jvanzyl 00/10/19 09:53:26
Modified: xdocs vtl-reference-guide.xml
Log:
- update VTL Ref with quiet reference notation.
Revision Changes Path
1.4 +40 -0 jakarta-velocity/xdocs/vtl-reference-guide.xml
Index: vtl-reference-guide.xml
===================================================================
RCS file: /home/cvs/jakarta-velocity/xdocs/vtl-reference-guide.xml,v
retrieving revision 1.3
retrieving revision 1.4
diff -u -r1.3 -r1.4
--- vtl-reference-guide.xml 2000/10/19 16:23:03 1.3
+++ vtl-reference-guide.xml 2000/10/19 16:53:26 1.4
@@ -166,12 +166,52 @@
to text in your templates.
</p>
+<p>
+ <strong>Quiet Reference Notation</strong>
+ <br/>
+ Velocity's normal behavior upon encountering a
+ reference that is undefined is to output the image
+ of the reference. For example, say you have have
+ the following VTL as part of an HTML for you
+ want to produce:
+</p>
+<p>
+ <source><![CDATA[
+ <input type="text" name="email" value="$email"/>
+ ]]></source>
+</p>
+
+<p>
+ Now when the form initially loads the variable
+ reference $email has no value, but you don't
+ want the text field to have a value of "$email"
+ it should be blank. To circumvent Velocity's
+ normal behavior you use the quiet reference
+ notation: so instead of using $email in the
+ VTL you would use $!email. So the above example
+ would look like the following:
+</p>
+
+<p>
+ <source><![CDATA[
+ <input type="text" name="email" value="$!email"/>
+ ]]></source>
+</p>
+
+<p>
+ Now when the form is initially loaded, while
+ $email has no value yet, an empty string will
+ be output instead of "$email".
+</p>
+
</s1>
<s1 title="Directives">
</s1>
+<s1 title="Macros">
+</s1>
</body>
</document>
