how to change parameter variable value in a recursive macro? - freemarker

Question

I want to show a number sequence in black color, and show nested sequence number in red. Here is my marco code:
<#macro test datas isNested>
<#list datas as d>
<#if d?is_enumerable>
<#local isNested = true>
<#if isNested>
<#-- become red if it is nested -->
Hi, I am going to be red!
<#-- some business code -->
</#if>
<#test d isNested/>
<#else>
<#if isNested>
<span style="color:red;">${d}</span>
<#else>
${d}
</#if>
</#if>
</#list>
</#macro>
call it like this: <#test [1,2,3,[4,5],6,7] false/>
I want it to be: 1 2 3 Hi, I am going to be red! 4 5 6 7
only 4 and 5 show in red.
But now I get this:
1 2 3 Hi, I am going to be red! 4 5 6 7
all of 4 5 6 7 are show in red.
I think this line of code <#local isNested = true> play the trick. I also try to use assign, global, all of 1 2 3 4 5 6 7 are black.
so how should I do?
Thx in advance.
PS:
I don't know how to make code show in red in stackoverflow, if any one knows plz helps me to edit my code.

Answer 1

Your problem is not FreeMarker-specific. You flip the isNested local variable (which also holds the parameter value) to true before the recursive #test call, and you leave if so after the recursive macro call has returned. So when the iteration of 6 and 7 comes, isNested is already true. You should not set the isNested at all, just pass true to the recursive call. Here:
<#macro test datas isNested=false>
<#list datas as d>
<#if d?is_enumerable>
Hi, I am going to be red!
<#test d true />
<#else>
<#if isNested>
<span style="color:red;">${d}</span>
<#else>
${d}
</#if>
</#if>
</#list>
</#macro>
<#test [1,2,3,[4,5],6,7] />