Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * This file contains the parent class for moodle blocks, block_base.

 *

 * @package    core_block

 * @license    http://www.gnu.org/copyleft/gpl.html GNU Public License

 */

/// Constants

/**

 * Block type of list. Contents of block should be set as an associative array in the content object as items ($this->content->items). Optionally include footer text in $this->content->footer.

 */

define('BLOCK_TYPE_LIST',    1);

/**

 * Block type of text. Contents of block should be set to standard html text in the content object as items ($this->content->text). Optionally include footer text in $this->content->footer.

 */

define('BLOCK_TYPE_TEXT',    2);

/**

 * Block type of tree. $this->content->items is a list of tree_item objects and $this->content->footer is a string.

 */

define('BLOCK_TYPE_TREE',    3);

/**

 * Class for describing a moodle block, all Moodle blocks derive from this class

 *

 * @author Jon Papaioannou

 * @package core_block

 */

class block_base {

    /**

     * Internal var for storing/caching translated strings

     * @var string $str

     */

    var $str;

    /**

     * The title of the block to be displayed in the block title area.

     * @var string $title

     */

    var $title         = NULL;

    /**

     * The name of the block to be displayed in the block title area if the title is empty.

     * @var string arialabel

     */

    var $arialabel         = NULL;

    /**

     * The type of content that this block creates. Currently support options - BLOCK_TYPE_LIST, BLOCK_TYPE_TEXT

     * @var int $content_type

     */

    var $content_type  = BLOCK_TYPE_TEXT;

    /**

     * An object to contain the information to be displayed in the block.

     * @var stdClass|null $content

     */

    var $content       = NULL;

    /**

     * The initialized instance of this block object.

     * @var stdClass $instance

     */

    var $instance      = NULL;

    /**

     * The page that this block is appearing on.

     * @var moodle_page

     */

    public $page       = NULL;

    /**

     * This block's context.

     * @var context

     */

    public $context    = NULL;

    /**

     * An object containing the instance configuration information for the current instance of this block.

     * @var stdClass $config

     */

    var $config        = NULL;

    /**

     * How often the cronjob should run, 0 if not at all.

     * @var int $cron

     */

    var $cron          = NULL;

/// Class Functions

    /**

     * Fake constructor to keep PHP5 happy

     *

     */

    function __construct() {

        $this->init();

    }

    /**

     * Function that can be overridden to do extra cleanup before

     * the database tables are deleted. (Called once per block, not per instance!)

     */

    function before_delete() {

    }

    /**

     * Returns the block name, as present in the class name,

     * the database, the block directory, etc etc.

     *

     * @return string

     */

    function name() {

        // Returns the block name, as present in the class name,

        // the database, the block directory, etc etc.

        $myname = strtolower(get_class($this));

        return substr($myname, strpos($myname, '_') + 1);

    }

    /**

     * Parent class version of this function simply returns NULL

     * This should be implemented by the derived class to return

     * the content object.

     *

     * @return stdClass

     */

    function get_content() {

        // This should be implemented by the derived class.

        return NULL;

    }

    /**

     * Returns the class $title var value.

     *

     * Intentionally doesn't check if a title is set.

     * This is already done in {@link _self_test()}

     *

     * @return string $this->title

     */

    function get_title() {

        // Intentionally doesn't check if a title is set. This is already done in _self_test()

        return $this->title;

    }

    /**

     * Returns the class $content_type var value.

     *

     * Intentionally doesn't check if content_type is set.

     * This is already done in {@link _self_test()}

     *

     * @return int $this->content_type

     */

    function get_content_type() {

        // Intentionally doesn't check if a content_type is set. This is already done in _self_test()

        return $this->content_type;

    }

    /**

     * Returns true or false, depending on whether this block has any content to display

     * and whether the user has permission to view the block

     *

     * @return bool

     */

    function is_empty() {

        if ( !has_capability('moodle/block:view', $this->context) ) {

            return true;

        }

        $this->get_content();

        return(empty($this->content->text) && empty($this->content->footer));

    }

    /**

     * First sets the current value of $this->content to NULL

     * then calls the block's {@link get_content()} function

     * to set its value back.

