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Message
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| chris boehnke |
 Posted: Thu May 28, 2015 11:20 am Post subject: check for existence of an element |
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Partisan
Joined: 25 Jul 2006
Posts: 369
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Hi All,
How do we check for existence of XML tag in a incoming XML element.
Below is the sample xml. I want to check if "Test2" tag exists or not.
<Test1>
<Test2>
<value>556</value>
<description>hfsdkh</description>
</Test2>
</Test1> |
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| Vitor |
| Posted: Thu May 28, 2015 11:22 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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Do you mean you want to test to see if you have:
| Code: |
<Test1>
<Test2>
<value>556</value>
<description>hfsdkh</description>
</Test2>
</Test1>
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or this:
| Code: |
<Test1>
<value>556</value>
<description>hfsdkh</description>
</Test1>
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_________________
Honesty is the best policy.
Insanity is the best defence. |
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| chris boehnke |
| Posted: Thu May 28, 2015 11:26 am Post subject: |
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Partisan
Joined: 25 Jul 2006
Posts: 369
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| I want to check if I have "Test2" xml element |
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| Vitor |
| Posted: Thu May 28, 2015 11:31 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| chris boehnke wrote: |
| I want to check if I have "Test2" xml element |
But why?
If you want know if you have it, you can test directly; if you want to know if you have it because you want to access the value & description elements you can access them anonymously.
In XML terms, are you interested in the existence or not of the complex element Test2, or interested in the child elements?
It only matters because it changes the code you need to do it.
_________________
Honesty is the best policy.
Insanity is the best defence. |
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| Vitor |
| Posted: Thu May 28, 2015 11:32 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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Consider:
| Code: |
<Test1>
<Test2>
<value>556</value>
<description>hfsdkh</description>
</Test2>
<Test3>
<value>557</value>
<description>asadsd</description>
</Test3>
</Test1>
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Still interested in the existence of Test2? Or the number of descriptions you have?
_________________
Honesty is the best policy.
Insanity is the best defence. |
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| chris boehnke |
| Posted: Thu May 28, 2015 11:44 am Post subject: |
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Partisan
Joined: 25 Jul 2006
Posts: 369
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| I still need to test the existence of XML element to do the transformation. |
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| Vitor |
| Posted: Thu May 28, 2015 11:55 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| chris boehnke wrote: |
| I still need to test the existence of XML element to do the transformation. |
Then you need something like:
| Code: |
IF InputRoot.XMLNSC.Test1.Test2 IS NOT NULL THEN
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or
| Code: |
MOVE someReference TO InputRoot.XMLNSC.Test1.Test2;
IF LASTMOVE(someReference) THEN
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or
| Code: |
MOVE someReference TO InputRoot.XMLNSC.Test1;
MOVE someReference FIRSTCHILD;
IF FIELDNAME(someReference) = 'Test2' THEN
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or
...
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Honesty is the best policy.
Insanity is the best defence. |
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| fjb_saper |
| Posted: Thu May 28, 2015 12:05 pm Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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And think about the odd case
| Code: |
<test1>
<test2 xsi:nil="true"/>
</test1> |
Have fun 
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| chris boehnke |
| Posted: Fri May 29, 2015 7:58 am Post subject: |
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Partisan
Joined: 25 Jul 2006
Posts: 369
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Thanks Vitor and fjb!!
| Code: |
| IF InputRoot.XMLNSC.Test1.Test2 IS NOT NULL THEN |
Doesnt work as expected. This statement checks for the value of Test2.
I tried the below one and it works.
| Code: |
MOVE someReference TO InputRoot.XMLNSC.Test1.Test2;
IF LASTMOVE(someReference) THEN |
Thanks!! |
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| inMo |
| Posted: Fri May 29, 2015 9:25 am Post subject: |
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Master
Joined: 27 Jun 2009
Posts: 216
Location: NY
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| To be sure, your solution will check for the presence of Test2. If Test2 is present, but empty, your test will still prove true. As long as your intention is to check for the absence of the element Test2 your code is fine. If however your requirement is such that there is no difference between the absence of Test2 and the presence of an empty Test2, you will need to do something different. |
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| mqjeff |
| Posted: Fri May 29, 2015 9:35 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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| I think I have had some success testing for a missing element by testing if the FIELDNAME is null. |
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| rekarm01 |
| Posted: Sat May 30, 2015 1:47 am Post subject: Re: check for existence of an element |
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Grand Master
Joined: 25 Jun 2008
Posts: 1415
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| chris boehnke wrote: |
| How do we check for existence of XML tag in a incoming XML element. |
Aside from some of the suggestions already given, there is also the EXISTS() function:
| Code: |
| IF EXISTS(InputRoot.XMLNSC.Test1.Test2[]) THEN ... |
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