caolan / forms

An easy way to create, parse and validate forms in node.js
MIT License
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Constructing a good form by hand is a lot of work. Popular frameworks like Ruby on Rails and Django contain code to make this process less painful. This module is an attempt to provide the same sort of helpers for node.js.

$ npm install forms

Contribute

This code is still in its infancy, and I'd really appreciate any contributions, bug reports, or advice. Especially on the following key areas:

Example

Creating an example registration form:

var forms = require('forms');
var fields = forms.fields;
var validators = forms.validators;

var reg_form = forms.create({
    username: fields.string({ required: true }),
    password: fields.password({ required: validators.required('You definitely want a password') }),
    confirm:  fields.password({
        required: validators.required('don\'t you know your own password?'),
        validators: [validators.matchField('password')]
    }),
    email: fields.email()
});

Rendering a HTML representation of the form:

reg_form.toHTML();

Would produce:

<div class="field required">
    <label for="id_username">Username</label>
    <input type="text" name="username" id="id_username" value="test" />
</div>
<div class="field required">
    <label for="id_password">Password</label>
    <input type="password" name="password" id="id_password" value="test" />
</div>
<div class="field required">
    <label for="id_confirm">Confirm</label>
    <input type="password" name="confirm" id="id_confirm" value="test" />
</div>
<div class="field">
    <label for="id_email">Email</label>
    <input type="text" name="email" id="id_email" />
</div>

You'll notice you have to provide your own form tags and submit button, its more flexible this way ;)

Handling a request:

function myView(req, res) {
    reg_form.handle(req, {
        success: function (form) {
            // there is a request and the form is valid
            // form.data contains the submitted data
        },
        error: function (form) {
            // the data in the request didn't validate,
            // calling form.toHTML() again will render the error messages
        },
        empty: function (form) {
            // there was no form data in the request
        }
    });
}

That's it! For more detailed / working examples look in the example folder. An example server using the form above can be run by doing:

$ node example/simple.js

Bootstrap compatible output

For integrating with Twitter bootstrap 3 (horizontal form), this is what you need to do:

var widgets = require('forms').widgets;

var my_form = forms.create({
    title: fields.string({
        required: true,
        widget: widgets.text({ classes: ['input-with-feedback'] }),
        errorAfterField: true,
        cssClasses: {
            label: ['control-label col col-lg-3']
        }
    }),
    description: fields.string({
        errorAfterField: true,
        widget: widgets.text({ classes: ['input-with-feedback'] }),
        cssClasses: {
            label: ['control-label col col-lg-3']
        }
    })
});

var bootstrapField = function (name, object) {
    if (!Array.isArray(object.widget.classes)) { object.widget.classes = []; }
    if (object.widget.classes.indexOf('form-control') === -1) {
        object.widget.classes.push('form-control');
    }

    var label = object.labelHTML(name);
    var error = object.error ? '<div class="alert alert-error help-block">' + object.error + '</div>' : '';

    var validationclass = object.value && !object.error ? 'has-success' : '';
    validationclass = object.error ? 'has-error' : validationclass;

    var widget = object.widget.toHTML(name, object);
    return '<div class="form-group ' + validationclass + '">' + label + widget + error + '</div>';
};

And while rendering it:

reg_form.toHTML(bootstrapField);

Available types

A list of the fields, widgets, validators and renderers available as part of the forms module. Each of these components can be switched with customised components following the same API.

Fields

Widgets

Validators

Renderers

API

A more detailed look at the methods and attributes available. Most of these you will not need to use directly.

forms.create(fields)

Converts a form definition (an object literal containing field objects) into a form object.

forms.create(fields, options)

Forms can be created with an optional "options" object as well.

Supported options:

Form object

Attributes

form.handle(req, callbacks)

Inspects a request or object literal and binds any data to the correct fields.

form.bind(data)

Binds data to correct fields, returning a new bound form object.

form.toHTML(iterator)

Runs toHTML on each field returning the result. If an iterator is specified, it is called for each field with the field name and object as its arguments, the iterator's results are concatenated to create the HTML output, allowing for highly customised markup.

Bound Form object

Contains the same methods as the unbound form, plus:

Attributes

form.validate(callback)

Calls validate on each field in the bound form and returns the resulting form object to the callback.

form.isValid()

Checks all fields for an error attribute. Returns false if any exist, otherwise returns true.

form.toHTML(iterator)

Runs toHTML on each field returning the result. If an iterator is specified, it is called for each field with the field name and object as its arguments, the iterator's results are concatenated to create the HTML output, allowing for highly customised markup.

Field object

Attributes

field.choices

The choices property is used for radio, checkbox, and select fields. Two formats are supported and in case of select fields the format can be nested once to support option groups.

The first format is based on objects and is easy to write. Object keys are treated as values and object values are treated as labels. If the value is another object and nesting is supported by the widget the key will be used as label and the value as nested list.

The second format is array-based and therefore ordered (object keys are unordered by definition). The array should contain arrays with two values the first being the value and the second being the label. If the label is an array and nesting is supported by the widget the value will be used as label and the label as nested list.

Both formats are demonstrated below:

// objects
{
    'val-1': 'text-1',
    'val-2': 'text-2',
    'text-3': {
        'nested-val-1': 'nested-text-1',
        'nested-val-2': 'nested-text-2',
        'nested-val-3': 'nested-text-3'
    }
}

// arrays
[
    ['val-1', 'text-1'],
    ['val-2', 'text-2'],
    ['text-3', [
        ['nested-val-1', 'nested-text-1'],
        ['nested-val-2', 'nested-text-2'],
        ['nested-val-3', 'nested-text-3'],
    ]]
]

field.parse(rawdata)

Coerces the raw data from the request into the correct format for the field, returning the result, e.g. '123' becomes 123 for the number field.

field.bind(rawdata)

Returns a new bound field object. Calls parse on the data and stores in the bound field's data attribute, stores the raw value in the value attribute.

field.errorHTML()

Returns a string containing a HTML element containing the fields error message, or an empty string if there is no error associated with the field.

field.labelText(name)

Returns a string containing the label text from field.label, or defaults to using the field name with underscores replaced with spaces and the first letter capitalised.

field.labelHTML(name, id)

Returns a string containing a label element with the correct 'for' attribute containing the text from field.labelText(name).

field.classes()

Returns an array of default CSS classes considering the field's attributes, e.g. ['field', 'required', 'error'] for a required field with an error message.

field.toHTML(name, iterator)

Calls the iterator with the name and field object as arguments. Defaults to using forms.render.div as the iterator, which returns a HTML representation of the field label, error message and widget wrapped in a div.

Bound Field object

same as field object, but with a few extensions

Attributes

validate(callback)

Checks if the field is required and whether it is empty. Then runs the validator functions in order until one fails or they all pass. If a validator fails, the resulting message is stored in the field's error attribute.

Widget object

Attributes

toHTML(name, field)

Returns a string containing a HTML representation of the widget for the given field.

Validator

A function that accepts a bound form, bound field and a callback as arguments. It should apply a test to the field to assert its validity. Once processing has completed it must call the callback with no arguments if the field is valid or with an error message if the field is invalid.

Renderer

A function which accepts a name and field as arguments and returns a string containing a HTML representation of the field.