     *

     * @return stdClass

     */

    function refresh_content() {

        // Nothing special here, depends on content()

        $this->content = NULL;

        return $this->get_content();

    }

    /**

     * Return a block_contents object representing the full contents of this block.

     *

     * This internally calls ->get_content(), and then adds the editing controls etc.

     *

     * You probably should not override this method, but instead override

     * {@link html_attributes()}, {@link formatted_contents()} or {@link get_content()},

     * {@link hide_header()}, {@link (get_edit_controls)}, etc.

     *

     * @return block_contents|null a representation of the block, for rendering.

     * @since Moodle 2.0.

     */

    public function get_content_for_output($output) {

        global $CFG;

        // We can exit early if the current user doesn't have the capability to view the block.

        if (!has_capability('moodle/block:view', $this->context)) {

            return null;

        }

        $bc = new block_contents($this->html_attributes());

        $bc->attributes['data-block'] = $this->name();

        $bc->blockinstanceid = $this->instance->id;

        $bc->blockpositionid = $this->instance->blockpositionid;

        if ($this->instance->visible) {

            $bc->content = $this->formatted_contents($output);

            if (!empty($this->content->footer)) {

                $bc->footer = $this->content->footer;

            }

        } else {

            $bc->add_class('invisibleblock');

        }

        if (!$this->hide_header()) {

            $bc->title = $this->title;

        }

        if (empty($bc->title)) {

            $bc->arialabel = new lang_string('pluginname', get_class($this));

            $this->arialabel = $bc->arialabel;

        }

        if ($this->page->user_is_editing() && $this->instance_can_be_edited()) {

            $bc->controls = $this->page->blocks->edit_controls($this);

        } else {

            // we must not use is_empty on hidden blocks

            if ($this->is_empty() && !$bc->controls) {

                return null;

            }

        }

        if (empty($CFG->allowuserblockhiding)

                || (empty($bc->content) && empty($bc->footer))

                || !$this->instance_can_be_collapsed()) {

            $bc->collapsible = block_contents::NOT_HIDEABLE;

        } else if (get_user_preferences('block' . $bc->blockinstanceid . 'hidden', false)) {

            $bc->collapsible = block_contents::HIDDEN;

        } else {

            $bc->collapsible = block_contents::VISIBLE;

        }

        if ($this->instance_can_be_docked() && !$this->hide_header()) {

            $bc->dockable = true;

        }

        $bc->annotation = ''; // TODO MDL-19398 need to work out what to say here.

        return $bc;

    }

    /**

     * Return an object containing all the block content to be returned by external functions.

     *

     * If your block is returning formatted content or provide files for download, you should override this method to use the

     * \core_external\util::format_text, \core_external\util::format_string functions for formatting or external_util::get_area_files for files.

     *

     * @param  core_renderer $output the rendered used for output

     * @return stdClass      object containing the block title, central content, footer and linked files (if any).

     * @since  Moodle 3.6

     */

    public function get_content_for_external($output) {

        $bc = new stdClass;

        $bc->title = null;

        $bc->content = null;

        $bc->contentformat = FORMAT_HTML;

        $bc->footer = null;

        $bc->files = [];

        if ($this->instance->visible) {

            $bc->content = $this->formatted_contents($output);

            if (!empty($this->content->footer)) {

                $bc->footer = $this->content->footer;

            }

        }

        if (!$this->hide_header()) {

            $bc->title = $this->title;

        }

        return $bc;

    }

    /**

     * Return the plugin config settings for external functions.

     *

     * In some cases the configs will need formatting or be returned only if the current user has some capabilities enabled.

