How to add empty paragraph component check in vm file

[Former Member]

Hi Experts,

If there is no content defined in paragraph component then it is displaying ${ctx.content} in email. Can anyone please help me on how to avoid this in email if there is empty component.

Regards, .

[andyfletcher]

There seems to be some confusion around the quiet reference operator.

Try this Groovy from the hAC to see how the ! works with a variety of null and non null data

 import org.apache.velocity.*
 import org.apache.velocity.app.*
   
 ctx = new VelocityContext()

 ctx.put('rhubarb', 'custard')
 ctx.put('foo', null)
 ctx.put('map', [one: '1', two: '2', empty: null])

 tmpl = '''\
 "$rhubarb"
 "$!rhubarb"
 "$foo"
 "$!foo"
 "${map.one}"
 "$!{map.one}"
 "${map.empty}"
 "$!{map.empty}"
 '''

 Velocity.evaluate(ctx, out, 'test', tmpl)
 println ''

You should see

 "custard"
 "custard"
 "$foo"
 ""
 "1"
 "1"
 "${map.empty}"
 ""

[arvind-kumar_avinash]

Thanks, for clarifying my doubt. I understood the concept from the output that you have mentioned.

Just FYI: when I tried executing the code in hAC (v1808), I got some error which I have put in the attached file. If you already know the resolution, please mention that; otherwise, I will look into it later and try to make it work in hAC. link text

[andyfletcher]

I guess it depends on which version of Velocity is being used and therefore which version of Hybris. I ran it on a 6.1 install. Let me try on 1808 and feed back.

[andyfletcher]

On 6.1 Groovy seemed to automatically wrap the out PrintStream in a PrintWriter.

This doesn't appear to be happening, and even Velocity.evaluate(ctx, new PrintWriter(out), 'test', tmpl) doesn't work

Just change the last 2 lines to this:

 writer = new StringWriter()
 Velocity.evaluate(ctx, writer, 'test', tmpl)
 writer.toString()

It writes to an intermediate StringWriter and then just returns that (on the Results tab rather than Output)

[arvind-kumar_avinash]

Thank you very much. It worked.

[Former Member]

 #if( $!ctx.content != "" ))
  ${ctx.content}
 #end
 
 

[arvind-kumar_avinash]

You have mistyped and put an extra ! and an extra ) in your condition. Probably, you wanted to type #if( $ctx.content != "" )

[andyfletcher]

I'm not entirely clear how this is useful. If $ctx.content is blank then surely it doesn't matter if you render it? In fact what you've done is added 2 extra carriage returns and some whitespace to the output. This probably isn't an issue if you're rendering to html but may be if your template is building some other format.

[andyfletcher]

Probably is intended. See the linked documentation from my answer about quiet references. (Although the extra bracket is wrong)

[arvind-kumar_avinash]

If that is the case, I would write it like

  #if( $!{ctx.content} != "" )
   ${ctx.content}
  #end

I thought, probably he meant

  #if( $ctx.content != "" )
   ${ctx.content}
  #end

But I will verify both of them and post my finding if both of them produce the same result or different results.

[andyfletcher]

Mark them as 'quiet references'

https://velocity.apache.org/engine/1.5/user-guide.html#quietreferencenotation

e.g.

 $!{ctx.content}

[Former Member]

its not working