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Message
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| yaemu |
 Posted: Tue Mar 29, 2011 4:57 am Post subject: Convert a Character to Reference issue |
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Novice
Joined: 27 Oct 2010
Posts: 17
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Hi,
I have a UDP variable and its data type is CHARACTER,
the value of the UDP will be a path of an element in the message tree, for example:
'InputRoot.XMLNSC.MSG.Body.elem'
I need to assign this value to variable of a reference data type,
because I need to access message element
the Cast function does not convert to a reference Data type.
Do you have any idea how to convert it?
Thanks, |
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| lancelotlinc |
| Posted: Tue Mar 29, 2011 5:23 am Post subject: |
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Jedi Knight
Joined: 22 Mar 2010
Posts: 4941
Location: Bloomington, IL USA
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| Quote: |
| A field reference consists of a correlation name followed by zero or more path elements separated by periods. |
This is why cast would not work.
Why not try hard coding an example within the Compute node. When you figure out the combination that works, transfer that info to the UDP. You may need to use two UDPs.
I'm not an "ex-pert" on ESQL, just a "pert". mqjeff or vitor may know some other things that could help here.
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Save $20: Coupon Code: MQSERIES_READER |
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| paintpot |
| Posted: Tue Mar 29, 2011 6:34 am Post subject: |
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Centurion
Joined: 19 Sep 2005
Posts: 112
Location: UK
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If I understand your question, it is how to access part of the message tree based on a variable, which you have as a UDP.
Use curly braces.
| Code: |
SET OutputRoot.XMLNSC.{UDP_testvar}.restOfTree = "blah";
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etc  |
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| mqjeff |
| Posted: Tue Mar 29, 2011 7:54 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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Curly braces only evaluate a single level. So OutputRoot.XMLNSC.Body.{fieldName} will work if fieldName = 'UserValue' but not if it = "user.value".
You can use EVAL. |
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| paintpot |
| Posted: Tue Mar 29, 2011 8:23 am Post subject: |
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Centurion
Joined: 19 Sep 2005
Posts: 112
Location: UK
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I want to be mqjeff when I grow up  |
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| gechu |
| Posted: Sun May 22, 2011 11:12 pm Post subject: |
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Apprentice
Joined: 27 Feb 2008
Posts: 48
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Hi, I´m not very comfortable with EVAL yet, can you give me a hint about how to use it when creating a reference where the trailing field identifier contains dots. Here is my example. I´ve added "" around the string with dots:
| Code: |
| DECLARE myRef REFERENCE TO InputLocalEnvironment.Variables.config.{messageRef.msgType}.{messageRef.distributorId}.{messageRef.recordType}."Destination.FTP.user"; |
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| kimbert |
| Posted: Mon May 23, 2011 12:52 am Post subject: |
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Jedi Council
Joined: 29 Jul 2003
Posts: 5542
Location: Southampton
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EVAL uses a lot of CPU. You could achieve the same result by splitting up the string using POSITION and SUBSTRING. Loop until POSITION('.' IN trailingFieldIdentifier REPEAT N) returns zero. Each time around the loop, increment N and MOVE myREF FIRSTCHILD Name thisFieldName.
...and don't forget to check LASTMOVE after every MOVE. |
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| gechu |
| Posted: Mon May 23, 2011 2:54 am Post subject: |
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Apprentice
Joined: 27 Feb 2008
Posts: 48
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Thanks Kimbert for the reply. Haven´t tried it in code yet, but I get the basic idea.
You wrote that EVAL used a lot of CPU. I was planning to use EVAL to dynamically call a function like this myGenericFunction(anyParam1, anyParam2, dynamicFunction);
in dynamicFunction I would store in a string the name of the function that I wanted to call.
Should I avoid using EVAL or are there better ways to handle dynamic function calling? |
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| kimbert |
| Posted: Mon May 23, 2011 3:32 am Post subject: |
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Jedi Council
Joined: 29 Jul 2003
Posts: 5542
Location: Southampton
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| Quote: |
| Should I avoid using EVAL |
No, not necessarily. It depends on whether your message flow needs to keep its CPU usage to a minimum. Sometimes a solution that uses EVAL is the simplest and best.
MGK may have some detail to add to this... |
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| mqjeff |
| Posted: Mon May 23, 2011 4:55 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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With eval, you would have something like
| Code: |
| DECLARE myRef REFERENCE TO EVAL('InputLocalEnvironment.Variables.config.'||messageRef.msgType||'.'||messageRef.distributorId||'.'||messageRef.recordType||'.'||Destination.FTP.user); |
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| gechu |
| Posted: Mon May 23, 2011 6:01 am Post subject: |
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Apprentice
Joined: 27 Feb 2008
Posts: 48
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| Thanks a lot! |
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| gechu |
| Posted: Tue May 24, 2011 10:54 pm Post subject: |
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Apprentice
Joined: 27 Feb 2008
Posts: 48
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Just when I thought I was out they [read ESQL] dragged me back in!!
My problem description wasn´t accurat because I didn´t understand the actual problem.
Here it is, I think, in plain text what I want to do. But it doesn't work:
| Code: |
DECLARE TargetRef REFERENCE TO InputLocalEnvironment.Variables.config;
DECLARE TargetStr CHARACTER messageRef.oneID || '.' || messageRef.anotherID || '.' || 'Destination.FTP.userName';
-- resolves to string: myID.anotherID.Destination.FTP.userName,, a field with exacly that name exists as a child to where TargetRef points.
-- try to move my reference to the desired field:
MOVE Vidb_TargetRef FIRSTCHILD NAME Vidb_TargetStr; |
What am I doing wrong? |
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| gechu |
| Posted: Wed May 25, 2011 1:08 am Post subject: |
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Apprentice
Joined: 27 Feb 2008
Posts: 48
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strangely, if I hardcode the string like this
| Code: |
| MOVE Vidb_TargetRef FIRSTCHILD NAME 'myID.anotherID.Destination.FTP.userName' |
it works.. |
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| gechu |
| Posted: Wed May 25, 2011 2:03 am Post subject: |
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Apprentice
Joined: 27 Feb 2008
Posts: 48
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| stupid typo. Problem solved. |
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