JNLP puzzle

[Roedy Green]

The DTD for JNLP has a line like this:

<!ELEMENT jnlp (information+, security?, resources*,
(application-desc | applet-desc | component-desc |
installer-desc))>

Both tools I used to translate that into XSD suggested that you had to
pick only ONE of application-desc, applet-desc, component-desc,
installer-desc. I don't understand DTD well enough to know if the
DTD says that too.

If that is so, how do you ever do an installer? Don't you need BOTH an
say as application-desc and an installer-desc?

From a pragmatic point of view, I have done just that in
http://mindprod.com/webstart/espan.html, and it works, even though it
may technically be illegal.

What are you supposed to do? have two different JNLP files?

 

[Andrew Thompson]

The DTD forJNLPhas a line like this:

<!ELEMENTjnlp(information+, security?, resources*,
 (application-desc | applet-desc | component-desc |
 installer-desc))>

Both tools I used to translate that into XSD suggested that you had to
pick only ONE of application-desc, applet-desc, component-desc,
 installer-desc.  I don't understand DTD well enough to know if the
DTD says that too.

That agrees with my understanding.

What are you supposed to do?  have two different JNLP files?

Yes.

Some good reasons I can think of, to enforce
an installer to be a separate extension, is that if,
for example, you have one databsase used by
four separate apps.,
- it can help to factor out the DB install into
the single extension, and simply refer to it as
a single line in the 4 application-desc JNLP files.
- Also, an installer-desc would often require
all-permissions to do what is needed, whereas
2 of the four apps. might be deployable sandboxed.

Ultimately, I factor a lot of things into separate
JNLP files, from API parts to media archives. There
is a lot of sense to it.