     *

     * @return stdClass the configs for both the block instance and plugin (as object with name -> value)

     * @since Moodle 3.8

     */

    public function get_config_for_external() {

        return (object) [

            'instance' => new stdClass(),

            'plugin' => new stdClass(),

        ];

    }

    /**

     * Convert the contents of the block to HTML.

     *

     * This is used by block base classes like block_list to convert the structured

     * $this->content->list and $this->content->icons arrays to HTML. So, in most

     * blocks, you probaby want to override the {@link get_contents()} method,

     * which generates that structured representation of the contents.

     *

     * @param $output The core_renderer to use when generating the output.

     * @return string the HTML that should appearn in the body of the block.

     * @since Moodle 2.0.

     */

    protected function formatted_contents($output) {

        $this->get_content();

        $this->get_required_javascript();

        if (!empty($this->content->text)) {

            return $this->content->text;

        } else {

            return '';

        }

    }

    /**

     * Tests if this block has been implemented correctly.

     * Also, $errors isn't used right now

     *

     * @return boolean

     */

    function _self_test() {

        // Tests if this block has been implemented correctly.

        // Also, $errors isn't used right now

        $errors = array();

        $correct = true;

        if ($this->get_title() === NULL) {

            $errors[] = 'title_not_set';

            $correct = false;

        }

        if (!in_array($this->get_content_type(), array(BLOCK_TYPE_LIST, BLOCK_TYPE_TEXT, BLOCK_TYPE_TREE))) {

            $errors[] = 'invalid_content_type';

            $correct = false;

        }

        //following selftest was not working when roles&capabilities were used from block

/*        if ($this->get_content() === NULL) {

            $errors[] = 'content_not_set';

            $correct = false;

        }*/

        $formats = $this->applicable_formats();

        if (empty($formats) || array_sum($formats) === 0) {

            $errors[] = 'no_formats';

            $correct = false;

        }

        return $correct;

    }

    /**

     * Subclasses should override this and return true if the

     * subclass block has a settings.php file.

     *

     * @return boolean

     */

    function has_config() {

        return false;

    }

    /**

     * Default behavior: save all variables as $CFG properties

     * You don't need to override this if you 're satisfied with the above

     *

     * @deprecated since Moodle 2.9 MDL-49385 - Please use Admin Settings functionality to save block configuration.

     */

    function config_save($data) {

        throw new coding_exception('config_save() can not be used any more, use Admin Settings functionality to save block configuration.');

    }

    /**

     * Which page types this block may appear on.

     *

     * The information returned here is processed by the

     * {@link blocks_name_allowed_in_format()} function. Look there if you need

     * to know exactly how this works.

     *

     * Default case: everything except mod and tag.

     *

     * @return array page-type prefix => true/false.

     */

    function applicable_formats() {

        // Default case: the block can be used in courses and site index, but not in activities

        return array('all' => true, 'mod' => false, 'tag' => false);

    }

    /**

     * Default return is false - header will be shown

     * @return boolean

     */

    function hide_header() {

        return false;

    }

    /**

     * Return any HTML attributes that you want added to the outer <div> that

     * of the block when it is output.

     *

     * Because of the way certain JS events are wired it is a good idea to ensure

     * that the default values here still get set.

     * I found the easiest way to do this and still set anything you want is to

     * override it within your block in the following way

     *

     * <code php>

     * function html_attributes() {

     *    $attributes = parent::html_attributes();

     *    $attributes['class'] .= ' mynewclass';

     *    return $attributes;

     * }

     * </code>

     *

     * @return array attribute name => value.

     */

    function html_attributes() {

        $attributes = array(

            'id' => 'inst' . $this->instance->id,

            'class' => 'block_' . $this->name() . ' block',

            'role' => $this->get_aria_role()

        );

        if ($this->hide_header()) {

            $attributes['class'] .= ' no-header';

        }

        if ($this->instance_can_be_docked() && get_user_preferences('docked_block_instance_' . $this->instance->id, 0)) {

            $attributes['class'] .= ' dock_on_load';

        }

        return $attributes;

    }

    /**

     * Set up a particular instance of this class given data from the block_insances

     * table and the current page. (See {@link block_manager::load_blocks()}.)

