XML中的自定义字段未在数据库中保存参数

Question

This is code which creates custom field:

<?php

defined('_JEXEC') or die('Restricted access');

class JFormFieldCustom extends JFormField {

    protected $type = 'Custom';

    protected function getInput() {

        $db = JFactory::getDbo();

        $query = $db->getQuery(true);
        $query = 'SELECT id, title FROM #__content';
        $db->setQuery($query);
        $rows = $db->loadObjectList();

        $result = '';
        foreach ($rows as $row) {
            $result .= '<label>' . $row->title  . '</label><input type=checkbox name=article  value="' . $row->id .'"/>';
        }
        return $result;
    }

}
?>

And the code into XML file:

<field name="checkboxes" type="custom" default="" label="Articles" description="" />

The problem is that nothing is saved as params into DB. What is wrong here?

Answer 1

Several problems.

HTML & PHP Forms

If we unravel your for loop with some dummy data we get the following:

<label>My Article Title 1</label><input type=checkbox name=article  value="1" />
<label>My Article Title 2</label><input type=checkbox name=article  value="2" />
<label>My Article Title 3</label><input type=checkbox name=article  value="3" />
<label>My Article Title 4</label><input type=checkbox name=article  value="4" />

So the most obvious problem is that you're passing the check boxes back as a single values (all with the same name) where your code indicates that you really want an array.

That HTML will render like this:

and when submitted PHP will perceive it like this:

var_dump($_POST);

array (size=1)
  'article' => string '3' (length=1)

So, to get an array of a form element in PHP you will need to append [] to the end of the name, ie article[] , to make the display vertical I've also added a <br> after each checkbox and properly quoted the attributes of the <input> . That gets us this:

<label>My Article Title 1</label><input type="checkbox" name="articles[]"  value="1" /><br>
<label>My Article Title 2</label><input type="checkbox" name="articles[]"  value="2" /><br>
<label>My Article Title 3</label><input type="checkbox" name="articles[]"  value="3" /><br>
<label>My Article Title 4</label><input type="checkbox" name="articles[]"  value="4" /><br>

When this is submitted we can see PHP see's all the check options:

var_dump($_POST);

array (size=1)
  'articles' => 
    array (size=2)
      0 => string '1' (length=1)
      1 => string '3' (length=1)

Joomla Problems

1. You create a JDatabaseQuery object with the line $query = $db->getQuery(true); , but then immediately destroy it by overwriting in with a string of SQL.
2. Your table and column names are not appropriately quoted, quoting helps to prevent injection risks and reserved word conflicts. As quoting can vary by the underlying database, JDatabase provides a series of useful functions to make your SQL portable across the various DB's it supports so your query can be rewritten as:

$query = $db->getQuery(true);
$query->select(array($db->quoteName('id'), $db->quoteName('title')));
$db->setQuery($query);
$rows = $db->loadObjectList();

3. I would recommend not using a generic type of 'Custom' (I realise that lots of tutorial use it but they are just examples), to avoid conflicts try something more descriptive like ArticleCheckboxes . So your PHP ends up more like this:

class JFormFieldArticlesCheckboxes extends JFormField
{

    protected $type = 'ArticlesCheckboxes';

    protected function getInput()
    {

        $db = JFactory::getDbo();

        $query = $db->getQuery(true);
        $query->select(array($db->quoteName('id'), $db->quoteName('title')));
        $db->setQuery($query);
        $rows = $db->loadObjectList();

        $result = '';

        foreach ($rows as $row)
        {
            $result .= '<label>' . $row->title . '</label><input type="checkbox" name="articles[]"  value="' . $row->id . '"/>';
        }

        return $result;
    }
}

4. I presume this is preliminary SQL as right now this will pull back every article in the website, published or not, expired and trashed even. You may want to consider using the com_content model for articles ContentModelArticles which will give you all the advantages of using a JModelList object, like filtering, and getItems() which returns a list of articles you can use.