What are the XForms and XPath?

**Nathen** · 03-03-2010

Hi friends,
I am an intermediate programmer and I have done with the C++, C# and the Core Java. Now I want to know about the XForms and the XPath. I have never heard this before in any programming language. So thought that posting here would be useful since you give the proper explanation for the queries. So please explain me what are the XForms and XPath? Need help as soon as possible.!!

**Solitario** · 03-03-2010

XForms : The two sections are used by the XForms to define data, which are :

XForms model
XForms user interface

You can say that the XForms model is an XML template which is used for the data.
XPath : XPath uses path expressions to identify nodes in an XML document. These path expressions look much like the expressions you see when you work with a computer file system.

**Deabelos** · 03-03-2010

When you use the XPath in the XForms, it usually contains a context node. Due to which the number of steps needed in the path expression are decreased. For example, if the instance data is a simple XHTML document :

HTML Code:

<html:html xmlns:html="http://www.techarena.in/2007/html">
  <html:head>
    <html:title>Global Warming Guidelines</html:title>
  </html:head>
  <html:body>
    <html:p>Save the Trees</html:p>
  </html:body>
</html:html>

the default context node is the element node named html:html.

**MindSpace** · 03-03-2010

You should keep in mind that you can change the default context node. Any element containing a binding expressions resets the context node for any child elements. XForms adopts the familiar XPath expression language. XPath was designed to be extensible both by users and implementers. Binding expressions include the ref attribute possibly with the model attribute, or alternatively the bind attribute. Languages such as XSLT, XQuery, XML Pointer Language (XPointer), XML Signature, and XForms that adopt the XPath expression language are expected to expand on this basic set with additional functions.

**kelfro** · 03-03-2010

XPath which is the XML Path Language can be said as query language for selecting nodes from an XML document. Within the markup for the XForms Model, there are a few things to be aware of regarding context nodes used for XPath expressions on the <bind> element. XPath may be used to compute values from the content of an XML document. You can also say that the XPath language is based on a tree representation of the XML document, and provides the ability to navigate around the tree, selecting nodes by a variety of criteria. The nodeset attribute on this element selects an XPath node-set, applying certain properties such as calculate to each node.

**CodGuru** · 03-03-2010

The following is an XHTML document containing a simple XForm, which would be very useful for you to understand the concepts :

HTML Code:

<html xmlns="URL goes here" 
    xmlns:xforms="URL / xforms">
   <head>
    <title>Date and Time</title>
    <xforms:model>
     <xforms:instance xmlns="">
      <Name/>
     </xforms:instance>
    </xforms:model>
   </head>
   <body>
    <h1>
      <xforms:output value="now()">
        <xforms:label>The time is now: </xforms:label>
      </xforms:output>
    </h1>
   </body>
</html>