I need to assign an escaped ${expression} to a variable in Freemarker
From the question here, it's clear that we can escape the $ sign in this way
${r"${expression}"}
This works perfectly outside Freemarker context, but doesnot working inside. I am trying to do
<#assign x = "${r"${expression}"}">
But getting the following error:
Template inclusion failed:
You can't use "${" here as you are already in FreeMarker-expression-mode. Thus, instead of ${myExpression}, just write myExpression. (${...} is only needed where otherwise static text is expected, i.e, outside FreeMarker tags and ${...}-s.)
What is the way to achieve this? Thanks in advance.
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"${expression}"/>
Like this:
<#assign x = r"${expression}">
Related
I have an XML document passed as root to a Freemarker template. I want some values from this XML to be assigned to variables as a string and later concatenate/print them out.
<#assign MyVar = root.child1.child2.child3.mynode>
The issue here is that even when a path doesn't exist MyVar gets assigned with a sequence+hash which cannot be printed out or converted to string. This variable although returns false for ?has_content, it needs an extra step for these checks and I have this same issue with many variables and across template files and modules.
The only solution I have been able to find was
<#assign MyVar = root.child1.child2.child3.mynode>
<#assign MyVar = MyVar ?has_content?then(MyVar , "")>
I am looking for something like the Default Value Operator which also checks for nulls like ?has_content.
Does Freemarker provide any simpler one line function to check if a variable has no content and assign it with a default?
In short:
<#assign myVar = root.child1.child2.child3.mynode[0]!''>
Or just <#assign myVar = root.child1.child2.child3.mynode[0]!> if the implicit multi-typed default value doesn't cause problems (like when you just print it with ${}).
Why: XML queries (just like XPath queries) always return a sequence of matching nodes. There are maybe 0 such nodes (or 1, or multiple). An empty sequence is not a "missing value" according the template language. It's an inconvenient mismatch with the XML data-model. But while the sequence always exists, its 1st element ([0]) doesn't, so you can use all the missing value handler operators with it as usual.
I am trying to assign a variable from another variable. My code looks like this
<#macro ctglink c rhs x y z m e b>
<#assign ctg>
<#if ctgroutes["${y}..${x}-${m}"]??>ctgroutes['${y}..${x}-${m}']
<#elseif ctgroutes["${x}..${y}-${m}"]??>ctgroutes['${x}..${y}-${m}']
<#else>{}</#if>
</#assign>
However, this ctg variable is evaluating to just ctgroutes['227..257-TPPMD04X02'] its not actually evaluating the string itself.
I have tried ?eval, and ?interpret and a bunch of other very hacky things to get this to work, no go. Even the {} is a string
Basically, I need the assign function to work like the old PHP eval() function or something. I am trying to access values in a Map whose keys are derived from the state of the data, so I don't see any easy way to query my Map without evaluating keys.
Update:
I forgot to include the elseif in there
Either way, I tried <#assign ctg = ctgroutes["${y}..${x}-${m}"]!ctgroutes["${x}..${y}-${m}"]> but I get the following error:
Caused by: freemarker.core.InvalidReferenceException: The following has evaluated to null or missing:
==> ctgroutes["${y}..${x}-${m}"]!ctgroutes["${x}..${y}-${m}"] [in template "RouteCompare-WptTable.ftlh" at line 5, column 24]
I would like a null result to just return an empty map, however that doesn't seem possible:
Caused by: java.lang.RuntimeException: freemarker.core.InvalidReferenceException: The following has evaluated to null or missing:
==> ctgroutes["${y}..${x}-${m}"]!ctgroutes["${x}..${y}-${m}"] [in template "RouteCompare-WptTable.ftlh" at line 5, column 24]
So basically, my goal is I need to assign a variable that can take 1 of 3 values:
ctgroutes["${y}..${x}-${m}"] // Assuming it is not null
ctgroutes["${x}..${y}-${m}"] // Assuming it is not null
{} // An empty map
What is the best way to do that?
If I understand well what you want to achieve, you can write it like this:
<#assign ctg = ctgroutes["${y}..${x}-${m}"]!ctgroutes["${x}..${y}-${m}"]!{}>
Also note that <#assign target>...</#assign> is for capturing the output printed between the two tags into the target variable (instead of actually printing it). So target will always store a string or markup value. Also things outside FreeMarker tags and ${} are just static text, and won't be parsed. So, the naive but working approach is just using #if/#elseif/#else and have a separate #assign ctg = ... inside each of them, but you can make this much sorter with the ! operator, as it was shown.
I am absolutly new in FreeMarker and I have the following problem working on a Spring MVC application that use this template engine.
So into a controller method I put an int representing the current year (2016) into the model, in this way:
model.addAttribute("annoCorrente", annoCorrente);
Then, into my FreeMarker page I have to assign this value to a variable, so I write the following expression:
<#assign a = ${annoCorrente}>
But in this way I obtain the following error message:
[col. 86] You can't use "${" here as you are already in FreeMarker-expression-mode. Thus, instead of ${myExpression}, just write myExpression. (${...} is only needed where otherwise static text is expected, i.e, outside FreeMarker tags and ${...}-s.)
Why? How can I correctly initizialize a FreeMarker variable with the value obtained from the model associated to this view?
Change <#assign a = ${annoCorrente}> to <#assign a = annoCorrente>
(or you can do <#assign a = "${annoCorrente}"> but this is not recommended)
I would like to assign the result of an interpreted variable to another varialbe.
Freemarker provides the built-in ?interpret to interpret a variable holding an ftl expression. See http://freemarker.sourceforge.net/docs/ref_builtins_expert.html#ref_builtin_interpret
If I do
[#if var1?has_content && var1?starts_with(r"${")]
[#assign interpretedValue = var1?interpret!""]
[#interpretedValue/]
[/#if]
The [#interpretedValue/] will output the interpreted value.
However, I'd like to assign the value of the interpreted value to a variable (in order to do some things such as ?has_content in the rest of my code). I tried [#assign varInterpretedValue = #interpretedValue] but this does not work.
Is this possible?
Yes, like this:
[#assign capturedOutput][#(var1!'')?interpret /][/#assign]
${capturedOutput} [#-- Attention! Put this into #noescape if you are inside #escape! --]
Note that the !'' suff has to before the ?interpret, otherwise it doesn't do anything (since the result of ?interpret is always non-null).
I am trying to create a FreeMarker macro that can return the interpolation of a concatenation of a string and the input variable:
<#macro findValue var>
<#if (.vars["foo." + var]) ??>
.vars["foo." + var]
<#else>
${.vars["bar." + var]}
</#if>
</#macro>
Unfortunately it doesn't work. Firstly, ${.vars["bar." + var]} gives an undefined error. Secondly, the if condition always returns false even when I can see that the sub variable do exist. It seems like the .vars variable can only look up root variables, but not sub variables like foo.test.
In FreeMarker, foo.bar is the same as foo["bar"], but inside the [] you can have an arbitrary expression that evaluates to a string. So the expression you are looking for is simply foo[var].
BTW, what your macro tries to do is just ${foo[var]!bar[var]}