#: Christophe Lombart changed the world a bit at a time by saying (astral date:
1/16/2006 9:48 PM) :#
On 1/16/06, Alexandru Popescu <[EMAIL PROTECTED]> wrote:
#: Christophe Lombart changed the world a bit at a time by saying (astral date:
1/16/2006 5:25 PM) :#
> Concerning issue http://issues.apache.org/jira/browse/GRFT-54,
> Why do you think about the following mapping :
>
> <class-descriptor className="xxx.File" jcrNodeType="nt:file" >
> <field-descriptor fieldName="path" path="true" />
> <subnode-descriptor jcrName="jcr:content" ... >
> <field-descriptor fieldName="mimeType" jcrName="jcr:mimeType" ...
/>
> <field-descriptor fieldName="encoding"
> jcrName="jcr:encodiging" .../>
> <field-descriptor fieldName="data" jcrName="jcr:data" ... />
> ....
> </subnode-descriptor>
> </class-desciptor>
>
> the "subnode-descriptor" is there to create a new subnode called
> "jcr-content" which will contains some object attributes like
> mimeType, encoding, ...
>
> Anyway, I like the "converter" idea. At least, it quite easy to
> implement it for the fd.
> Converters for cd already exists but they need to be review. But now,
> we have to think about how to use the converters for the bd.
>
> (I don't speak now on inheritance, we can start this discussion later).
>
The proposal you are making is quite nice for this particular example. But I
cannot say how
extensible it is (by looking at it I would say that it is pretty much the
bean-descriptor). I would
like that before introducing more descriptors to be sure that a new one will be
able to fill in a
whole range of solutions and not just a particular one. The same applies to the
existing ones.
ok - can we create a new jira issues which will contain all use cases.
It is quite difficult to remember all possibilities.
Thanks
Not sure what you are asking :-(. Is your question about creating a JIRA issue for each of the
suggested improvements? If yes, than I would say that I would prefere having it in the ML than
directly on JIRA, and upon concluding adding a JIRA with only the conclusion. But if you think JIRA
is better to handle this discussion than go ahead and open the necessary enhancement requests.
cheers,
./alex
--
.w( the_mindstorm )p.
./alex
--
.w( the_mindstorm )p.
>
> On 1/14/06, Alexandru Popescu <[EMAIL PROTECTED]> wrote:
>> #: Christophe Lombart changed the world a bit at a time by saying (astral
date: 1/13/2006 11:20 AM) :#
>> > On 1/13/06, Alexandru Popescu <[EMAIL PROTECTED]> wrote:
>> >
>> >> considering the GRFT54 example, you will write:
>> >>
>> >> <bean-descriptor fieldName="file"
>> >> converterClass="NtFileConverter" />
>> >>
>> >> and NtFileConverter will be responsible for creating the nt:file node
structure. Same mechanism will
>> >> work for fetching.
>> >>
>> >
>> > I like this idea but how set the mapping rules for each attributes ?
>> > I expect the field-descriptor, bean-descriptor & collection-descriptor
>> > are still necessary if we uses the convertClass.
>> >
>>
>> This is a very good question to which unfortunately i don't have a good
answer. While a predefined
>> converter knows how to deal with a limitted set of properties/subnodes, on
the other side (e.g. on
>> objects world) those properties may come from really complex expressions.
>> There are a few possible approaches to solving this, but for the moment none
of them satisfies me:
>> - have the object implement an interface which responds to the needs of the
converter
>> (may be considered bad because it ties the object to the ojcrm tool)
>> - have the description provided through the same mechanisms of fd, bd or cd
>> (may be considered bad because the mapping becomes complex, and changes in
some way the semantics of
>> fd, bd and cd)
>> - create/reuse a object graph navigation language
>> (may be considered bad because the user should learn a new/the user should
use a new `language´)
>> - have the converter provide extension points so that in special cases an
user may extend it to
>> extract the values/populate the values
>>
>> Example:
>> 1/ in the simplest case where the object provides accessors to the object
properties according to
>> the needs of the converter than you don't need to detail the mapping (the
node property paths and
>> subnodes paths maps directly to object properties)
>> 2/ in more complex cases where the object needs special manipulation in
order to provide/to write
>> object properties, than the user should extend the converter and provide
access to those properties
>>
>> what do you think?
>>
>> ./alex
>> --
>> .w( the_mindstorm )p.
>>
>>
