Lift Cookbook

Chapter 3. Forms Processing in Lift

This chapter looks at how to process form data with Lift: submitting forms, working with form elements. The end result of a form submission can be records being updated in a database, so you may also find Chapter 7 or Chapter 8 useful, as they discuss relational databases and MongoDB, respectively.

To the extent that form processing is passing data to a server, there are also recipes in Chapter 5 that are relevant to form processing.

You’ll find many of the examples from this chapter as source code at https://github.com/LiftCookbook/cookbook_forms.

Plain Old Form Processing

Problem

You want to process form data in a regular, old-fashioned, non-Ajax way.

Solution

Extract form values with S.param, process the values, and produce some output.

For example, we can show a form, process an input value, and give a message back as a notice. The template is a regular HTML form, with the addition of a snippet:

<form data-lift="Plain" action="/plain" method="post">
  <input type="text" name="name" placeholder="What's your name?">
  <input type="submit" value="Go">
</form>

In the snippet, we can pick out the value of the field name with S.param("name"):

package code.snippet

import net.liftweb.common.Full
import net.liftweb.http.S
import net.liftweb.util.PassThru

object Plain {

  def render = S.param("name") match {
    case Full(name) =>
      S.notice("Hello "+name)
      S.redirectTo("/plain")
    case _ =>
      PassThru
  }

}

The first time through this snippet, there will be no parameter, so we just ...