wagtail-jsonschema-forms 0.1

Generate JsonSchema Forms from Wagtail's forms and validate it

Wagtail JsonSchema Forms is a simple Django app to Generate JsonSchema Forms from Wagtail’s forms and validate it.

This app allows the generation of a JsonSchema form from a Wagtail’s form in order to use JsonSchema technology. In addition, it allows you to parse the response and validate it. After the validation, the wagtail form is submitted.

For example, you can retrieve the jsonschema from through an api, then validate the submitted data and finally submit de wagtail form.

Installation

You can install “wagtail_jsonschema_forms” via pip from APSL GitHub:

• pip install git+https://github.com/APSL/wagtail_jsonschema_forms.git#egg=wagtail_jsonschema_forms

And then you have to add wagtail_jsonschema_forms to your INSTALLED_APPS.

Utilities provided

This app offers two python classes to generate the jsonschema and to submit the json response.

JsonSchemaGenerator

This first class has a method wagtail_form_to_json_schema that goes over all the fields of the form and generate its jsonschema representation, if they are suported.

Every suported field type has a method that generate the representation, which is called during the generation. If the field is required, it will be indicated too.

JsonSchemaParser

This second class provides two main methods:

• validate_json:

  method that validates the json recieved under the schema a return a dict with the possible errors. If there are no error, a empty dict will be returned.

• process_form_submission:

  method that accepts form instance with submitted data and page and creates submission instance. Inside of this method, another one is called to format the data submited in order to create the submission instance.

Usage

As was explained before, this django app generates jsonschema forms from Wagtail’s form and validate it. Wagtail’s forms offers a very rich set of form field types. However, not all of them are suported on JsonSchema and has not been covered on this app. For that reason, when you declare your FormField class on your models.py you should override the field_type field and the FORM_FIELD_CHOICES variable:

FORM_FIELD_CHOICES = (
    ('singleline', _('Single line text')),
    ('multiline', _('Multi-line text')),
    ('email', _('Email')),
    ('number', _('Number')),
    ('url', _('URL')),
    ('checkbox', _('Checkbox')),
    ('dropdown', _('Drop down')),
    ('date', _('Date')),
    ('datetime', _('Date/time')),
  )

field_type = models.CharField(verbose_name=_('field type'), max_length=16, choices=FORM_FIELD_CHOICES)

There are two ways to use wagtail_json_schema_forms: you can choose between using the mixins or the abstract models provided.

Mixins

If you choose to use the mixins, the first thing thant you have to do is to add a new TextField atribute to your wagtail form page called ‘json_schema’. This field will be used to save the JsonSchema representation of the form.

Two mixins are provided: JsonSchemaFormMixin and JsonSchemaEmailFormMixin, which inherit from the first one.

JsonSchemaFormMixin overrides the save method in order to generate the json schema before every time the wagtail page is saved. This mixin uses the generator class explained above to prepare the jsonschema from the form.

It’s also overrided the method process_form_submission, where it’s checked if the form has been submited as a usual wagtail form or using jsonschema. If jsonschema has been used for submition, the parser class is used to register the form submission.

As said, the JsonSchemaEmailFormMixin inherits from JsonSchemaFormMixin. The diference between them is in the process of the form submission. This second mixin tries to send an email after the form submission, if the to_address attribute of the wagtail page has been filed.

Abstract Models

Again, there are two abstract models provided to allow to add the jsonschema functionality to a plain WagtailForm and a EmailWagtailForm: AbstractJsonSchemaForm and AbstractJsonSchemaEmailForm.

These abstract models inherit from the mixins explained above and the AbstractForm or AbstractEmailForm. They also add the new TextField atribute required. Then, Wagtail Pages implementing a form that need to generate a JsonSchema (and to send and email) should inherit from it.

Contributing

Contributions are very welcome. Please open a pull request or file an issue. Tests will be ready as soon as posible, please ensure the coverage at least stays the same before you submit a pull request.

License

Distributed under the terms of the MIT license, “wagtail_jsonschema_forms” is free and open source software

Issues

If you encounter any problems, please file an issue along with a detailed description.