User:Frank Ralf/Semantic HTML5

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Read the whole story:

  1. Site Admin Block: "Look Ma, (nearly) no DIVs!"
  2. Site Admin Block: Better image placement
  3. Course Categories - The Ugly Duckling
  4. Course Categories - Clearing the Tables

Read the whole story on Moodle forms:

  1. Inconsistencies of Moodle forms
  2. formslib - Checkboxes: A case of "Divitis"? aka User:Frank Ralf/Semantic HTML5
  3. Moodle forms - A peek under the hood


formslib - checkboxes: A case of "Divitis"?

Working with forms proves a bit difficult due to the way formslib.php renders the individual form items. Let's look at a simple example (inspired by the General Developer forum discussion on "Interface design input please").

Example PHP

$mform->addElement('header', 'checkboxes', 'checkboxtest');
$mform->addElement(
  'checkbox',        // "type" attribute of input element
  'TEACHER',         // "name" attribute of input element
  'Mr. Smith',       // label to the left  
  'History',         // label to the right
  array('class'=>'pe_teacher', 'id'=> 'SMITH') // additional attributes     
  );
 
$mform->addElement(
  'checkbox',                 
  'teachers',  
  'Ms. Miller',
  'Math',                         
  array('class'=>'pe_teacher', 'id'=> 'miller') 
  );

Screenshots

That looks quite unsuspicious, but you might already see that the labels on the left and right side of the checkbox don't line up correctly:

Formslib checkboxes.png

So let's add some color by CSS to see the details. Tip: See Stylish for a tool to apply such helper CSS temporarily to your pages.

fieldset#checkboxes {background-color: yellow;}

legend              {background-color: lime;}
div.fcontainer      {background-color: blue;}
div.fitem           {background-color: red;}
div.fitemtitle      {background-color: silver;}
label               {background-color: aqua;}
div.felement        {background-color: teal;}
span                {background-color: orange;}
input.pe_teacher    {background-color: fuchsia; border: 3px dotted purple;}

Formslib checkboxes-colorful.png

With some margins and padding added by the following CSS it's becoming clearer:

fieldset#checkboxes * {margin: 5px; padding: 5px;}

Formslib checkboxes colorful-with-margins.png

Output HTML

So let's have a closer look at the markup Moodle provides (only first form item shown):

<fieldset class="clearfix" id="checkboxes">
  <legend class="ftoggler">Checkbox Test</legend>
  <div class="advancedbutton"></div>
  <div class="fcontainer clearfix">
    <div class="fitem">
      <div class="fitemtitle">
        <label for="id_SMITH">Mr. Smith </label>
      </div>
      <div class="felement fcheckbox">
        <span>
          <input class="pe_teacher" id="id_SMITH" name="TEACHER" value="1" type="checkbox">
          <label for="id_SMITH">History</label>
        </span>
      </div>
    </div>
	</div>
</fieldset>

What's the problem?

  • Given class ("pe_teacher") does have no visible effect at all.
  • Alignment issue with the two labels.
  • Makes DOM traversal with JavaScript difficult.
  • Possibly accessibility issues.
  • Our ID got an extra "id_" prepended (because we're overriding some automatically generated ID).
  • No inline elements (SPAN) allowed in form elements [?]
  • "ftitle" DIV only wraps label element
  • Two labels for the same form item
  • Default label to the left of the checkbox (right side recommended for accessibility reasons)

The culprit

The rendering of form elements is defined in formslib.php by the function MoodleQuickForm_Renderer() in the _elementTemplates variable ('default' =>):

<div class="fitem {advanced}
  <!-- BEGIN required --> required<!-- END required -->
  ">
  <div class="fitemtitle">
    <label>{label}
      <!-- BEGIN required -->{req}<!-- END required -->
      {advancedimg}{help}
    </label>
  </div>
  <div class="felement {type}
    <!-- BEGIN error --> error<!-- END error -->
    ">
    <!-- BEGIN error -->
      <span class="error">{error}</span>
      <br />
    <!-- END error -->
    {element}
  </div>
</div>

See also

Related forum discussions

Moodle Docs

Moodle Tracker

  • MDL-10505 "Add group name to rendered elements for better CSS control"
  • MDL-11134 "Help links in forms are outside the <label> - they will be ignored in JAWS forms mode"

Online resources