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Message
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| gisly |
 Posted: Wed Mar 25, 2015 12:19 am Post subject: Retaining the original value of an escaped XML string |
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Apprentice
Joined: 10 May 2012
Posts: 29
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Hi!
I've got aproblem with Message Broker v. 7
I obtain a response from an HTTP-node. The XML in the response has a tag, which contains an escaped XML string.
It looks like that
| Code: |
<response>
<someTag>SOME TEXT CONTENT WITH XML ENTITIES LIKE &</someTag>
</response> |
Then I have to transform this "inner" XML into an XML tree in a different message flow.
This is how I do it:
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DECLARE responseAsBlob BLOB CAST(the_reference_to_the_response_tag AS BLOB CCSID InputRoot.Properties.CodedCharSetId);
CREATE LASTCHILD OF Environment.Variables.ServiceResult DOMAIN('XMLNSC') PARSE(boBLOB CCSID InputRoot.Properties.CodedCharSetId);
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However, WMB does not preserve the original content of the string. Instead of that, it "unescapes" it all.
As a result, the CREATE LASTCHILD ... PARSE statement works with a string which looks like that
| Code: |
| <someTag>SOME TEXT CONTENT WITH XML ENTITIES LIKE &</someTag> |
Therefore, the string is no longer a correct XML because it has dangling "&".
My question is:
is there any way either to prevent WMB from unescaping these characters
or to make it escape them again when parsing?
The only solution I know now is to simply replace these ampersands manually. But I don't really like it. |
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| fjb_saper |
| Posted: Wed Mar 25, 2015 4:20 am Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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This is working as designed. It looks like the problem is with your original input. see the end of the content:
| Code: |
| ... WITH XML ENTITIES LIKE &</someTag> |
Which translates as expected into:
| Code: |
| ... WITH XML ENTITIES LIKE &</someTag> |
Now if the dangling & is not right, that's the fault of your input. Tell them to fix it!. 
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MQ & Broker admin |
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| gisly |
| Posted: Wed Mar 25, 2015 4:37 am Post subject: |
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Apprentice
Joined: 10 May 2012
Posts: 29
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Hi!
But this
| Code: |
<response>
<someTag>SOME TEXT CONTENT WITH XML ENTITIES LIKE &</someTag>
</response> |
is a valid XML, isn't it?
If it were simply
| Code: |
| <someTag>SOME TEXT CONTENT WITH XML ENTITIES LIKE &</someTag> |
, it would generate a correct XML. So the problem is that WMB is too clever  and unescapes the inner entities |
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| fjb_saper |
| Posted: Wed Mar 25, 2015 4:46 am Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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Now I get your meaning... However how to know which XML to escape and which not to?
I believe your original input should look like
| Code: |
<response>
<someTag>SOME TEXT CONTENT WITH XML ENTITIES LIKE &amp;</someTag>
</response> |
and that this text would then be correctly restored with an escaped ampersand at the end... In other words your dangling & needs to be double escaped...
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| joebuckeye |
| Posted: Wed Mar 25, 2015 4:56 am Post subject: |
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Partisan
Joined: 24 Aug 2007
Posts: 365
Location: Columbus, OH
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I would say any good XML parser would create the final string you are seeing.
How is any parser supposed to know you want it to translate < into < but keep the & as & ? |
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| fjb_saper |
| Posted: Wed Mar 25, 2015 5:10 am Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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| joebuckeye wrote: |
I would say any good XML parser would create the final string you are seeing.
How is any parser supposed to know you want it to translate < into < but keep the & as & ? |
So you're telling me that the output of escaping
is not going to be
| Code: |
| &amp;</tag> |
??
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| kimbert |
| Posted: Wed Mar 25, 2015 5:47 am Post subject: |
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Jedi Council
Joined: 29 Jul 2003
Posts: 5542
Location: Southampton
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fjb_saper's first reply is 100% correct.
gisly: Your reply to fjb_saper is missing the point. Yes, this:
| Code: |
<response>
<someTag>SOME TEXT CONTENT WITH XML ENTITIES LIKE &</someTag>
</response> |
is valid XML.
But this 'XML' document is not valid:
| Code: |
| </someTag>SOME TEXT CONTENT WITH XML ENTITIES LIKE &</someTag> |
I think somebody has tried to construct a test for handling of & but they have forgotten to escape the & in the original XML. Which is exactly what fjb_saper said.
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Before you criticize someone, walk a mile in their shoes. That way you're a mile away, and you have their shoes too. |
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| joebuckeye |
| Posted: Wed Mar 25, 2015 6:05 am Post subject: |
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Partisan
Joined: 24 Aug 2007
Posts: 365
Location: Columbus, OH
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| fjb_saper wrote: |
| joebuckeye wrote: |
I would say any good XML parser would create the final string you are seeing.
How is any parser supposed to know you want it to translate < into < but keep the & as & ? |
So you're telling me that the output of escaping
is not going to be
| Code: |
| &amp;</tag> |
?? |
Sorry, I was saying that if you hand the string:
| Code: |
<response>
<someTag>SOME TEXT CONTENT WITH XML ENTITIES LIKE &</someTag>
</response> |
to an XML parser you will get what he got. My reply was to him, not you (which was not clear in my response as you replied after I opened the thread).
So I agree that the problem was on the input side in creating the "XML string" the OP received and that a proper parser should have created the string you mention with '&amp;'. |
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| gisly |
| Posted: Wed Mar 25, 2015 6:26 am Post subject: |
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Apprentice
Joined: 10 May 2012
Posts: 29
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Thanks.
Well, my problem is that what they are sending has to be a correct XML. And that's all they are obliged to do. I see your point, but I don't think they're obliged to escape the ampersand "two times".
So, the only way to handle it is to replace it within the flow. |
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| kimbert |
| Posted: Wed Mar 25, 2015 7:48 am Post subject: |
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Jedi Council
Joined: 29 Jul 2003
Posts: 5542
Location: Southampton
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| Quote: |
| what they are sending has to be a correct XML |
I agree. But that's a statement of the obvious.
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| And that's all they are obliged to do. |
Not true. They are also obliged to ensure that the content of the 'response' tag is a valid XML document.
But the sender is trying to embed '<someTag>SOME TEXT CONTENT WITH XML ENTITIES LIKE &</someTag>'. That is not valid XML ( try it in your browser). Which is why your message flow has a problem when it tries to parse it.
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| I see your point... |
Kind of you to say so, but I don't think you do....yet.
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| I don't think they're obliged to escape the ampersand "two times". |
I do. They are obliged to escape it first in XML document 2, and then they are obliged to escape the leading '&' on the '&' when it gets embedded in XML document 1.
Your turn
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Before you criticize someone, walk a mile in their shoes. That way you're a mile away, and you have their shoes too. |
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| gisly |
| Posted: Mon Jul 06, 2015 7:20 am Post subject: |
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Apprentice
Joined: 10 May 2012
Posts: 29
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Hi!
Sorry for writing only now, we finally realized kimbert was right.
So we managed to persuade them to send us correct data. |
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