typeHeaders

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ConvertFromOldNGs
Posts: 5321
Joined: Wed Aug 05, 2009 5:19 pm

typeHeaders

Postby ConvertFromOldNGs » Fri Aug 07, 2009 1:21 pm

by Rudy >> Sat, 2 Aug 2008 11:51:06 GMT

Hallo jade programmer

Somebody can help me to explain the codes typeHeaders
a. highestSubId = 1,
b. highestOrdinal = 17,
c. number = 2080;

thanks for your info

Rudy

ConvertFromOldNGs
Posts: 5321
Joined: Wed Aug 05, 2009 5:19 pm

Re: typeHeaders

Postby ConvertFromOldNGs » Fri Aug 07, 2009 1:21 pm

by Dean Cooper >> Sat, 2 Aug 2008 17:49:30 GMT

If you look further down the scm file to the attributeDefinitions and referenceDefinitions sections, you'll see that all properties have an ordinal number, and that sub-object properties (exclusive collections, SLOBs and BLOBs) have a subId number. The "highestSubId" and "highestOrdinal" values in the typeHeaders section are just the highest values of these across all of the properties on the class.

The "number" in the typeHeaders section is the class number. If you click on a class in the IDE, you'll see this number displayed in the first line of the details panel in the browser window.

If you are generating your own scm files, you can leave these values out. They will be allocated by the compiler when the scm file is loaded.

Dean.

ConvertFromOldNGs
Posts: 5321
Joined: Wed Aug 05, 2009 5:19 pm

Re: typeHeaders

Postby ConvertFromOldNGs » Fri Aug 07, 2009 1:21 pm

by Rudy >> Wed, 6 Aug 2008 18:48:39 GMT

Dear Dean

Thanks for your answer
but I want to know further the meaning of these number
( especially highestSubId and highestOrdinal )

is there related to the hierarchy of this Objects ?

Dean wrote :
"They will be allocated by the compiler when the scm file is loaded."
can I direct edit to the code in scm file ?

thanks
Rudy

ConvertFromOldNGs
Posts: 5321
Joined: Wed Aug 05, 2009 5:19 pm

Re: typeHeaders

Postby ConvertFromOldNGs » Fri Aug 07, 2009 1:21 pm

by Dean Cooper >> Wed, 6 Aug 2008 23:50:49 GMT

Whenever you add an exclusive collection, SLOB (string of maximum/unbounded length or greater than 540 characters) or BLOB (ditto string but for binaries) property to a class, it is automatically allocated a unique sub ID by JADE. The sub ID is used to generate object IDs (OIDs) for these properties, because their values are stored as separate objects outside of the parent object. Sub IDs must be unique within a class, but different classes in the same branch can have the same sub IDs (ie: the first exclusive collection, SLOB or BLOB added to any class will have a sub ID of 1).

Every property added to a class is assigned a unique ordinal number. Again, these must be unique within a single class, but different classes (even in the same class branch) will have the same ordinal numbers. Among other things, the ordinal numbers are used by JADE to access properties in your objects.

Yes, you can edit scm files directly in any text editor. So long as any changes that you make are valid, you will be able to load edited scm files into JADE. If you make invalid changes to an scm file, you will get compiler errors when you load it.

Dean.


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