Htykuut

In velocity i have a problem. Let me explain clearly as below
I have declared in class

private final static int MAX_TOOL_TITLE_LENGTH = 20;



//Putting into context

context.put("maxToolTitleLength","MAX_TOOL_TITLE_LENGTH");

Now in vm file i am setting the context variable value as different

#if(true)

  #set($maxToolTitleLength=99) 

#end

In the above lines in vm file i set value as 99.i do not want to set this value to context variable.i want to limit the scope of the variable with in the if only. After if i don't want to get the value as 99.it remains same value as in the context. Is it possible in velocity in any of other ways?

Thanks in advance.

There is actually a way to introduce local variables in Velocity, though it is a bit surprising:

#foreach ($maxToolTitleLength in [99])

...text that uses this $maxToolTitleLength definition...

#end

## now $maxToolTitleLength is back to whatever value it had before

[99] is a list with one element, 99, so this is a loop that executes one time. Within the loop $maxToolTitleLength has the value 99. You can also #set ($maxToolTitleLength = $anotherValue) within the loop. The value from before the #foreach will be restored after the loop.

The #foreach-hack, as found by @user2624542, works to generate local scopes. However, at least in the quite old Velocity 1.5 of Polarion the behavior inside a macro is different than outside.

Inside macros the scoping works for existing variables (in the global context), but not for undefined ones.

$foo ## undef

#foreach ($foo in [99])

  $foo ## 99

  #set($foo=100)

  $foo ## 100

#end

$foo ## undef



#set($foo=0)

$foo ## 0

#foreach ($foo in [99])

  $foo ## 99

  #set($foo=100)

  $foo ## 100

#end

$foo ## 0

whereas inside a macro

#macro(bar)

  $foo ## undef

  #foreach ($foo in [99])

    $foo ## 99

    #set($foo=100)

    $foo ## 100

  #end

  $foo ## 100 NOT undef

#end



$foo ## undef

#bar()

$foo ## 100 NOT undef



#macro(bar2)

  $foo ## 0

  #foreach ($foo in [99])

    $foo ## 99

    #set($foo=100)

    $foo ## 100

  #end

  $foo ## 0

#end



#set($foo=0)

$foo ## 0

#bar2()

$foo ## 0

It is not possible to change the value of a context object and make this change local only. I don't see why you don't simply use a new variable in your template for this?

#if (true)

  #set($thisTitleLength=99) 

#end

Or if you do need to use the context variable for this, just restore the context variable after you finish the block where you want to change its value:

#if (true)

  #set($maxToolTitleLength=99) 

  ## Do whatever you want with the new value

  ...

  ## Now restore its value

  #set($maxToolTitleLength=20)

#end