Source of file BlogObject.php

<?php

namespace SilverStripe\Blog\Model;

use SilverStripe\Control\Controller;

use SilverStripe\Forms\FieldList;

use SilverStripe\Forms\Tab;

use SilverStripe\Forms\TabSet;

use SilverStripe\Forms\TextField;

use SilverStripe\ORM\DataList;

use SilverStripe\ORM\ValidationResult;

use SilverStripe\Security\Member;

use SilverStripe\Security\Permission;

use SilverStripe\View\Parsers\URLSegmentFilter;

/**

 * An object shared by BlogTag and BlogCategory.

 *

 */

trait BlogObject

{

    /**

     * @return DataList

     */

    public function BlogPosts()

    {

        $blogPosts = parent::BlogPosts();

        $this->extend('updateGetBlogPosts', $blogPosts);

        return $blogPosts;

    }

    /**

     * {@inheritdoc}

     */

    public function getCMSFields()

    {

        $fields = TabSet::create(

            'Root',

            Tab::create(

                'Main',

                TextField::create('Title', _t(__CLASS__ . '.Title', 'Title'))

            )

        );

        $fields = FieldList::create($fields);

        $this->extend('updateCMSFields', $fields);

        return $fields;

    }

    /**

     * {@inheritdoc}

     * @return ValidationResult

     */

    public function validate()

    {

        /** @var ValidationResult $validation */

        $validation = parent::validate();

        if (!$validation->isValid()) {

            return $validation;

        }

        $blog = $this->Blog();

        if (!$blog || !$blog->exists()) {

            return $validation;

        }

        if ($this->getDuplicatesByField('Title')->count() > 0) {

            $validation->addError($this->getDuplicateError(), self::DUPLICATE_EXCEPTION);

        }

        return $validation;

    }

    /**

     * Returns a relative link to this category.

     *

     * @return string

     */

    public function getLink()

    {

        return Controller::join_links(

            $this->Blog()->Link(),

            $this->getListUrlSegment(),

            $this->URLSegment

        );

    }

    /**

     * Inherits from the parent blog or can be overwritten using a DataExtension.

     *

     * @param null|Member $member

     *

     * @return bool

     */

    public function canView($member = null)

    {

        $extended = $this->extendedCan(__FUNCTION__, $member);

        if ($extended !== null) {

            return $extended;

        }

        return $this->Blog()->canView($member);

    }

    /**

     * {@inheritdoc}

     */

    public function canCreate($member = null, $context = [])

    {

        $extended = $this->extendedCan(__FUNCTION__, $member);

        if ($extended !== null) {

            return $extended;

        }

        $permission = Blog::config()->grant_user_permission;

        return Permission::checkMember($member, $permission);

    }

    /**

     * Inherits from the parent blog or can be overwritten using a DataExtension.

     *

     * @param null|Member $member

     *

     * @return bool

     */

    public function canDelete($member = null)

    {

        $extended = $this->extendedCan(__FUNCTION__, $member);

        if ($extended !== null) {

            return $extended;

        }

        return $this->Blog()->canDelete($member);

    }

    /**

     * Inherits from the parent blog or can be overwritten using a DataExtension.

     *

     * @param null|Member $member

     *

     * @return bool

     */

    public function canEdit($member = null)

    {

        $extended = $this->extendedCan(__FUNCTION__, $member);

        if ($extended !== null) {

            return $extended;

        }

        return $this->Blog()->canEdit($member);

    }

    /**

     * {@inheritdoc}

     */

    protected function onBeforeWrite()

    {

        parent::onBeforeWrite();

        if ($this->exists() || empty($this->URLSegment)) {

            return $this->generateURLSegment();

        }

    }

    /**

     * Generates a unique URLSegment from the title.

     *

     * @param int $increment

     *

     * @return string

     */

    public function generateURLSegment($increment = 0)

    {

        $increment = (int) $increment;

        $filter = URLSegmentFilter::create();

        // Setting this to on. Because of the UI flow, it would be quite a lot of work

        // to support turning this off. (ie. the add by title flow would not work).

        // If this becomes a problem we can approach it then.

        // @see https://github.com/silverstripe/silverstripe-blog/issues/376

        $filter->setAllowMultibyte(true);

        $this->URLSegment = $filter->filter($this->Title);

        if ($increment > 0) {

            $this->URLSegment .= '-' . $increment;

        }

        if ($this->getDuplicatesByField('URLSegment')->count() > 0) {

            $this->generateURLSegment($increment + 1);

        }

        return $this->URLSegment;

    }

    /**

     * Looks for objects o the same type and the same value by the given Field

     *

     * @param  string $field E.g. URLSegment or Title

     * @return DataList

     */

    protected function getDuplicatesByField($field)

    {

        $duplicates = DataList::create(self::class)

            ->filter(

                [

                    $field   => $this->$field,

                    'BlogID' => (int) $this->BlogID

                ]

            );

        if ($this->ID) {

            $duplicates = $duplicates->exclude('ID', $this->ID);

        }

        return $duplicates;

    }

    /**

     * This returns the url segment for the listing page.

     * eg. 'categories' in /my-blog/categories/category-url

     *

     * This is not editable at the moment, but a method is being used incase we want

     * to make it editable in the future. We can use this method to provide logic

     * without replacing multiple areas of the code base. We're also not being opinionated

     * about how the segment should be obtained at the moment and allowing for the

     * implementation to decide.

     *

     * @return string

     */

    abstract protected function getListUrlSegment();

    /**

     * Returns an error message for this object when it tries to write a duplicate.

     *

     * @return string

     */

    abstract protected function getDuplicateError();

}