HTTP forms defined in YAML

This module allows creating simple interfaces to forms/payloads for use in HTTP POST requests by defining them in highly readable and easily maintainable YAML files.

Form definition

A form is defined by its fields.

A field is defined by an alias (for internal use) and the field's name, which is the parameter name in the payload sent during a POST request, and which typically corresponds to the name attribute of a <select> or <input> HTML tag.

Optionally, a field can have a default value, value options (as <select> tags do), and may be declared required (i.e. non-optional).

A form definition in YAML format will consist of the field aliases as top-level keys, and the corresponding fields' definitions as key-value-pairs below them.

Example

Definition

# definition.yaml

field1:
  name: payload_param_1
field2:
  name: payload_param_2
  default: foo
choice_field:
  name: payload_param_3
  options:
    value1: text for option 1
    value2: text for option 2
  default: value1
mandatory_field:
  name: payload_param_0
  required: true

Usage

>>> from yamlhttpforms import load_form
>>> form_interface = load_form('definition.yaml')
>>> form_interface.get_payload(field1='abc', field2='bar', mandatory_field='420')
{'payload_param_1': 'abc', 'payload_param_2': 'bar', 'payload_param_3': 'value1', 'payload_param_0': '420'}
>>> form_interface.get_payload(field1='abc', choice_field='baz', mandatory_field='420')
Traceback (most recent call last):
  ...
ValueError: "baz" is not a valid option for <SelectField: name="payload_param_3", default="value1", options={'value1': 'text for option 1', 'value2': 'text for option 2'}>