Using the Taglib

Advantages

The FormEngine comes with a small tag library for initializing and rendering forms.

The FormEngine tag library offers the following advantages:

Use the FormEngine in web frameworks (i. e JSF, Spring), within other taglibs und JSPX templates which do not allow using scripting code.
Integrate and combine the tag library together with other tag libraries as JSTL and use the JSP Expression Language (EL) in your consistent Java EE web application.
Clean separation between logic and view

Declaration

For embedding a form in your page you need two taglib declarations. The first is the FormEngine tag library, the second is a taglib to embed all JavaScript and CSS resources needed by the form.

<%@ taglib prefix="fe" uri="http://www.imatics.de/forms" %>
<%@ taglib prefix="imx" uri="http://www.imatics.de/j2ee" %>

Initializing a form instance

The fe:load-form tag is used to initialize a form instance and to set the instance as an attribute to any scope (attributes var and scope).

The tag fe:load-form only supports providing an URL based form definition (URL to an XML file with attribute resourcePath).

Via embedded fe:runtime-param tags you can provide runtime parameters for the form instance. You can set a connector (attribute connector) or the data for a connector defined in the form definition (attribute connectorData) as well.

<fe:load-form resourcePath="/path/to/my/form.xml" var="form"
    connectorData="${param['id']}">
  <fe:runtime-param name="myParamName" value="${myParamValueVar}"/>
</fe:load-form>

Printing the HTML Resources

After initializing the form all JavaScript and CSS resources must be printed in the HTML head area. This is easily done with the tag imx:print-request-includes.

Rendering the Form

Now the initialized form can be rendered in the HTML body with the help of fe:render-form.

<html>
<head>
  <imx:print-request-includes/>
</head>

<body>
   <fe:render-form form="${form}"/>
</body>
</html>