You can't save your
Visualforce pages and components unless they correctly compile. Here's a list
of things to watch out for when creating
Visualforce pages:
- Verify that your component tags start with the correct namespace
identifier like apex:—that
is, apex followed by a colon.
- Make sure that every opening quote and bracket has a closing one.
- Verify that the controller or controller extension is named correctly.
-
Visualforce pages and components created using Salesforce API version
19.0 or higher must be written as well-formed XML. In general, this
means that elements must be correctly nested, non-empty elements must
have an end tag, empty elements must be terminated with a closing
slash (“/”), and
so on. The World Wide Web Consortium (W3C) provides an article on the specifications of well-formed
XML.
The following exceptions are allowed:
- Code that violates well-formed XML is permitted inside JavaScript.
For example, you don't need to use <![CDATA[]]> tags in Visualforce.
- Code that violates well-formed XML is permitted inside expressions.
For example, you don't need to escape quotation marks inside formulas.
- XML directives that are normally required at the beginning of
a page—such as <?xml version="1.0"
encoding="UTF-8"?>—can occur inside top-level container
tags, like <apex:page> and <apex:component>.