Advantages of XForms
- XForms are device-independent: Once you have constructed an XForm, you can deploy it on every XForms-enabled device,
whether it be a web page in a browser, a PDA, or a cell phone. Essentially, you do not need to change anything in the XForm, as the device
itself takes care of the presentation.
A good number of browsers or browser plugins (for PCs and mobile devices) is already available for XForms.
- XForms separate content from presentation: As usually in XML technologies, XForms are about data, not about presentation.
However, XForms can be transformed in e.g. XHTML for presentation in a classic browser using an XSLT stylesheet.
- XForms have much more functionality than HTML forms: Suppose you have to fill in a date into an HTML form. If you send the
form to the server, the server has to check whether the date is in the right format, and whether what you have send is really a date.
In XForms the device itself takes care of checking, before sending the data !
- XForms can be dynamic: For example, in an eCRF, questions about pregnancy can be blanked out automaticically,
at the moment that a checkbox "Male" is checked on. Or, when loading the XForms, the questions about pregnancy are already blanked out when
the database states that the subject is male.
- XForms separate data from presention. The data and input fields themselves are in the XForms document, which is an XML or XHTML document,
whereas the presentation (styling, fonts, colors) is stored in a cascading stylesheet file (CSS). So, if you do not like the styling of the
page in the web page or PDA or cell phone, you just change or replace the CSS. This also means if you want to deploy on different devices, you
just take another CSS file, without actually touching the XForms document itself.
- XForms can be generated automatically e.g. from XML documents. In our example, we show how a CDISC ODM Study definition can be
automatically transformed (using XSL technology) into a set of XForms that can be deployed either in web browsers, in PDAs, or on cell phones.
This means that the tranformation stylesheet has to be developed only once, and that then for each new study (or study update), the
necessary forms can be generated automatically. This means a enormous amount of savings, both in time and money.
- XForms send their information to the server in XML format.
This means it is much more easier for the
server to decode the information, and to store the information (mostly this is done in XML format).
- XForms instance data can be saved on the device.
In e.g. an hospital environment (or in case of a patient diary), one cannot expect that the device is continously connected to the server when the form is filled.
In the case of XForms, the instance data (i.e. the data that were filled) can be stored on the device, and retrieved at all times.
This means also that e.g. an investigator can store the incompleted form data on the device, and then later continue to fill the form.
In case no wireless connection is available, all stored XForms can be send to the server when the investigator connects his device to his personal computer (e.g. PDA on cradle).
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