What happened?

1. Define a form XML containing a meter field with custom min and max attributes (for example min="10", max="50", value="30"):

<field
    name="my_meter"
    type="meter"
    label="Usage Meter"
    min="10"
    max="50"
    value="30"
/>

2. Load and render the field using Joomla Form:

$form = new \Joomla\CMS\Form\Form('test');
$form->load('<form><field name="my_meter" type="meter" label="Usage Meter" min="10" max="50" value="30" /></form>');
$field = $form->getField('my_meter');
echo $form->getInput('my_meter');

3. Inspect the rendered HTML markup or inspect $field->min and $field->max.

Version

5.4

Expected result

1. MeterField::setup() reads min and max from the XML element attributes ($this->min = 10, $this->max = 50).
2. $field->min and $field->max return 10 and 50.
3. The rendered progress bar outputs aria-valuemin="10", aria-valuemax="50", aria-valuenow="30", and width calculated as 50% ((30 - 10) * 100 / (50 - 10)).

Actual result

1. MeterField::setup() ignores min and max XML attributes, leaving $this->min hardcoded to 0 and $this->max hardcoded to 100.
2. MeterField::__get() does not handle min and max, returning null when accessing $field->min or $field->max.
3. The rendered progress bar outputs aria-valuemin="0", aria-valuemax="100", and width 30% ((30 - 0) * 100 / (100 - 0)).

System Information

• Joomla 5.4-dev / 6.0-dev
• PHP 8.1 / 8.2 / 8.3 / 8.4 / 8.5
• Any OS / Web server

Additional Comments

In libraries/src/Form/Field/MeterField.php:

1. In setup(), attributes width, color, active, and animated are extracted from $this->element, but min and max are omitted:

if ($return) {
    $this->width = isset($this->element['width']) ? (string) $this->element['width'] : '';
    $this->color = isset($this->element['color']) ? (string) $this->element['color'] : '';
    // $this->min and $this->max are never extracted

2. In __get(), min and max are missing from the switch statement (even though they are present in __set()):

public function __get($name)
{
    switch ($name) {
        case 'active':
        case 'width':
        case 'animated':
        case 'color':
            return $this->$name;
    }

    return parent::__get($name);
}

Adding min and max extraction in setup() and handling them in __get() resolves the issue.