silverstripe-userforms/code/model/EditableCustomRule.php

<?php

/**
 * A custom rule for showing / hiding an EditableFormField
 * based the value of another EditableFormField.
 *
 * @method EditableFormField Parent()
 * @package userforms
 *
 * @property string Display
 * @property string ConditionOption
 * @property string FieldValue
 */
class EditableCustomRule extends DataObject
{

    private static $condition_options = array(
        "IsBlank" => "Is blank",
        "IsNotBlank" => "Is not blank",
        "HasValue" => "Equals",
        "ValueNot" => "Doesn't equal",
        "ValueLessThan" => "Less than",
        "ValueLessThanEqual" => "Less than or equal",
        "ValueGreaterThan" => "Greater than",
        "ValueGreaterThanEqual" => "Greater than or equal"
    );

    private static $db = array(
        'Display' => 'Enum("Show,Hide")',
        'ConditionOption' => 'Enum("IsBlank,IsNotBlank,HasValue,ValueNot,ValueLessThan,ValueLessThanEqual,ValueGreaterThan,ValueGreaterThanEqual")',
        'FieldValue' => 'Varchar(255)'
    );

    private static $has_one = array(
        'Parent' => 'EditableFormField',
        'ConditionField' => 'EditableFormField'
    );

    /**
     * Built in extensions required
     *
     * @config
     * @var array
     */
    private static $extensions = array(
        "Versioned('Stage', 'Live')"
    );

    /**
     * Publish this custom rule to the live site
     *
     * Wrapper for the {@link Versioned} publish function
     */
    public function doPublish($fromStage, $toStage, $createNewVersion = false)
    {
        $this->publish($fromStage, $toStage, $createNewVersion);
    }

    /**
     * Delete this custom rule from a given stage
     *
     * Wrapper for the {@link Versioned} deleteFromStage function
     */
    public function doDeleteFromStage($stage)
    {
        $this->deleteFromStage($stage);
    }


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

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

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

    /**
     * Return whether a user can create an object of this type
     *
     * @param Member $member
     * @param array $context Virtual parameter to allow context to be passed in to check
     * @return bool
     */
    public function canCreate($member = null)
    {
        // Check parent page
        $parent = $this->getCanCreateContext(func_get_args());
        if ($parent) {
            return $parent->canEdit($member);
        }

        // Fall back to secure admin permissions
        return parent::canCreate($member);
    }

    /**
     * Helper method to check the parent for this object
     *
     * @param array $args List of arguments passed to canCreate
     * @return DataObject Some parent dataobject to inherit permissions from
     */
    protected function getCanCreateContext($args)
    {
        // Inspect second parameter to canCreate for a 'Parent' context
        if (isset($args[1]['Parent'])) {
            return $args[1]['Parent'];
        }
        // Hack in currently edited page if context is missing
        if (Controller::has_curr() && Controller::curr() instanceof CMSMain) {
            return Controller::curr()->currentPage();
        }

        // No page being edited
        return null;
    }

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

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

    /**
     * Substitutes configured rule logic with it's JS equivalents and returns them as array elements
     * @return array
     */
    public function buildExpression()
    {
        /** @var EditableFormField $formFieldWatch */
        $formFieldWatch = $this->ConditionField();
        //Encapsulated the action to the object
        $action = $formFieldWatch->getJsEventHandler();

        // is this field a special option field
        $checkboxField = $formFieldWatch->isCheckBoxField();
        $radioField = $formFieldWatch->isRadioField();
        $target = sprintf('$("%s")', $formFieldWatch->getSelectorFieldOnly());
        $fieldValue = Convert::raw2js($this->FieldValue);

        $conditionOptions = array(
            'ValueLessThan'         => '<',
            'ValueLessThanEqual'    => '<=',
            'ValueGreaterThan'      => '>',
            'ValueGreaterThanEqual' => '>='
        );
        // and what should we evaluate
        switch ($this->ConditionOption) {
            case 'IsNotBlank':
            case 'IsBlank':
                $expression = ($checkboxField || $radioField) ? "!{$target}.is(\":checked\")" : "{$target}.val() == ''";
                if ($this->ConditionOption == 'IsNotBlank') {
                    //Negate
                    $expression = "!({$expression})";
                }
                break;
            case 'HasValue':
            case 'ValueNot':
                if ($checkboxField) {
                    if ($formFieldWatch->isCheckBoxGroupField()) {
                        $expression = sprintf(
                            "$.inArray('%s', %s.filter(':checked').map(function(){ return $(this).val();}).get()) > -1",
                            $fieldValue,
                            $target
                        );
                    } else {
                        $expression = "{$target}.prop('checked')";
                    }
                } elseif ($radioField) {
                    // We cannot simply get the value of the radio group, we need to find the checked option first.
                    $expression = sprintf(
                        '%s.closest(".field, .control-group").find("input:checked").val() == "%s"',
                        $target,
                        $fieldValue
                    );
                } else {
                    $expression = sprintf('%s.val() == "%s"', $target, $fieldValue);
                }

                if ($this->ConditionOption == 'ValueNot') {
                    //Negate
                    $expression = "!({$expression})";
                }
                break;
            case 'ValueLessThan':
            case 'ValueLessThanEqual':
            case 'ValueGreaterThan':
            case 'ValueGreaterThanEqual':
                $expression = sprintf(
                    '%s.val() %s parseFloat("%s")',
                    $target,
                    $conditionOptions[$this->ConditionOption],
                    $fieldValue
                );
                break;
            default:
                throw new LogicException("Unhandled rule {$this->ConditionOption}");
                break;
        }

        $result = array(
            'operation' => $expression,
            'event'     => $action,
        );

        return $result;
    }

    /**
     * Returns the opposite visibility function for the value of the initial visibility field, e.g. show/hide. This
     * will toggle the "hide" class either way, which is handled by CSS.
     *
     * @param string $text
     * @return string
     */
    public function toggleDisplayText($text)
    {
        return (strtolower($text) === 'hide') ? 'removeClass("hide")' : 'addClass("hide")';
    }
}