Read on. My answer is a bit long.
Em Ter, 2002-03-05 �s 12:49, Ara Abrahamian escreveu: > > Class-level: > > @ejb:persistence table-name="foo" datasrouce="jdbc/FooDS" > > > > method-level: > > @ejb:persistence-field column="bar" > > Looks good. > > Marcus Brito (?) That's me :) > What do you think about @db:mapping instead of ejb:persistence? We can > support JDO too for example. I really prefer this one. I really prefer @ejb:persistence instead of @db:mapping. "persistence" is a more generic word and the one used in the EJB specification. There is no need to use "database". However "table" and "column" are very database-centric terms anyway -- perhaps we should use "schema" and "attribute". But then this may cause some confusion... well, let's see what other people have to say. I also prefer a single "ejb:persistence" tag instead of "ejb:persistence" and "ejb:persistence-field". > The other question is how we're going to start implementing it and from > where. This is a task for people maintaing vendor tasks and templates. They should always look on these tags *in addition* to the vendor-specific tags. For example, in JBoss (which is my playing field) templates, it should look for @ejb:persistence table-name in addition no @jboss:table-name. The template would be something like this: <XDtClass:ifHasClassTag tagName="jboss:table-name"> <table-name><XDtClass:classTagValue tagName="jboss:table-name" paramName="table-name" paramNum="0"/></table-name> </XDtClassifHasClassTag> <XDtClass:ifDoesntHaveClassTag tagName="jboss:table-name"> <XDtClass:ifHasClassTag tagName="ejb:persistence" paramName="table-name"> <table-name><XDtClass:classTagValue tagName="ejb:persistence" paramName="table-name"/></table-name> </XDtClass:ifHasClassTag> </XDtClass:ifDoesntHaveClassTag> Note that using this approach enables the vendor template to use the "new" standard tags while retaining backwards compatibility. The bad news is that as you can see from the above example, the template editing will be a boring task. Another approach is to write a JBossTagHandler with methods like ifHasTableName and getTableName, that would already look for the correct tags. If done this way, the above template would be like this: <XDtJBoss:ifHasTableName> <table-name><XDtJBoss:tableName/></table-name> </XDtJBoss:ifHasTableName> Much nicer, huh? The <XDtJBoss:tableName/> method would look first for the @jboss:table-name tag in the current class and if not found look for @ejb:persistence table-name="" tag. The good news here is that coding the JBossTagHandler class is more fun then editing templates. And far more easier to debug. The bad news is, well, that it would require coding a new class, what is a more radical approach then editing templates. My personal position on what was questioned above: The tags should avoid database-specific terms. The two mentioned examples could be: @ejb:persistence schema="table" @ejb:persistence attribute="column" And about the option between modifying templates and writing new tag handlers, I prefer writing new tag handlers. It's more elegant. -- Ja ne, Marcus Brito mailto: [EMAIL PROTECTED] Anime Gaiden - De f�s para f�s, sempre. http://www.animegaiden.com.br
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