newforms

A JavaScript port of Django's form-handling library, which runs in browsers in Node.js

• Fragile - use of newforms and ModelChoiceField in Sacrum
• Demo page
• QUnit tests

Install

Node.js:

npm install newforms

Browser bundles (all dependencies included):

• newforms.js - 232KB (54KB gzipped)
• newforms.min.js - 83.9KB (23.4KB gzipped)

Browser bundles currently expose:

• newforms as a forms variable.
• a require() function which can be used to access bundled dependencies:
  • Concur - sugar for inheritance
  • DOMBuilder - interchangeable DOM Element / HTML generation
  • isomorph - miscellaneous utilities

Documentation (WIP)

http://newforms.readthedocs.org

Usage

As direct porting from Django is nearing completion, the resulting API is very much focused on the server side. As such, Node.js is probably the best place to use newforms in anger at the moment, as you'll be working with a request/response cycle, which is Django forms' usual mode of operation.

Client side features, such as hooking into the DOM for instant validation and feedback, will be the focus of future work.

In lieu of guide documentation, head over to the Django forms documentation for a quick overview of the concepts behind this form library.

Here's a quick guide to getting started with newforms.

• For Node.js, if you clone this repo and install express and jade via npm, you can run node demo/demo.js to see a basic example of newforms in action.

  All example code will assume you've imported like so:

  var forms = require('newforms')
  

• For convenience and compactness, the new operator is optional when using newforms' Fields, Widgets and other constructors which are commonly used while defining a Form, such as ValidationError -- however new is not automatically optional for the Form and FormSet constructors you create.

• Form constructors are created using the forms.Form constructor's extend() function, which comes courtesy of Concur. This takes an Object argument defining form fields and any other properties for the form's prototype (validation methods etc.), returning a constructor which inherits from BaseForm:

  var ContactForm = forms.Form.extend({
    subject  : forms.CharField({maxLength: 100})
  , message  : forms.CharField()
  , sender   : forms.EmailField()
  , ccMyself : forms.BooleanField({required: false})
  })
  
  var form = new ContactForm()
  

• FormSet constructors are created using the forms.formsetFactory function, which takes a Form constructor and any additional properties for the FormSet's prototype defined as an Object, returning a FormSet constructor which inherits from BaseFormSet:

  var ArticleForm = forms.Form.extend({
    title   : forms.CharField()
  , pubDate : forms.DateField()
  })
  
  var ArticleFormSet = forms.formsetFactory(ArticleForm, {extra: 1})
  
  var formSet = new ArticleFormSet()
  

• Custom row styling: requiredCssClass and errorCssClass can be added to any form and the classes will be applied to each matching row in the form output. To add extra CSS classes to a particular row, pass the extraClasses property in the field definition. All of the above are added to the class attribute of the containing element, e.g., <tr>, <li> or <p>:

  var PostForm = forms.Form.extend({
  // Fields
    postTitle        : forms.CharField({maxLength: 100})
  , postBody         : forms.CharField({extraClasses: 'larger island'})
  , allowComments    : forms.BooleanField({required: false})
  // CSS settings
  , requiredCssClass : 'required'  // A class to style required fields
  , errorCssClass    : 'error'     // A class to style fields with errors
  })
  

• The API is largely consistent with Django's API, with the following rules of thumb for converting between the two:

  • Where Django accepts keyword arguments, in Javascript a single Object argument is expected, with arguments expressed as its properties.

    Note that this applies anywhere Django accepts a keyword argument, even if the convention in Django is topass certain keyword arguments positionally, e.g. when passing in POST data to a Form constructor.

    Django (by convention):

    f = MyForm(request.POST)
    

    Javascript:

    var f = new MyForm({data: req.body})
    

  • Method and variable names which use underscores_in_python become camelCasedInJavaScript.

  • As mentioned above, the new operator is optional for newforms form components.

    Django:

    forms.CharField(max_length=100)
    

    JavaScript (the following lines are equivalent):

    new forms.CharField({maxLength: 100})
    forms.CharField({maxLength: 100})
    

  • Due to limited cross-browser support for properties in JavaScript, Form and FormSet properties from Django such as cleaned_data and errors become method calls; e.g. cleanedData() and errors().

    It's ugly, but it works everywhere.

  • Objects which would be coerced to a string for display in Django, such as Forms, FormSets and ErrorLists, have a defaultRendering() method.

    This is required because newforms can output DOM Elements or HTML from the same objects and there's no standard toDOM()-type method in JavaScript. If you're operating in HTML mode, you can coerce these objects to string to get HTML out of them, as their toString() methods make use of defaultRendering().

The unit tests exercise the library thoroughly, so dip in for examples of further usage in the meantime.

MIT License

Copyright (c) 2011, Jonathan Buchanan

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.