How to output ${expression} in Freemarker without it being interpreted? - el

Question

I'm trying to use Freemarker in conjunction with jQuery Templates.
Both frameworks use dollar sign/curly brackets to identify expressions for substitution (or as they're called in freemarker, "interpolations") , e.g. ${person.name} .
So when I define a jQuery Template with expressions in that syntax, Freemarker tries to interpret them (and fails).
I've tried various combinations of escaping the ${ sequence to pass it through Freemarker to no avail - \${, \$\{, $\{, etc.
Inserting a freemarker comment in between the dollar and the curly (e.g. $<#-- -->{expression}) DOES work - but I'm looking for a more concise and elegant solution.
Is there a simpler way to get a Freemarker template to output the character sequence ${?

Answer 1

This should print ${person.name}:
${r"${person.name}"}
From the freemarker docs
A special kind of string literals is the raw string literals. In raw string literals, backslash and ${ have no special meaning, they are considered as plain characters. To indicate that a string literal is a raw string literal, you have to put an r directly before the opening quotation mark or apostrophe-quote

Answer 2

For longer sections without FreeMarker markup, use <#noparse>...</#noparse>.
Starting with FreeMarker 2.3.28, configure FreeMarker to use square bracket syntax ([=exp]) instead of brace syntax (${exp}) by setting the interpolation_syntax configuration option to square_bracket.
Note that unlike the tag syntax, the interpolation syntax cannot be specified inside the template. Changing the interpolation syntax requires calling the Java API:
Configuration cfg;
// ...
cfg.setInterpolationSyntax(SQUARE_BRACKET_INTERPOLATION_SYNTAX);
Then FreeMarker will consider ${exp} to be static text.
Do not confuse interpolation syntax with tag syntax, which also can have square_bracket value, but is independent of the interpolation syntax.
When using FreeMarker-based file PreProcessor (FMPP), either configure the setting via config.fmpp or on the command-line, such as:
fmpp --verbose --interpolation-syntax squareBracket ...
This will call the appropriate Java API prior to processing the file.
See also:
https://freemarker.apache.org/docs/dgui_misc_alternativesyntax.html
http://fmpp.sourceforge.net/settings.html#templateSyntax

Answer 3

Another option is to use #include with parse=false option. That is, put your jQuery Templates into the separate include page and use parse=false so that freemarker doesn't try and parse it.
This would be a good option when the templates are larger and contain double quotes.

Answer 4

I had to spent some time to figure out the following scenarios to escape ${expression} -
In Freemarker assignment:
<#assign var = r"${expression}">
In html attribute:
Some link
In Freemarker concatenation:
<#assign x = "something&"+r"${expression}"/>

Answer 5

If ${ is your only problem, then you could use the alternate syntax in the jQuery Templates plugin like this: {{= person.name}}
Maybe a little cleaner than escaping it.

Answer 6

Did you try $$?
I found from the Freemarker manual that ${r"${person.name}"} will print out ${person.name} without attempting to render it.
Perhaps you should also take a look at Freemarker escaping freemarker

Answer 7

I can confirm that the
${r"${item.id}"}
is the correct way as an example.
So I kinda full example will look like
<span> Remove </span>
and the output will be :
<span> Remove </span>

Answer 8

In the case when you want to use non-raw strings so that you can escape double quotes, apostrophes, etc, you can do the following:
Imagine that you want to use the string ${Hello}-"My friend's friend" inside of a string. You cannot do that with raw strings. What I have used that works is:
${"\x0024{Hello}-\"My friend's friend\""}
I have not escaped the apostrophe since I used double quotes.