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Message
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| nize |
 Posted: Tue Sep 08, 2009 6:58 am Post subject: How to learn more about message modeling in WMB |
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Voyager
Joined: 02 Sep 2009
Posts: 90
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Do you have any tips on the subject how to learn more about message modeling in WMB? I am looking for info regarding the different entity types in the mxsd file and how they relate to each other as well as best practices modeling messages. For example it would be useful with a UML diagram showing how (local and global) elements, groups, (complex and simple) types and references relates to each other.
Then of course the namespace complexity makes yet another twist on it, but lets leave that out for the moment. |
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| mqjeff |
| Posted: Tue Sep 08, 2009 7:17 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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namespaces add no complexity. They add clarity.
They allow you to know that the Person element in this namespace is not the same as the Person element in that namespace, and that one has a CityStateZip child, and one has separate children for City, State, and Zip. |
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| nize |
| Posted: Tue Sep 08, 2009 10:31 am Post subject: |
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Voyager
Joined: 02 Sep 2009
Posts: 90
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mqjeff, you are right, namespaces are important, and in my opinion more or less easy to understand when it comes to logical structure, but when addressing them and keeping them in mind in practice (with denotations such as ':' and using/declaring prefixes) I believe they can complicate things. Still - you are right - their functionality is great. 
However, what I wanted to raise with this topic was where to find/understand the rules when modeling messages. I am looking for a better understanding of the concepts or at least sources where I can build such.
Let me take some example questions (I believe I could go on and on):
a. Must a message* be created from a complex type, i.e. contain the attribute 'type'?
b. Which relations are allowed between two different complex types? I believe you can not create a structure such as the following?
| Code: |
<xsd:complexType name="t_msg">
<xsd:sequence>
<xsd:element name="submsg1" type="t_submsg">
</xsd:element>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="t_submsg">
<xsd:sequence>
<xsd:element name="blob" type="xsd:hexBinary">
</xsd:element>
<xsd:element name="blob2" type="xsd:hexBinary">
</xsd:element>
</xsd:sequence>
</xsd:complexType>
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*) The definition of a message (i.e. what separates it from any xsd:element) I guess could be that it contains an xsd:annotation with the following element
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<xsd:appinfo source="WMQI_APPINFO">
<MRMessage messageDefinition="..."/>
</xsd:appinfo> |
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| mqjeff |
| Posted: Tue Sep 08, 2009 10:39 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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Do not make any attempt to manipulate the mxsd file outside of the Message Definition Editor.
Why are you trying to do that? |
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| nize |
| Posted: Tue Sep 08, 2009 10:51 am Post subject: |
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Voyager
Joined: 02 Sep 2009
Posts: 90
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| One reason for that could be that you what to use search and replace functions, for example assigning nillable="true" to all elements, but mostly I am referring to the text structure in order to make myself clearer. I believe there is a greater chance to understand each other when comparing code. |
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| mqjeff |
| Posted: Tue Sep 08, 2009 11:26 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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| The structure of the mxsd file is "internal" to the product. |
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| nize |
| Posted: Tue Sep 08, 2009 11:50 am Post subject: |
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Voyager
Joined: 02 Sep 2009
Posts: 90
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Ok, tomorrow I will try to express my example questions again without the use of code. I just tried to be explicit and clear  .
And btw I think that this is an advantage of the WMB environment, that all components can be read in text - takes away the mystery that GUIs sometimes bring. |
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| nize |
| Posted: Wed Sep 09, 2009 1:18 am Post subject: |
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Voyager
Joined: 02 Sep 2009
Posts: 90
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Meanwhile maybe someone else have nice tips on useful resources on message modeling, helping you to learn in a "stringent" way?
| Quote: |
| I am looking for info regarding the different entity types in the mxsd file and how they relate to each other as well as best practices modeling messages. For example it would be useful with a UML diagram showing how (local and global) elements, groups, (complex and simple) types and references relates to each other. |
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| mqjeff |
| Posted: Wed Sep 09, 2009 5:34 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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Here's the thing.
An mxsd is JUST an XSD.
It's the same "model" - an MRM "element" has the same logical meaning as an XSD "element", it's the same syntax, it's the same everything.
It doesn't actually help you a significant amount in USING MRM nor in building models to know that.
There's a lovely tutorial that has been kindly "stickied" in this very forum, that you probably have passed over every time you have come to read these responses.
Oh, and, of course, there's an entire SECTION of the Information Center on Message Broker called "Developing Message Models" that tells you *everything* you want to know, including most of what you've already asked about. |
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| nize |
| Posted: Wed Sep 23, 2009 6:41 am Post subject: |
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Voyager
Joined: 02 Sep 2009
Posts: 90
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Thanks for your suggestions, mqjeff!
I dont think that the information center is very pedagogical when it comes to message models, e.g. explaining usual misunderstanding and giving best practices. That is why I hoped there were better resources.
I have seen a tutorial on this forum, but it was very specific for a specific task, which of course is great when performing that one. What I was searching for is general best practices when it comes to modeling messages.
I have been confused with questions such as when to define a group, a complex type, when to make the objects local/global, how the messages relates to the other objects and so on.
I guess I will think about these things again the next time I need to perform advanced message modeling. |
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| kimbert |
| Posted: Wed Sep 23, 2009 7:18 am Post subject: |
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Jedi Council
Joined: 29 Jul 2003
Posts: 5542
Location: Southampton
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Hi there,
- No reason why your example XSD above should not be represented in a message definition file - it is legal XML schema.
- An MRM message must be based on a global complex element - so the mxsd resulting from the above schema would only be useful as an include/import.
- You can use almost any valid XSD structure in your message definition files. But don't use attributes unless you are modelling actual XML attributes. ( and if you are modelling an XML message, you should be targeting your message set at XMLNSC, not MRM ).
- Whether you use local or global type/elements is up to you - I prefer to use local definitions wherever possible, for the same reason that I make my Java methods/members 'private' wherever possible.
For any other questions, I suggest that you exploit the combined brain power of this forum to crowd-source a solution. Parsing is an inherently complex business. Even if the infocenter was excellent, I suspect that a lot of help would still be required when modelling a complex non-XML message. |
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| nize |
| Posted: Wed Sep 23, 2009 10:32 pm Post subject: |
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Voyager
Joined: 02 Sep 2009
Posts: 90
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Thanks for your comments, kimbert!
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| if you are modelling an XML message, you should be targeting your message set at XMLNSC, not MRM |
If I want to validate a XML message I need to use the MRM parser. Am I not right? Anyway I believe this was the case for WMB5. Maybe it has changed in WMB6.1 so that you can provide the message flow with a XSD and validate your incoming (or outgoing) messages using that one? |
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| kimbert |
| Posted: Wed Sep 23, 2009 11:09 pm Post subject: |
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Jedi Council
Joined: 29 Jul 2003
Posts: 5542
Location: Southampton
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| nize |
| Posted: Thu Sep 24, 2009 12:22 am Post subject: |
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Voyager
Joined: 02 Sep 2009
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