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From James McMahon <jsmcmah...@gmail.com>
Subject Re: Detect whether a flowfile has a particular attribute
Date Thu, 08 Jun 2017 13:54:52 GMT
I do understand now. Thank you very much Mark. -Jim

On Thu, Jun 8, 2017 at 9:34 AM, Mark Payne <markap14@hotmail.com> wrote:

> Jim,
>
> The first expression will return false. None of the expressions below will
> ever throw an Exception.
>
> You could even chain them together like ${myAttribute:toLower():length():gt(4)}
> and if myAttribute does not
> exist, it will return false, rather than throwing an Exception.
>
> Thanks
> -Mark
>
>
> On Jun 8, 2017, at 9:32 AM, James McMahon <jsmcmahon3@gmail.com> wrote:
>
> So then if myAttribute does not even exist in a particular flowFile, the
> first expression will return a null value rather than throw an error. Thank
> you very much Mark. -Jim
>
> On Thu, Jun 8, 2017 at 8:44 AM, Mark Payne <markap14@hotmail.com> wrote:
>
>> Jim,
>>
>> You can use the expression:
>>
>> ${myAttribute:isNull()}
>>
>> Or, alternatively, depending on how you want to setup the route:
>>
>> ${myAttribute:notNull()}
>>
>> If you want to check if the attribute contains 'True' somewhere within
>> its value,
>> then you can use:
>>
>> ${myAttribute:contains('True')}
>>
>> Thanks
>> -Mark
>>
>>
>> > On Jun 8, 2017, at 8:19 AM, James McMahon <jsmcmahon3@gmail.com> wrote:
>> >
>> > Good morning. I receive HTTP POSTs of various types of files. Some have
>> a particular attribute myAttribute, some do not. I want to route the
>> flowfiles to different workflow paths depending on the presence of this
>> attribute. Can I use RouteAttribute and the expression language to do that,
>> something like this:
>> >
>> > hasTheAttributeOfInterest           ${anyAttribute("myAttribute":
>> contains('True')}
>> >
>> > I ask because the expression guide did not say whether a False is
>> returned or the processor throws an error if the attribute does not exist
>> in the flowfile. I may have missed that. I wanted to see if anyone in the
>> group has experience in this regard?
>> >
>> > Thanks in advance for your insights. -Jim
>>
>>
>
>

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