Layer7 API Management

Hi,

I'm creating a policy for sending a string through RAW assertion to the backend server and receiving a response from the server.

The request string is fixed length but the length of response string is unpredictable.

I need to get each value from the response string's different part and transfer it to JSON format.

For example:

Response String = AA9567BS33411002AAGF1FFG

AA9567 = Company ID

BS33411 = Customer ID

002 = The amount of Txn

AAGF = First Txn amount 

1FFG =  Second Txn amount

I'll know the number of Txn from the position 13-15(started from 0) of the string, but I'll never know the number before receiving the string.

I have no idea how to design the policies.

Is there any suggestion or any assertion suit to do this?

Best Regards,

Hi Gary,

Are the positions consistent for the Txn always in the same position in the response? or are the length of the values always consistent? Meaning, is the company ID always 6 characters, the customer ID always 7 characters, etc..

If so you can use the Xpath assertion substring function

https://communities.ca.com/message/242149526-re-substring-function?commentID=242149526&et=watches.email.outcome#comment-… 

The string can be parsed based on any consistent value, i.e: Txn start at position 13-15.

Regards,

Joe

Hi Joe,

Yes. The position and length of every element are fixed.

So the assertion you mentioned is good for this case but they'is still one question.

If I can only know the whole string length after I received this string, that means it may contain few or so many Txn. 

How do I design the XPath assertion for the loop?

Best Regards,

Hi Gary,

Do you mean that there could be multiple Txn values in the string? If that is the case you may be able to nest the Xpath statements inside of the 'Run Assertions for Each Item' assertion. This can iterate through a multivalue context variable.

Run Assertions for Each Item Assertion - CA API Gateway - 9.3 - CA Technologies Documentation 

Regards,

Joe

Hi

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With Kind Regards
Dirk