I am working on a student management system.
How can I add extra select field (e.g. select user, select class.) to com_content, so that I can assign the article to the specific student (e.g. mark-sheet) and the parent can also see his child student data (mark-sheet)?
I have created user groups and access levels for all classes. For example a student log-in and can see his result but cannot see any other student's result, and same works for parent.
This article shows you how to do that http://magazine.joomla.org/issues/issue-dec-2014/item/2402-adding-fields-to-com-content-the-smart-way & https://github.com/katalystsol/plg_content_ksextras
Basically it involves create a custom cotent plugin that hooks into Joomla's onContentPrepareForm() and onContentPrepareData() methods.
here's a copy of the plugin's code
<?php
/**
* @copyright Copyright 2014 Katalyst Solutions, LLC. All Rights Reserved.
* @license GNU General Public License version 2 or later;
*/
defined('_JEXEC') or die;
jimport('joomla.plugin.plugin');
/**
* This is a custom testimonial plugin class to add additional fields to com_content to allow it to be used for reviews/testimonials
* and output the data using schema.org/Review. It will add an additional tab called Testimonial
*/
class plgContentKSExtras extends JPlugin
{
/** var string Name of the plugin */
protected $plg_name;
/** var array List of fields to look for in the $attribs */
protected $ksfields;
/** var string The organization name */
protected $organization;
/** var string Organization Type used for Schema.org */
protected $organization_type;
/** var string Category */
protected $category;
/** var boolean Limit plugin to selected category */
protected $limit_to_category;
/** var boolean Include child categories */
protected $include_child_categories;
public function __construct(& $subject, $config)
{
// We only want to use this with com_content
$jinput = JFactory::getApplication()->input;
$option = $jinput->get('option');
if ($option <> 'com_content')
{
return true;
}
parent::__construct($subject, $config);
$this->plg_name = 'ksextras';
$this->ksfields = $this->setKSFields();
// Get the plugin parameters
$this->organization = $this->params->get('organization');
$this->organization_type = $this->params->get('organization_type');
$this->category = $this->params->get('category');
$this->limit_to_category = $this->params->get('limit_to_category');
$this->include_child_categories = $this->params->get('include_child_categories');
// Load the language file for the plugin
$this->loadLanguage();
}
/**
* Set the values for the ksfields array
* These should correspond to the fields in extras/testimonial.xml
* These should not use the same name as any com_content attribs fields
*
* @return array
*/
protected function setKSFields()
{
$ksfields = array (
'testimonial_by',
'author_job_title',
'author_affiliation',
'rating',
'author_address',
'author_locality',
'author_region',
'author_postal_code',
'author_url',
);
return $ksfields;
}
/**
* Prepare the form to add to the article edit
*
* @param object $form
* @param object $data
*
* @return bool
*/
public function onContentPrepareForm($form, $data)
{
// If the category id is set, then check if the plugin should be limited to a specific category
if (!empty($data->catid))
{
$this->getChildCategories($data->catid);
if ($this->limit_to_category && !$this->checkCategory($data->catid))
{
return true;
}
}
if (!($form instanceof JForm))
{
$this->_subject->setError('JERROR_NOT_A_FORM');
return false;
}
// Check that we are manipulating a valid form
$name = $form->getName();
if (!in_array($name, array('com_content.article')))
{
return true;
}
// Add the extra fields to the form
JForm::addFormPath(dirname(__FILE__) . '/extras');
$form->loadFile('testimonial', false);
// Load the data from table into the form
$articleId = isset($data->id) ? $data->id : 0;
// If there is already an $articleId, then the article is in edit mode
// and we need to retrieve the data from the database
if ($articleId)
{
// Load the data from the database
$db = JFactory::getDbo();
$query = $db->getQuery(true);
$query->select('article_id, data');
$query->from('#__content_ksextras');
$query->where('article_id = '.$db->Quote($articleId));
$db->setQuery($query);
$attribs = $db->loadObject();
// Check for a database error.
if ($db->getErrorNum())
{
$this->_subject->setError($db->getErrorMsg());
return false;
}
// json_decode the data
if (!empty($attribs->data))
{
$ksdata = json_decode(json_decode($attribs->data));
}
}
// fill in the form with data
if(isset($attribs))
{
foreach ($this->ksfields as $ksfield)
{
$data->attribs[$ksfield] = isset($ksdata->$ksfield) ? $ksdata->$ksfield : '';
}
}
return true;
}
/**
* Runs on content preparation.
