How to generate a dynamic note field for a custom component?

Question

I am attempting to develop my first custom component called com_image. Because of the structure and function of my project requirements, it made best sense to clone the com_contact folder and duplicate the necessary db tables/rows. I commented out lots of unnecessary structure from the component, but now I need to add something in.

How can I generate a blue/info note for the "Edit Image" (first) tab at administrator/index.php?option=com_image&view=image&layout=edit&id=1 ?

For my project, there are actually no fields in the primary panel of the first tab. The note field only needs to hold the location value which I am successfully echoing with...

<div class="row-fluid">
    <div class="span9">
        <div class="row-fluid form-horizontal-desktop float-cols" >
            <div class="span12">
                <?php echo "Path: <b>" , $this->item->location , "</b><br>"; ?>
                <?php echo "<img src=\"" , $this->item->location , "\">"; ?>
            </div>
        </div>
    </div>
    <div class="span3">
        <?php echo JLayoutHelper::render('joomla.edit.global', $this); ?>
    </div>
</div>

I don't know how to make $this->form->renderField(); work for me.

I read https://docs.joomla.org/Creating_a_custom_form_field_type/en but this only solves half of the problem.

I'd like to deliver this component with attention to mise en place for my own education -- so please only suggest best practices.

To be more specific:

Do I create a new .php file in com_image/models/fields so that I can extend JFormFieldNote? If so, how do I pass my $this->item->location value to getLabel()? And how to do I call the new custom note back from edit.php? I don't want to modify com_image/config.xml, right?

Current screenshot:

I think GDP's answer is not quite right for my purpose: How can I dynamically generate a form's XML from PHP?

This isn't it: Custom 'dynamic' form field creation

I reckon this is pretty close: Passing Arguments for custom field

p.s. If there is a better way to deal with the image element, I'd be happy to hear that too.

Answer 1

Use Form::setFieldAttribute(). Typically, this is done in the model's getForm() method. However, if it's cosmetic only, it can be done in the view too.

In /administrator/com_image/models/forms/image.xml (outside of a <fieldset> is fine):

<field
    name="myNote"
    type="note"
    class="alert alert-info"
/>

In /administrator/com_image/views/image/view.html.php (just before $this->addToolbar();):

$this->form->setFieldAttribute('myNote', 'label', $this->item->location);

In /administrator/com_image/views/image/tmpl/edit.php:

echo $this->form->renderField('myNote');

---

To create a field without editing XML file:

$note = new \SimpleXMLElement('<field />');
$note->addAttribute('name', 'myNote');
$note->addAttribute('type', 'note');
$note->addAttribute('label', $this->item->location);
$note->addAttribute('class', 'alert alert-info');
$this->form->setField($note);