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Escaping DWT ${ } Syntax

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A while back, I was writing about the Dreamweaver Double Lookup technique for Tridion templating.

I was however struggling with escaping the DWT notation, notably with JSTL Expression Language syntax. The EL syntax is the same with DWT's for outputting variables and expressions: ${ expression }

I used to output EL expressions as $[ expression ] and then have a TBB to replace the square brackets with curly braces.

Finally, I found out today not one, but two ways to escape the DWT syntax ${}. Both following expressions output ${'Hello, world'}
  • ${'$'}{'Hello, world'}
  • @@'$'@@{'Hello, world'}
The trick in both cases is to escape the output of the dollar symbol ($) by using it as String parameter in the surrounding @@ @@ or ${ }. What follows is the normal unescaped {'Hello, world'} output.

Now you know... :)

But, wait... we are not there yet! This approach above, only works from a Dynamic CT or a Page Template. The embedded CT will not work as expected. The reason is the two DWT TBBs that get executed with embedded CPs: one for the CT itself and the second for the PT that outputs the Component Presentation.

An embedded CT that contains the code ${'$'}{'Hello, world'} produces DWT output ${'Hello, world'} and when the PT executes, it generates the final output  Hello, world

So the solution is to encode the string twice (you're heading now for a headache) :)

The embedded CT DWT: ${'$'}{'${'$'}'}{'Hello, world'} - I'll explain below
The CT output (i.e. input for PT): ${'$'}{'Hello, world'} - expression explained above
The PT output: ${'Hello, world'} - the desired JSTL EL output

A similar notation for the CT is: @@'$'@@{'@@'$'@@'}{'Hello, world'}

The way this works:
  • ${'$'} or @@'$'@@ outputs a dollar sign ($);
  • {' outputs normally a open curly brace and an apostrophe;
  • ${'$'} or @@'$'@@ outputs a dollar sign ($) again;
  • '} outputs normally an apostrophe and a close curly brace;
  • {'Hello, world'} outputs normally as-is;


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