     *

     * @param stdClass $instance data from block_insances, block_positions, etc.

     * @param moodle_page $page the page this block is on.

     */

    function _load_instance($instance, $page) {

        if (!empty($instance->configdata)) {

            $this->config = unserialize_object(base64_decode($instance->configdata));

        }

        $this->instance = $instance;

        $this->context = context_block::instance($instance->id);

        $this->page = $page;

        $this->specialization();

    }

    /**

     * Allows the block to load any JS it requires into the page.

     *

     * By default this function simply permits the user to dock the block if it is dockable.

     *

     * Left null as of MDL-64506.

     */

    function get_required_javascript() {

    }

    /**

     * This function is called on your subclass right after an instance is loaded

     * Use this function to act on instance data just after it's loaded and before anything else is done

     * For instance: if your block will have different title's depending on location (site, course, blog, etc)

     */

    function specialization() {

        // Just to make sure that this method exists.

    }

    /**

     * Is each block of this type going to have instance-specific configuration?

     * Normally, this setting is controlled by {@link instance_allow_multiple()}: if multiple

     * instances are allowed, then each will surely need its own configuration. However, in some

     * cases it may be necessary to provide instance configuration to blocks that do not want to

     * allow multiple instances. In that case, make this function return true.

     * I stress again that this makes a difference ONLY if {@link instance_allow_multiple()} returns false.

     * @return boolean

     */

    function instance_allow_config() {

        return false;

    }

    /**

     * Are you going to allow multiple instances of each block?

     * If yes, then it is assumed that the block WILL USE per-instance configuration

     * @return boolean

     */

    function instance_allow_multiple() {

        // Are you going to allow multiple instances of each block?

        // If yes, then it is assumed that the block WILL USE per-instance configuration

        return false;

    }

    /**

     * Serialize and store config data

     */

    function instance_config_save($data, $nolongerused = false) {

        global $DB;

        $DB->update_record('block_instances', ['id' => $this->instance->id,

                'configdata' => base64_encode(serialize($data)), 'timemodified' => time()]);

    }

    /**

     * Replace the instance's configuration data with those currently in $this->config;

     */

    function instance_config_commit($nolongerused = false) {

        global $DB;

        $this->instance_config_save($this->config);

    }

    /**

     * Do any additional initialization you may need at the time a new block instance is created

     * @return boolean

     */

    function instance_create() {

        return true;

    }

    /**

     * Copy any block-specific data when copying to a new block instance.

     * @param int $fromid the id number of the block instance to copy from

     * @return boolean

     */

    public function instance_copy($fromid) {

        return true;

    }

    /**

     * Delete everything related to this instance if you have been using persistent storage other than the configdata field.

     * @return boolean

     */

    function instance_delete() {

        return true;

    }

    /**

     * Allows the block class to have a say in the user's ability to edit (i.e., configure) blocks of this type.

     * The framework has first say in whether this will be allowed (e.g., no editing allowed unless in edit mode)

     * but if the framework does allow it, the block can still decide to refuse.

     * @return boolean

     */

    function user_can_edit() {

        global $USER;

        if (has_capability('moodle/block:edit', $this->context)) {

            return true;

        }

        // The blocks in My Moodle are a special case.  We want them to inherit from the user context.

        if (!empty($USER->id)

            && $this->instance->parentcontextid == $this->page->context->id   // Block belongs to this page

            && $this->page->context->contextlevel == CONTEXT_USER             // Page belongs to a user

            && $this->page->context->instanceid == $USER->id) {               // Page belongs to this user

            return has_capability('moodle/my:manageblocks', $this->page->context);

        }

        return false;

    }

    /**

     * Allows the block class to have a say in the user's ability to create new instances of this block.