* Called after the data for a JForm has been retrieved.
*
* @param string $context The context for the data
* @param object $data An object containing the data for the form.
*
* @return boolean
*/
public function onContentPrepareData($context, $data)
{
if (is_object($data))
{
$articleId = isset($data->id) ? $data->id : 0;
if ($articleId > 0)
{
// Load the data from the database
$db = JFactory::getDbo();
$query = $db->getQuery(true);
$query->select('data');
$query->from('#__content_ksextras');
$query->where('article_id = '.$db->Quote($articleId));
$db->setQuery($query);
$results = $db->loadObject();
// Check for a database error
if ($db->getErrorNum())
{
$this->_subject->setError($db->getErrorMsg());
return false;
}
$ksdata = (count($results)) ? json_decode(json_decode($results->data)) : new stdClass;
// Merge the data
$data->attribs = array();
foreach ($this->ksfields as $ksfield)
{
$data->attribs[$ksfield] = isset($ksdata->$ksfield) ? $ksdata->$ksfield : '';
}
}
else
{
// Load the form
JForm::addFormPath(dirname(__FILE__).'/extras');
$form = new JForm('com_content.article');
$form->loadFile('testimonial', false);
// Merge the default values
$data->attribs = array();
foreach ($form->getFieldset('attribs') as $field)
{
$data->attribs[] = array($field->fieldname, $field->value);
}
}
}
return true;
}
/**
* Fires after content save post event hook to save custom data into #__content_ksextras
*
* @param $context
* @param $data
* @param $isNew
*
* @return bool
*/
public function onContentAfterSave($context, $data, $isNew)
{
// Check if we are manipulating a valid form
if (!in_array($context, array('com_content.article')))
{
return true;
}
// Get the article id or set to 0 if new article (it should have an id at this point)
$articleId = isset($data->id) ? $data->id : 0;
// Get the attributes
$attribs = json_decode($data->attribs);
// Pull out the extra fields to insert into the table
$ksattribs = array();
foreach ($this->ksfields as $ksfield)
{
$ksattribs[$ksfield] = isset($attribs->$ksfield) ? $attribs->$ksfield : '';
}
$ksattribs = json_encode($ksattribs);
// Get the database object
$db = JFactory::getDbo();
// Check for an existing entry
$db->setQuery('SELECT COUNT(*) FROM #__content_ksextras WHERE article_id = '.$articleId);
$res = $db->loadResult();
// Updating or adding
if (!empty($res)) // updating record
{
$this->updateRecord($ksattribs, $articleId);
}
else // Adding a new record
{
$this->insertRecord($ksattribs, $articleId);
}
}
/**
* Remove the data when the article is deleted
*
* Method is called before (after?) article data is deleted from the database
*
* @param string The context for the content passed to the plugin.
* @param object The data relating to the content that was deleted.
*
* @return bool
* @throws JException
*/
public function onContentAfterDelete($context, $data)
{
// get the article id
$articleId = isset($data->id) ? (int) $data->id : 0;
if ($articleId)
{
try
{
$db = JFactory::getDbo();
$db->setQuery('DELETE FROM #__content_ksextras WHERE article_id = '.$articleId );
if (!$db->execute()) {
throw new Exception($db->getErrorMsg());
}
}
catch (JException $e)
{
$this->_subject->setError($e->getMessage());
return false;
}
}
return true;
}
/**
* The first stage in preparing the content for output
*
* @param $context
* @param $article
* @param $params
* @param $page
*
* @return string
*/
public function onContentPrepare($context, &$article, &$params, $page = 0)
{
if (!isset($article->testimonial) || !count($article->testimonial))
{
return;
}
// add extra css for table
$doc = JFactory::getDocument();
//$doc->addStyleSheet(JURI::base(true).'/plugins/content/ksextras/extras/ksextras.css');
// construct a result table on the fly
jimport('joomla.html.grid');
$table = new JGrid();
// Create columns
$table->addColumn('attr')->addColumn('value');
// populate
$rownr = 0;
foreach ($article->testimonial as $attr => $value)
{
$table->addRow(array('class' => 'row'.($rownr % 2)));
$table->setRowCell('attr', $attr);
$table->setRowCell('value', $value);
$rownr++;
}
// wrap table in a classed <div>
$suffix = $this->params->get('testimonialclass_sfx', 'testimonial');
$html = '<div class="'.$suffix.'">'.(string)$table.'</div>';
$article->text = $html.$article->text;
}
/**
* Insert a new record into the database
*
* @param $attribs our extra fields in object form
* @param $articleId the article id we are relating the fields to
*
* @return bool
* @throws Exception
*/
public function insertRecord($attribs, $articleId)
{
// Get a db connection.
