Formbar

Formbar is a python library to layout, render and validate HTML forms in web applications. Formbar renders forms which are compatible with Twitter Bootstrap styles.

Formbar is the German word for "shapeable" and should emphasise the character of formbar which hopefully makes shaping your forms more easy.

In contrast to many other form libraries forms with formbar are configured in XML files to separate the form definition from the implementation and handle it as configuration.

Formbar is production ready and already used in applications with large forms.

Licence

Formbar is Free Software and licensed under GPL version >= 2.

Documentation

Online documentation can be found at formbar.readthedocs.org

Features

• Conversion between Python values and value in the form and vice versa.
• i18n support for labels and texts in the form.
• Conditional fields in the form. E.g Render fields readonly if other fields have a certain value.
• Flexible form definition and layout.
  • Different form layouts for the same model (Create, Edit, Read...)
  • Support for inheritance and including parts of other forms.
  • Support for different pages, sections and subsections.
• Styling
  • Twitter bootstrap support
  • Row and column based layouts
  • Custom CSS styling
  • Numbering of fields
  • XML based form definition
  • Help texts
• Validation:
  • Basic datatype validation on conversion for different types of data (date, int, float, email...).
  • Rule based validation in the form using expressions (brabbel).
  • Error and warning messages
• Expandable
  • Support for external renderers
  • Support for writing external validators
• Support for SQLAlchemy mapped items and plain forms

Getting started

Please refer to formbar documentation for further information how to get started using formbar. For all the impatient out there here comes a very comprehensive example code which should give a glimpse on how things could work for you:

from formbar.config import Config, load
from formbar.form import Form
# Simple rendering here, no data submission
# nor validation or saving.
config = Config(load('/path/to/formconfig.xml'))
form_config = config.get_form('example')
form = Form(form_config)
form.render()

The corresponding configuration file might look like this one.:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<configuration>
  <source>
    <!-- Define different entity types -->
    <entity id="e1" name="float" label="Float field" type="float">
      <rule expr="$float lt 100" msg="Float must be lower than 100" mode="post"/>
      <help>This is is a very long helptext which should span over
      multiple rows. Further the will check if there are further html
      tags allowed.</help>
    </entity>
    <entity id="e2" name="select" label="Select field" type="string">
      <help>This is my helptext</help>
      <options>
        <option value="1">Option 1</option>
        <option value="2">Option 2</option>
        <option value="3">Option 3</option>
        <option value="4">Option 4</option>
      </options>
    </entity>
  </source>
  <!-- The entities are finally only referenced to layout the form -->
  <form id="example1" css="testcss" autocomplete="off" method="POST" action="" enctype="multipart/form-data">
    <row>
      <col><field ref="e1"/></col>
    </row>
    <row>
      <col><field ref="e2"/></col>
    </row>
  </form>
</configuration>

This is a very simple example just to get an impression. There are many more configuration options. See the examples folder for more information on the configuration or how the validation works.