Allow custom name for Field

[toptalo]

Hello!

I have a custom submission hook that posts form data to external API.
This API has its own field names defined and I need possibility to control form fields names.

For that purpose I have added neme CharBlock to blocks.StructBlock in get_form_block method of BaseField in wagtailstreamforms_fields.py

I do that, because I found class method get_formfield_name() in source code that trys to get field name from block value

After that I have redefine form fields names, save form config and submit my form.

Than on submissions page I have see, that all new submissions displays with None value.

This was happend because in method get_data_fields field name is a slug generated from label, without checking field["value"]["name"] as was done in get_formfield_name method

So I have suggest to modify this method to respect field name value like so:

(field["value"]["name"] or get_slug_from_string(field["value"]["label"])

    def get_data_fields(self):
        """Returns a list of tuples with (field_name, field_label)."""

        data_fields = [("submit_time", _("Submission date"))]
        data_fields += [
            (field["value"]["name"] or get_slug_from_string(field["value"]["label"]), field["value"]["label"])
            for field in self.get_form_fields()
        ]
        if getattr(settings, "WAGTAILSTREAMFORMS_SHOW_FORM_REFERENCE", False):
            data_fields += [("form_reference", _("Form reference"))]
        return data_fields

What dou you think?
I can make PR for that

[rgs258]

@toptalo , I think my branch (and PR) https://github.com/labd/wagtailstreamforms/pull/160/files#diff-951d949d800424b6334469000bf4a47f1841b3fe5b59b25b81d07a779d9a3c11R65 might address your needs. I wonder if that's correct?

[toptalo]

@rgs258
You mean that I can override method create_field_name with my own, that will return value of field["value"]["name"]??

[toptalo]

Also, have a look into get_data_fields method of wagtailstreamforms/models/form.py

This method must use same logic of getting field name as in wagtailstreamforms/forms.py but for now it only use slug from label
(create_field_name)

That is a point of my Issue - in different places field name makes in different ways