$db = JFactory::getDbo();
// Create a new query object.
$query = $db->getQuery(true);
// Insert columns.
$columns = array('article_id', 'data', 'created', 'created_by');
$user = JFactory::getUser();
$created_by = $user->id;
$created = JFactory::getDate()->toSql();
// Insert values.
$values = array(
$articleId,
$db->quote(json_encode($attribs)),
$db->quote($created),
$created_by,
);
// insert query
$query
->insert($db->quoteName('#__content_ksextras'))
->columns($db->quoteName($columns))
->values(implode(',', $values));
// set the query
$db->setQuery($query);
// execute, throw an exception if we have a problem
if (!$db->execute()) {
throw new Exception($db->getErrorMsg());
}
return true;
}
/**
* Update record function
*
* @param $attribs requires object of attributes from form
* @param $articleId id of the article we are relating to
*
* @return bool
* @throws Exception
*/
protected function updateRecord($attribs, $articleId)
{
$db = JFactory::getDbo();
// Create a new query object.
$query = $db->getQuery(true);
$conditions = array(
'article_id='.$articleId,
);
$user = JFactory::getUser();
$modified_by = $user->id;
$modified = JFactory::getDate()->toSql();
// Fields to update.
$fields = array(
'data='.$db->quote(json_encode($attribs)),
'modified='.$db->quote($modified),
'modified_by='.$modified_by,
);
// update query
$query->update($db->quoteName('#__content_ksextras'))->set($fields)->where($conditions);
// set the query
$db->setQuery($query);
// execute, throw an exception if we have a problem
if (!$db->execute()) {
throw new Exception($db->getErrorMsg());
}
return true;
}
/**
* Check the article category against the category selected by the plugin
*
* @param integer $article_cat The category of the article
*
* @return boolean
*/
protected function checkCategory($article_cat)
{
if ($this->category == $article_cat)
{
return true;
}
// Need to check if the current category's parent or grand-parent
// is the category selected for this plugin
if ($this->include_child_categories)
{
$parents = $this->getParentCategories($article_cat);
if (in_array($this->category, $parents))
{
return true;
}
}
return false;
}
/**
* Get a list of the category children
*
* @param integer $catId The id of the category to check
*
* @return array
*/
protected function getChildCategories($catId)
{
jimport('joomla.application.categories');
$categories = JCategories::getInstance('Content');
$cat = $categories->get($catId);
$children = $cat->getChildren();
$childCats = array();
foreach ($children as $child)
{
$childCats[] = $child->id;
}
return $childCats;
}
/**
* Get a list of the category parent(s)
*
* @param integer $catId The id of the category to check
*
* @return array
*/
protected function getParentCategories($catId)
{
$parentCats = array();
jimport('joomla.application.categories');
$categories = JCategories::getInstance('Content');
$cat = $categories->get($catId);
// Check the parent_id. If it is an integer > 0, update the array and
// check for a parent_id of the parent... Only going up 2 levels...
if ((int)$cat->parent_id)
{
$parentCats[] = $cat->parent_id;
$parent = $cat->getParent();
if ((int) $parent->parent_id)
{
$parentCats[] = $parent->parent_id;
}
}
return $parentCats;
}
}
````