     * The framework has first say in whether this will be allowed (e.g., no adding allowed unless in edit mode)

     * but if the framework does allow it, the block can still decide to refuse.

     * This function has access to the complete page object, the creation related to which is being determined.

     *

     * @param moodle_page $page

     * @return boolean

     */

    function user_can_addto($page) {

        global $CFG;

        require_once($CFG->dirroot . '/user/lib.php');

        // List of formats this block supports.

        $formats = $this->applicable_formats();

        // Check if user is trying to add blocks to their profile page.

        $userpagetypes = user_page_type_list($page->pagetype, null, null);

        if (array_key_exists($page->pagetype, $userpagetypes)) {

            $capability = 'block/' . $this->name() . ':addinstance';

            return $this->has_add_block_capability($page, $capability)

                && has_capability('moodle/user:manageownblocks', $page->context);

        }

        // The blocks in My Moodle are a special case and use a different capability.

        $mypagetypes = my_page_type_list($page->pagetype); // Get list of possible my page types.

        if (array_key_exists($page->pagetype, $mypagetypes)) { // Ensure we are on a page with a my page type.

            // If the block cannot be displayed on /my it is ok if the myaddinstance capability is not defined.

            // Is 'my' explicitly forbidden?

            // If 'all' has not been allowed, has 'my' been explicitly allowed?

            if ((isset($formats['my']) && $formats['my'] == false)

                || (empty($formats['all']) && empty($formats['my']))) {

                // Block cannot be added to /my regardless of capabilities.

                return false;

            } else {

                $capability = 'block/' . $this->name() . ':myaddinstance';

                return $this->has_add_block_capability($page, $capability)

                       && has_capability('moodle/my:manageblocks', $page->context);

            }

        }

        // Check if this is a block only used on /my.

        unset($formats['my']);

        if (empty($formats)) {

            // Block can only be added to /my - return false.

            return false;

        }

        $capability = 'block/' . $this->name() . ':addinstance';

        if ($this->has_add_block_capability($page, $capability)

                && has_capability('moodle/block:edit', $page->context)) {

            return true;

        }

        return false;

    }

    /**

     * Returns true if the user can add a block to a page.

     *

     * @param moodle_page $page

     * @param string $capability the capability to check

     * @return boolean true if user can add a block, false otherwise.

     */

    private function has_add_block_capability($page, $capability) {

        // Check if the capability exists.

        if (!get_capability_info($capability)) {

            // Debug warning that the capability does not exist, but no more than once per page.

            static $warned = array();

            if (!isset($warned[$this->name()])) {

                debugging('The block ' .$this->name() . ' does not define the standard capability ' .

                        $capability , DEBUG_DEVELOPER);

                $warned[$this->name()] = 1;

            }

            // If the capability does not exist, the block can always be added.

            return true;

        } else {

            return has_capability($capability, $page->context);

        }

    }

    static function get_extra_capabilities() {

        return array('moodle/block:view', 'moodle/block:edit');

    }

    /**

     * Can be overridden by the block to prevent the block from being dockable.

     *

     * @return bool

     *

     * Return false as per MDL-64506

     */

    public function instance_can_be_docked() {

        return false;

    }

    /**

     * If overridden and set to false by the block it will not be hidable when

     * editing is turned on.

     *

     * @return bool

     */

    public function instance_can_be_hidden() {

        return true;

    }

    /**

     * If overridden and set to false by the block it will not be collapsible.

     *

     * @return bool

     */

    public function instance_can_be_collapsed() {

        return true;

    }

    /**

     * If overridden and set to false by the block it will not be editable.

