new formslib element type advcheckbox prepends a hidden element to a checkbox so...

diff --git a/lib/form/advcheckbox.php b/lib/form/advcheckbox.php
new file mode 100644 (file)
index 0000000..65bee64
--- /dev/null
+++ b/lib/form/advcheckbox.php
@@ -0,0 +1,224 @@
+<?php
+// $Id$
+
+require_once "$CFG->libdir/form/HTML/QuickForm/checkbox.php";
+
+/**
+ * HTML class for an advanced checkbox type field
+ *
+ * Basically this fixes a problem that HTML has had
+ * where checkboxes can only pass a single value (the
+ * value of the checkbox when checked).  A value for when
+ * the checkbox is not checked cannot be passed, and
+ * furthermore the checkbox variable doesn't even exist if
+ * the checkbox was submitted unchecked.
+ *
+ * It works by prepending a hidden field with the same name and
+ * another "unchecked" value to the checkbox. If the checkbox is
+ * checked, PHP overwrites the value of the hidden field with
+ * its value.
+ *
+ * @author       Jason Rust <jrust@php.net>
+ * @since        2.0
+ * @access       public
+ */
+class MoodleQuickForm_advcheckbox extends MoodleQuickForm_checkbox
+{
+    // {{{ properties
+
+    /**
+     * The values passed by the hidden elment
+     *
+     * @var array
+     * @access private
+     */
+    var $_values = null;
+
+    /**
+     * The default value
+     *
+     * @var boolean
+     * @access private
+     */
+    var $_currentValue = null;
+
+    // }}}
+    // {{{ constructor
+
+    /**
+     * Class constructor
+     *
+     * @param     string    $elementName    (optional)Input field name attribute
+     * @param     string    $elementLabel   (optional)Input field label
+     * @param     string    $text           (optional)Text to put after the checkbox
+     * @param     mixed     $attributes     (optional)Either a typical HTML attribute string
+     *                                      or an associative array
+     * @param     mixed     $values         (optional)Values to pass if checked or not checked
+     *
+     * @since     1.0
+     * @access    public
+     * @return    void
+     */
+    function MoodleQuickForm_advcheckbox($elementName=null, $elementLabel=null, $text=null, $attributes=null, $values=null)
+    {
+        $this->MoodleQuickForm_checkbox($elementName, $elementLabel, $text, $attributes);
+        $this->setValues($values);
+    } //end constructor
+
+    // }}}
+    // {{{ getPrivateName()
+
+
+
+    // {{{ setValues()
+
+    /**
+     * Sets the values used by the hidden element
+     *
+     * @param   mixed   $values The values, either a string or an array
+     *
+     * @access public
+     * @return void
+     */
+    function setValues($values)
+    {
+        if (empty($values)) {
+            // give it default checkbox behavior
+            $this->_values = array('', 1);
+        } elseif (is_scalar($values)) {
+            // if it's string, then assume the value to
+            // be passed is for when the element is checked
+            $this->_values = array('', $values);
+        } else {
+            $this->_values = $values;
+        }
+        $this->updateAttributes(array('value' => $this->_values[1]));
+        $this->setChecked($this->_currentValue == $this->_values[1]);
+    }
+
+    // }}}
+    // {{{ setValue()
+
+   /**
+    * Sets the element's value
+    *
+    * @param    mixed   Element's value
+    * @access   public
+    */
+    function setValue($value)
+    {
+        $this->setChecked(isset($this->_values[1]) && $value == $this->_values[1]);
+        $this->_currentValue = $value;
+    }
+
+    // }}}
+    // {{{ getValue()
+
+   /**
+    * Returns the element's value
+    *
+    * @access   public
+    * @return   mixed
+    */
+    function getValue()
+    {
+        if (is_array($this->_values)) {
+            return $this->_values[$this->getChecked()? 1: 0];
+        } else {
+            return null;
+        }
+    }
+
+    // }}}
+    // {{{ toHtml()
+
+    /**
+     * Returns the checkbox element in HTML
+     * and the additional hidden element in HTML
+     *
+     * @access    public
+     * @return    string
+     */
+    function toHtml()
+    {
+        if ($this->_flagFrozen) {
+            return parent::toHtml();
+        } else {
+            return '<input' . $this->_getAttrString(array(
+                        'type'  => 'hidden',
+                        'name'  => $this->getName(),
+                        'value' => $this->_values[0]
+                   )) . ' />' . parent::toHtml();
+
+        }
+    } //end func toHtml
+
+    // }}}
+    // {{{ getFrozenHtml()
+
+   /**
+    * Unlike checkbox, this has to append a hidden input in both
+    * checked and non-checked states
+    */
+    function getFrozenHtml()
+    {
+        return ($this->getChecked()? '<tt>[x]</tt>': '<tt>[ ]</tt>') .
+               $this->_getPersistantData();
+    }
+
+    // }}}
+    // {{{ onQuickFormEvent()
+
+    /**
+     * Called by MoodleQuickForm whenever form event is made on this element
+     *
+     * @param     string    $event  Name of event
+     * @param     mixed     $arg    event arguments
+     * @param     object    $caller calling object
+     * @since     1.0
+     * @access    public
+     * @return    void
+     */
+    function onQuickFormEvent($event, $arg, &$caller)
+    {
+        switch ($event) {
+            case 'updateValue':
+                // constant values override both default and submitted ones
+                // default values are overriden by submitted
+                $value = $this->_findValue($caller->_constantValues);
+                if (null === $value) {
+                    $value = $this->_findValue($caller->_submitValues);
+                    if (null === $value) {
+                        $value = $this->_findValue($caller->_defaultValues);
+                    }
+                }
+                if (null !== $value) {
+                    $this->setValue($value);
+                }
+                break;
+            default:
+                parent::onQuickFormEvent($event, $arg, $caller);
+        }
+        return true;
+    } // end func onQuickFormLoad
+
+    // }}}
+    // {{{ exportValue()
+
+   /**
+    * This element has a value even if it is not checked, thus we override
+    * checkbox's behaviour here
+    */
+    function exportValue(&$submitValues, $assoc)
+    {
+        $value = $this->_findValue($submitValues);
+        if (null === $value) {
+            $value = $this->getValue();
+        } elseif (is_array($this->_values) && ($value != $this->_values[0]) && ($value != $this->_values[1])) {
+            $value = null;
+        }
+        return $this->_prepareValue($value, $assoc);
+    }
+    // }}}
+} //end class MoodleQuickForm_advcheckbox
+?>