $value) {
				$value->delete();
			}
		}

		parent::onBeforeDelete();
	}
}