Validation as you type in Lift

form.html

    <div>
      <form class="lift:InventoryCreate?form=post;multipart=true">
        <fieldset>
          <legend><span>Main Information</span></legend>
          <ol>
            <li><label for="part_number">Part Number</label>
              <input id="part_number" name="part_number" class="text" type="text" /><br>
              <p id="part_number_error" class=""></p>
            </li>
            <li><label for="description">Description:</label>
              <input id="description" name="description" size="80" class="text" type="text" /><br>
              <p id="description_error" class=""></p>
            </li>
            <li><label for="category">Category:</label>
              <input id="category" name="category"  class="text" type="text" />
            </li>
            <li><label for="sub_category">Sub Category:</label>
              <input id="sub_category" name="sub_category" class="text" type="text" />
            </li>
          </ol>
        </fieldset>
      </form>
    </div>

snippet.scala

class InventoryCreate extends Logger {

  object product extends RequestVar(Inventory.create)
  .... //many other objects here

  def render ={
  def process() ={  
    def validateField(errorFieldId: String, field: String, text: String) ={
      if(text.length < 2){
        <p class="error" id={errorFieldId}>{field} is too short</p>
      } else {
        <p class="success" id={errorFieldId}>Valid</p>
      }
    }


    def ajaxLiveText(value: String, func: String => JsCmd, attrs: (String, String)*): Elem = {
        S.fmapFunc(S.SFuncHolder(func)) {funcName =>
            (attrs.foldLeft(<input id="part_number"
            type="text"
            value=""
            onfocus="if (this.value == 'Enter part number') {this.value = '';}"
            onblur="if (this.value == '') {this.value = 'Enter part number';}"
            />)(_ % _)) %
                    ("onkeyup" -> makeAjaxCall(
                        JsRaw("'" +
                            funcName +
                            "=' + " +
                            "encodeURIComponent(this.value)")
                            )
                    )
        }
    }
    }

    "name=part_number"  #> ajaxLiveText("", x => Replace(
                           "part_number_error", validateField(
                               "part_number_error", "Part Number", x))) andThen
    "name=part_number"            #> SHtml.onSubmit(product.is.part_number.set(_)) &

    ....

}