     *

     * @return bool

     */

    public function instance_can_be_edited() {

        return true;

    }

    /** @callback callback functions for comments api */

    public static function comment_template($options) {

        $ret = <<<EOD

<div class="comment-userpicture">___picture___</div>

<div class="comment-content">

    ___name___ - <span>___time___</span>

    <div>___content___</div>

</div>

EOD;

        return $ret;

    }

    public static function comment_permissions($options) {

        return array('view'=>true, 'post'=>true);

    }

    public static function comment_url($options) {

        return null;

    }

    public static function comment_display($comments, $options) {

        return $comments;

    }

    public static function comment_add(&$comments, $options) {

        return true;

    }

    /**

     * Returns the aria role attribute that best describes this block.

     *

     * Region is the default, but this should be overridden by a block is there is a region child, or even better

     * a landmark child.

     *

     * Options are as follows:

     *    - landmark

     *      - application

     *      - banner

     *      - complementary

     *      - contentinfo

     *      - form

     *      - main

     *      - navigation

     *      - search

     *

     * @return string

     */

    public function get_aria_role() {

        return 'complementary';

    }

    /**

     * This method can be overriden to add some extra checks to decide whether the block can be added or not to a page.

     * It doesn't need to do the standard capability checks as they will be performed by has_add_block_capability().

     * This method is user agnostic. If you want to check if a user can add a block or not, you should use user_can_addto().

     *

     * @param moodle_page $page The page where this block will be added.

     * @return bool Whether the block can be added or not to the given page.

     */

    public function can_block_be_added(moodle_page $page): bool {

        return true;

    }

}

/**

 * Specialized class for displaying a block with a list of icons/text labels

 *

 * The get_content method should set $this->content->items and (optionally)

 * $this->content->icons, instead of $this->content->text.

 *

 * @author Jon Papaioannou

 * @package core_block

 */

class block_list extends block_base {

    var $content_type  = BLOCK_TYPE_LIST;

    function is_empty() {

        if ( !has_capability('moodle/block:view', $this->context) ) {

            return true;

        }

        $this->get_content();

        return (empty($this->content->items) && empty($this->content->footer));

    }

    protected function formatted_contents($output) {

        $this->get_content();

        $this->get_required_javascript();

        if (!empty($this->content->items)) {

            return $output->list_block_contents($this->content->icons, $this->content->items);

        } else {

            return '';

        }

    }

    function html_attributes() {

        $attributes = parent::html_attributes();

        $attributes['class'] .= ' list_block';

        return $attributes;

    }

}

/**

 * Specialized class for displaying a tree menu.

 *

 * The {@link get_content()} method involves setting the content of

 * <code>$this->content->items</code> with an array of {@link tree_item}

 * objects (these are the top-level nodes). The {@link tree_item::children}

 * property may contain more tree_item objects, and so on. The tree_item class

 * itself is abstract and not intended for use, use one of it's subclasses.

 *

 * Unlike {@link block_list}, the icons are specified as part of the items,

 * not in a separate array.

 *

 * @author Alan Trick

 * @package core_block

 * @internal this extends block_list so we get is_empty() for free

 */

class block_tree extends block_list {

    /**

     * @var int specifies the manner in which contents should be added to this

     * block type. In this case <code>$this->content->items</code> is used with

     * {@link tree_item}s.

     */

    public $content_type = BLOCK_TYPE_TREE;

    /**

     * Make the formatted HTML ouput.

     *

     * Also adds the required javascript call to the page output.

     *

     * @param core_renderer $output

     * @return string HTML

     */

    protected function formatted_contents($output) {

        // based of code in admin_tree

        global $PAGE; // TODO change this when there is a proper way for blocks to get stuff into head.

        static $eventattached;

        if ($eventattached===null) {

            $eventattached = true;

        }

        if (!$this->content) {

            $this->content = new stdClass;

            $this->content->items = array();

        }

        $this->get_required_javascript();

        $this->get_content();

        $content = $output->tree_block_contents($this->content->items,array('class'=>'block_tree list'));

        return $content;

    }

}