compose-form-up

FormUp

A lightwight form utlitiy module.

Validation

FormUp enhances HTML5's form validation, adding valid and invalid classes as the form is completed, and handling custom messages with a bit more finesse.

Automatic validation

FormUp can watch for form submission events and stop them and style invalid inputs, and add messages if the form is invalid. This will also watch for input changes and update validation styles when the user interacts.

Here's what that looks like.

var formUp = require( 'compose-form-up' )

Whenever submit is triggered on a form, validation will automatically run, handling messages and styles.

validate( form ) - Manual Validation

This component works best automatically, but if for some reason you have to manually trigger validation, you'd do this.

var formUp = require( 'compose-form-up' )
var form = document.querySelector( '#your-form' )

if ( formUp.validate( form ) ) {
  // Form is valid  
} else {
  // Form is not valid
}

Here, formUp.validate( form ) will return true or false based on the forms validity. It will set custom messages and style invalid inputs. However, to clear invalid styles you'll need to run this any time a form element is updated.

Custom Validation Messages

Inputs can have custom validation messages with the data-message attribute.

This input uses the pattern attribute to check for a valid email address and then the data-message attribute to use a custom message if the field is invalid.

<input type="email" pattern="([^@]+@[^@]+\.[a-zA-Z]{2,}|)"
data-message="Please enter a valid email address."
required="required" value="">

Custom Validation helpers

• data-max-words="3" - Ensure no more than 3 words are entered.
• data-min-words="3" - Ensure at least 3 words are entered.
• data-invalid-value="superman" - Superman cannot be entered.
• data-invalid-value-message="Invalid value: superman" - Sets a custom error message when a value matching the data-invalid-value is set.

Using invalidateField you can easily invalidate a field's current value.

formUp.invalidateField( element, [message] )

For example if you find a usename is already taken, you could invalidate the username field like this.

var username = document.querySelector( 'input[name=username]' )
formUp.invalidateField( username, "Username: " + username.value + " is taken. ")

Progressive Forms

A progressive form will show one fieldset at a time. Each time a submit event is triggered, the active fieldset will transition away (assuming there are no validation errors), and the next fieldset will appear. Once all fieldsets are complete, the form will submit as usual. You can also register a callback to be triggered at the point of each transition, to call some scrip before continuing (like an ajax call or whatever).

Here's what a simple progressive form may look like.

<form id="some-form" class="progressive">

  <fieldset class="form-step">
    <!-- Some inputs -->
    <button type='submit'>Submit</button>
  </fieldset>

  <fieldset class="form-step">
    <!-- Some more inputs -->
    <button type='submit'>Submit</button>
  </fieldset>

</form>

Styling fieldsets

To help with styling form steps (with transitions) these classnames are added to fieldsets to show state.

active    - the current step
enter     - When a step transitions in
exit      - When a step is being dismissed
completed - When a step has been filled out

Also data-direction attributes describe the direction of a transition. So you could style transitions in and out like this:

/* Enter animations */
.form-step.enter[data-direction=forward] { /* enter stage right */ }
.form-step.enter[data-direction=reverse] { /* enter stage left */ }

/* Exit animations */
.form-step.exit[data-direction=forward] { /* exit stage left */ }
.form-step.exit[data-direction=reverse] { /* exit stage right */ }

Handling the next event

var formUp = require( 'compose-form-up' )

var form = document.querySelector( '#some-form' )

formUp.next( form, function( event, step ) {

  // event is the submission event

  // step.forward() - go to the next step
  // step.dismiss() - leave the current step
  // step.revisit() - used after dismiss, return to a dismissed step (for example: to deal with an ajax error)
  // step.fieldset  - reference the current fieldset element
  // step.form      - reference to the current form element
  // step.complete  - true/false - is this the last step?
  // step.formData  - formData object for the current fieldset ( handy for ajax )

  // Example ajax
  ajax.post( '/users' )
    .send( step.formData )
    .end( function( err, response ) {

      if (!err) step.forward()  // go to the next fielset
      else      step.back()     // return to current fieldset

    })

})

Fieldset Navigation

To add navigation to your progressive form, add data-nav=true to the form element.

Note: Users cannot use the navigation to advance forward through fieldsets witout submitting the forms. This navigation exists to allow users to revisit any fieldset and update its information. Users can navigate to any fieldset which has been filled out and submitted, or navigate back to the current step.

Here's an example a form with navigation

<form id="some-form" class="progressive" data-nav='true'>

  <fieldset class="form-step" data-nav='1. Create Account'>
    <!-- Some inputs -->
    <button type='submit'>Submit</button>
  </fieldset>

  <fieldset class="form-step" data-nav='2. Enter Payment'>
    <!-- Some more inputs -->
    <button type='submit'>Submit</button>
  </fieldset>

</form>

Each fieldset can set the title for the navigation with the data-nav element.

This will generate navigation with this HTML:

<nav class='progressive-form-nav'>
  <a href="#" data-step='1'>1. Create Account</a>
  <a href="#" data-step='2'>2. Enter Payment</a>
</nav>

Styling nav items

Nav items will receive classes based on their state. You can use these to style them appropriately.

here      - The current step
next      - All steps after the current step
previous  - All steps before the current step
completed - Any step which has been submitted (this includes current and next steps if a user has navigated back)