Add field override for bottom margin when field wrapper_class string contains variations on 'mb-' or 'my-' or 'm-'

[nordmichael]

Existing field template does not provide any mechanism for overriding bottom margin, leading to all form fields having a bottom margin of mb-3 even if a wrapper_class is specified that should replace mb-3

[nordmichael]

#218

[smithdc1]

Thanks for the patch.

I have spotted one regression that we should fix and then have a couple of suggestions.

We should also document this as it's likely to be a breaking change for some users. I'd add a release note.

[smithdc1]

This space that got removed is important.

If a layout were:

    test_form.helper.layout = Layout(
        Field('fruit', wrapper_class="custom-class")
    )

We now get:

<div id="div_id_fruit" class="mb-3custom-class">

It seems we don't have a test for this, we should add one.

[smithdc1]

We could use with to avoid many string concatenations.

Suggested change

<{% if tag %}{{ tag }}{% else %}div{% endif %} id="div_{{ field.auto_id }}" class="{% if field|is_checkbox and form_show_labels %}form-check{% else %}{% if wrapper_class and ' mb-' in ' '|add:wrapper_class or wrapper_class and ' my-' in ' '|add:wrapper_class or wrapper_class and ' m-' in ' '|add:wrapper_class %}{% else %}mb-3{% endif %}{% if 'form-horizontal' in form_class %} row{% endif %}{% endif %}{% if wrapper_class %}{{ wrapper_class }}{% endif %}{% if field.css_classes %} {{ field.css_classes }}{% endif %}">

<{% if tag %}{{ tag }}{% else %}div{% endif %} id="div_{{ field.auto_id }}" class="{% if field|is_checkbox and form_show_labels %}form-check{% else %}{% if wrapper_class %}{% with wc=' '|add:wrapper_class %}{% if ' mb-' in wc or ' my-' in wc or ' m-' in wc %}{% else %}mb-3{% endif %}{% endwith %}{% else %}mb-3{% endif %}{% if 'form-horizontal' in form_class %} row{% endif %}{% endif %}{% if wrapper_class %} {{ wrapper_class }}{% endif %}{% if field.css_classes %} {{ field.css_classes }}{% endif %}">

[smithdc1]

Add tests for the other options too?

Suggested change

	)
	Field('fruit', wrapper_class="custom-class"),
	Field('fruit', wrapper_class="m-4"),
	Field('fruit', wrapper_class="my-4"),
	Field('fruit', wrapper_class="my-4 custom-class"),
	)