Thanks Tom for your suggestions!
I was hoping to use a standard mechanism, but your tricks are
attracting... Hard to make the right choice.
Camille.
Thomas Schraitle wrote:
> Hi Camille,
>
> On Saturday 08 October 2005 13:40, Camille Bégnis wrote:
>
>>[...]
>>So I thought of using the xinclude plus xpointer mechanism in order to
>>pick the "entities" in a real XML file instead. The problem is that the
>>xinclude syntax is quite verbose, so replacing &docbook; with
>><xi:include href="entities.xml xpointer="docbook"
>>xmlns:xi="http://www.w3.org/2001/XInclude" /> makes the XML code
>>significantly harder to read.
>>
>>So I am interested in any experience in this area.
>>If you have another idea than xinclude, I'll be happy to hear it as
>>well.
>
>
> If you look for another solution you should consider some parameters:
>
> * How much control by DTD/schema?
> * Flexibility
> * Verbosity
> * Extensibility
>
> There are a number of different methods to use, each have advantages and
> disadvantages, of course:
>
> 1. Processing instructions (PIs)
> You can use something like
>
> <para>Use <?dbentity entity="foo"?> to ...</para>
>
> Advantages:
> - A bit less verbose than XIncludes
> - Writer have freedom to choose from different "sets"
> - Very extensible and flexible
> - It doesn't require to change the DTD/Schema
>
> Disadvantages
> - Freedom is sometimes not always useful. Think of writers who
> should use restricted values only (XML editors).
> - There is no validation for PIs, e.g. you can not restrict
> values. You can check the correct values only in the XSLT
> step, for example
> - "Entity replacement" must be resolved by another step
> - PIs shouldn't be use for content only
>
>
> 2. (Ab)use of an exisiting element
> You could use an element with a "special" attribut. In case of DocBook you
> could use the element phrase. For example:
>
> <para>Use <phrase role="entity:foo"/> to ... </para>
>
> Advantages:
> - Less verbose than XInclude
> - DTD can restrict the possible values
> - phrase can occur on allowed content only
> - XML editors can offer writers the set of possible values
>
> Disadvantages:
> - You have to change the DTD/Schema to add all possible
> attribute values
> - The semantic of phrase doesn't really fit
> - It might conflict with other content for phrase (processing
> might be a bit complicated)
> - It must be resolved by another step
>
>
> 3. Introduce new element
> It is a variation of point 2: Insert a new element just for this purpose.
> For example:
>
> <para>Use <e:entity name="foo"/> to ... </para>
>
> Advantages:
> - Less verbose than XInclude
> - DTD/Schema can restrict possible values
> - XML editors can offer writers the set of possible values
>
> Disadvantages:
> - You have to change the DTD/Schema
> - Complicates the content modell in case of DTD
> - It must be resolved by another step
>
> What is the best solution? I don't know. It is up to you. :-)
>
>
> Tom
>
