Variable substitution inside Regular Expression.

, ,
1

Hi Gurus,

I am using Branch with Regular expression.

Code :

Two variables in pipeline.
testStr = abc
validStrList = abc|xyz|efg
BRANCH - Evaluate Label = False, Switch on /testStr
SEQUENCE - Label = /%validStrList%/

As you can see I would like to peform variable substitution before evaluation the regular expression. This is not working.

If I hard code values of validStrList in regular expression it works.

Has any one tried this? Or any other suggestions, workarounds??

Appreciate your help.
Ajit

2

When you are doing a variable substitution you need to set the Evaluate Label to True.

3

Ajit,

Try this:
In addition to your to your testStr and validStrList create another var evaluateStr and set its value to the expression that you want to evaluate, ie hardcode %testStr% == /%valStrList%/ into evaluateStr and check mark ‘Perform Variable Substitution’ when hardcoding the value. Now create your branch as follows:

Branch [Evaluate Label = True]
– Sequence [Label = %evaluateString%]
---- Do your stuff here
– Sequence [Label = $default]

Hope this helps

~ Rohit

4

Thanks Rohit and altgecko,

I was very much convinced with Rohit’s solution, but its not working either…

I tried it. I dont think we can put regular expression with variable substitution…

Rohit can you please give it a quick go… It alwas goes in first sequence cause lable %evaluateString% means if evaluateString exist or not null then go in… and it does exist as "abx == /abc|xyz|efg/ " I also tried with value of evaluateString = “/abc|xyz|efg/”, still dont work…

I believe for Regular Expression we have to use evalute label equal to false but then we can not do variable substitution to have regualar expression dynamic…:frowning:

:frowning:

Thanks…

5

My bad! Yes it goes to the first sequence because the var evaluateString exists in the pipeline. Hmmm I tried it many other ways but nothing seems to be working.

I think you’ll need to use other ways of determining whether your input var (testStr) is valid or not - you know, by tokenizing valStrings, looping over tokens and then branching… unless u find a way of doing this. If so please do share it with us.

~ Rohit

6

Thanks Rohit,

I know the tokenizing way to doing it… I am already doing it at some other place but I believe it will be bit expesive than regular expression… But doesnt look like there is any other way…

Thanks for your inputs guys… Atleast its clear now…

Cheers,
Ajit

7

Perhaps I’m not understanding the problem correctly, but I think you can do this using PSUtilities, as long as you’re running at least JVM 1.4. Before you do your BRANCH, call PSUtilities.regex:matches and map testStr to ‘input’ and validStrList to ‘regex’. Then BRANCH on the value of ‘match’ (true or false) to decide which sequence to take. HTH,

Tim

8

Thanks Tim,

PSUtilities.regex:matches service did the job. Apologies for troubles guys. I should have checked PSUtilities before hand…

Ta,
Ajit

9

Variable substitution is not supported for regular expression in branch step. i had to wrote a small java service using java.util.regex.* for building my own rule engine.

Advantage site also listed this problem as unsupported.
[url]https://advantage.webmethods.com/advantage?targChanId=kb_home&oid=1613807838[/url]

Thanks
Ravi

10

I had some similar requirement where I had to substitute a pipeline variable in regex pattern .

I added a map step for substituting the pipeline variable in regex pattern and then passed it to PSUtilities.regex:matches

Capture.PNG
Capture.PNG687×749 19.7 KB