HTML content in WYSIWYG View

HTML Content in WYSIWYG View

There are many occasions where it is possible to insert HTML content directly into a form page; these include texts, HTML++, HTML Control, Text Control. In some circumstances, this HTML content can cause problems displaying the WYSIWYG View. The issues are as follows:

XHTML vs. HTML

To create the WYSIWYG View, the system renders the page as XHTML, and this standard is more demanding than HTML. For example the following are valid in HTML but invalid in XHTML:

Unclosed tags such as <br> or <p>
Attributes not enclosed in quotes e.g. <font color=red> or <style type=text/css>

When displaying the WYSIWYG View, the system checks whether any added HTML content is valid. If the content is considered to be invalid, the HTML tags will be escaped and displayed as text in the WYSIWYG panel. Note that this problem will not occur at runtime when the form is rendered to a browser using HTML as opposed to XHTML.

Misplaced tags

Both HTML and XHTML have rules controlling which tags are permitted inside other tags. For example the following are invalid:

An <html> tag anywhere inside the <head> tag or <body> tag
A <body> tag inside a <head> tag or vice versa

Browsers typically ignore these errors, but the WYSIWYG View is less forgiving and these problems can cause a number of issues displying the page.

Unclosed Start Tags

An unclosed start tag can cause the entire WYSIWYG View not to display correctly e.g. <font (where the end tag > is missing). In general, browsers are more forgiving than the WYSIWYG View, and invalid content is typically ignored.