Hi Christian, Thanks for your answer and for taking our feature request into consideration.
You propose to use xquery:eval, as long as we don't perform any updates (which is the case). But the documentation of this function mentions that two errors can be raised : in case of updates and when the evaluated expression yields function items. How should we understand this second limitation? Because modules precisely define functions... Best, Jean-Philippe On Mon, Feb 24, 2014 at 10:59 AM, Christian Grün <[email protected]>wrote: > Hi Jean-Philippe, > > thanks for your describing your use case. I've recently thought about > such an import-module function. It's not completely trivial, because a > dynamic import function may result in the import of other modules, > some of which may already have been statically imported, and so on. > But I have added an issue to remember your feature request... > > https://github.com/BaseXdb/basex/issues/869 > > ...and I'll give you notice as soon as we have time to tackle this one. > > In the meanwhile, the use of xquery:eval may be one way out, as long > as you don't have to perform any updates. > > Feel free to ask for more, > Christian > > > On Mon, Feb 24, 2014 at 10:40 AM, Jean-philippe Magué > <[email protected]> wrote: > > Hi Christian, > > > > I repoen this discussion about dynamic module loading. This issue is > getting > > more and more blocking for us. Let me try to re-expain our needs. > > We've written a restXQ based webapp extendable with a plugin based > > mechanism, where plugins modules provide functions to be called from a > main > > module. But to be able to call a plugin function from the main module, > the > > plugin module has to be imported by the main module. As far as we know, > this > > can only be done with a import module staetment. Thus, users who have > > installed our webapp and who want to install plugins have to dig into the > > xquery code to add these import statements. Even with a good > documentation, > > for non technical users, this is to much to ask. If we could dynamically > > import modules with a function similar to exist's util:import-module, the > > plugin installation process would be dramatically simplified. > > Do you have any plan to implement such a function ? Or is there any > > workaround we could use ? > > > > Best, > > > > Jean-Philippe > > > > > > On Fri, Jun 21, 2013 at 4:43 PM, Christian Grün < > [email protected]> > > wrote: > >> > >> Hi Jean-Philippe, > >> > >> thanks for providing us with the (concise) details. > >> > >> In our existing RESTXQ projects, we directly decorate all executable > >> functions with specific %rest:path annotations; this way, there is no > >> need for an additional "dispatcher" function that delegates a call to > >> a specific module or function. You can dynamically add and remove > >> modules to your web application, as all .xqm files will automatically > >> be parsed for restxq annotations before each query execution. Next, > >> the implementation is smart enough to only parse code that has ben > >> changed, so you shouldn't encounter any bottlenecks even when working > >> with hundreds of restxq modules. But I'm not sure if adding modules > >> with restxq entry points is a reasonable alternative for your > >> approach? > >> > >> Your feedback is welcome; feel free to ask for more details, > >> Christian > >> ___________________________ > >> > >> 2013/6/21 Jean-philippe Magué <[email protected]>: > >> > Dear Christian, > >> > > >> > Thanks for your response. I'm going to try be more specific, but to > >> > remain > >> > concise. > >> > > >> > In our restxq application, we have one "main" module and several > >> > "dependent" > >> > modules. The main module receives the http requests (well, it declare > >> > functions annotated with a path, say ourApp/{$param}), and calls > >> > functions > >> > in one of the dependent module. This dependent module is determined by > >> > the > >> > path : a request to ourApp/moduleA will cause the main module to use > >> > functions in the moduleA dependent module, while a request to > >> > ourApp/moduleB > >> > will cause it to call functions in the moduleB dependent module. > >> > > >> > It works just well if we import all the dependent modules in the main > >> > module > >> > using the regular way, with import module statements. Yet, we want to > go > >> > one > >> > step forward and import the dependent modules only when/if needed. > More > >> > precisely, we'd like to be able to add new dependent modules in the > >> > restxq > >> > directory without having to modify the main module by adding new > import > >> > module statements. > >> > > >> > But it's probably some kind of inappropriate perfectionism that isn't > >> > worth > >> > spending much time ! > >> > > >> > Best, > >> > > >> > Jean-Philippe > >> > > >> > PS: Thanks for looking at the circular import issue. Having our > >> > dependent > >> > modules importing back the main module would be very helpful! > >> > > >> > > >> > On Thu, Jun 20, 2013 at 10:44 PM, Christian Grün > >> > <[email protected]> > >> > wrote: > >> >> > >> >> Dear Jean-Philippe, > >> >> > >> >> as you correctly guessed, there is no function in BaseX for > >> >> dynamically importing XQuery modules. The function xquery:invoke [1] > >> >> may serve a similar purpose. I'm not sure how the invocation of Java > >> >> code could help here, so could you give us some more information on > >> >> what you plan to do, and what needs to be done at runtime in your > >> >> scenario? > >> >> > >> >> Thanks, > >> >> Christian > >> >> > >> >> PS: our team member Leo is currently having a look at the circular > >> >> module import issue. > >> >> > >> >> [1] http://docs.basex.org/wiki/XQuery_Module#xquery:invoke > >> >> ___________________________ > >> >> > >> >> > Exist-db has an util:import-module function that allows to > >> >> > dynamically > >> >> > import an XQuery module at run time. I haven't found anything > >> >> > equivalent > >> >> > in > >> >> > BaseX. Is that right ? > >> >> > > >> >> > I have also tried to see how to implement such a function directly > in > >> >> > Java, > >> >> > but as far as I understand the module parsing process, functions > >> >> > prefix > >> >> > are > >> >> > checked at compile time. That would compromise any attempt to write > >> >> > such > >> >> > a > >> >> > function. Am I right ? > >> >> > > >> >> > Best, > >> >> > > >> >> > Jean-Philippe > >> >> > > >> >> > > >> >> > -- > >> >> > Jean-Philippe Magué > >> >> > Maître de Conférences en Humanités Numériques > >> >> > Responsable de l'Atelier des Humanités Numériques : > ahn.ens-lyon.fr > >> >> > Ecole Normale Supérieure de Lyon > >> >> > +33 (0)4 26 23 38 08 > >> >> > > >> >> > -- > >> >> > > >> >> > "Using computers will therefore lead us to a more profound and > >> >> > systematic > >> >> > knowledge of human expression; in principle, it can help us to be > >> >> > more > >> >> > humanistic than before." > >> >> > Busa, 1980. > >> >> > > >> >> > _______________________________________________ > >> >> > BaseX-Talk mailing list > >> >> > [email protected] > >> >> > https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk > >> >> > > >> > > >> > > >> > > >> > > >> > -- > >> > Jean-Philippe Magué > >> > Maître de Conférences en Humanités Numériques > >> > Responsable de l'Atelier des Humanités Numériques : ahn.ens-lyon.fr > >> > Ecole Normale Supérieure de Lyon > >> > +33 (0)4 26 23 38 08 > >> > > >> > -- > >> > > >> > "Using computers will therefore lead us to a more profound and > >> > systematic > >> > knowledge of human expression; in principle, it can help us to be more > >> > humanistic than before." > >> > Busa, 1980. > > > > > > > > > > -- > > Jean-Philippe Magué > > Maître de Conférences à l'Ecole Normale Supérieure de Lyon > > +33 (0)4 37 37 63 13 > -- Jean-Philippe Magué Maître de Conférences à l'Ecole Normale Supérieure de Lyon +33 (0)4 37 37 63 13
_______________________________________________ BaseX-Talk mailing list [email protected] https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk
