Re: [basex-talk] Basex xquery import module classpath lookup

Is there anything else I can do to help?

Karel On 13/04/2015 10:15, Karel Hovorka wrote:

Hello Johan and Christian,

this is the simpliest snippet, that I am using to run xquery (without giving it any input xml):

    System.setProperty("org.basex.QUERYPATH", 

“/workspace/project/src/main/resources/xquery/");

    Context context = new Context();
    LocalSession session = new LocalSession(context);
    session.setOutputStream(System.out);

    String xq = 

IOUtils.toString(getClass().getResourceAsStream("/xquery/test.xq"), StandardCharsets.UTF_8); LocalQuery query = session.query(xq); query.next();

As you can see, I am setting QUERYPATH and looking files on filesystem, where they are in the project, which works fine for development, but cannot work in production, because files will be in jar or war.

I would imagine this snipped to be changed to something like this:

    //System.setProperty("org.basex.QUERYPATH", 

“/workspace/project/src/main/resources/xquery/");

    Context context = new Context();
    context.setURIResolver(new DefaultURIResolver() {
        //Signature same as org.basex.io.IO.get
        public IO resolve(String resource) {
            InputStream in = 

getClass().getResourceAsStream("/xquery/" + resource); if (in != null) { return new IOStream(in, "/xquery/" + resource); } //fallback, default resolver, basically current IO.get return super.resolve(resource); } }); LocalSession session = new LocalSession(context); session.setOutputStream(System.out);

    String xq = 

IOUtils.toString(getClass().getResourceAsStream("/xquery/test.xq"), StandardCharsets.UTF_8); LocalQuery query = session.query(xq); query.next();

Not sure, if Context class is the best location for setURIResolver method, but makes sense to me, because uriresolver should be part of a context (not referencing class).

Hope it helps,

Karel

On 11/04/2015 08:40, Christian Grün wrote:

...

Hi Karel, hi Johan,

I can see that there is some demand for such an extension. However, I still know too less about it in order to make it work the right way. Could you please both give me a little code example how you would like to see the feature embedded in the BaseX APIs you are using?

Thanks in advance, Christian

On Sat, Apr 11, 2015 at 1:56 AM, Johan Mörén johan.moren@gmail.com wrote:

...

Support for this would be really great if it does not exist yet. I'm running a lot of queries in embeded mode and would like to extract some functions to modules that multiple queries can share to reduce code duplication.

Making it possible to give the query processor a customizable URIResolver would be great since we package our resources in .jar files on deployment.

Regards, Johan Mörén

On Thu, Apr 9, 2015 at 6:13 PM, Karel Hovorka Karel.Hovorka@semantico.com wrote:

...

We always use custom URIResolver when working with classpath resources afaik.

Similar mechanism might be better than original feature for reasons you stated (duplicity in classpath). You can solve this by choosing correct classloader in *URIResolver.

I've been digging a little into BaseX source and I've found org.basex.io. IO.get method, which does similar thing (loading resource based on string). If this factory method replaces by a customizable factory with default implementation, that might solve the problem. However I know very little about BaseX, and I may be completely wrong here.

Karel

On 09/04/2015 16:47, Christian Grün wrote:

Thanks for the links. If I get it right, you need to explicitly call the URI resolver setter functions to get it working? Or does it mean that modules will automatically be available via "import module" if they are in the Java classpath (which is, if I got it right, the feature you asked for)?

On Thu, Apr 9, 2015 at 5:02 PM, Karel Hovorka Karel.Hovorka@semantico.com wrote:

Exactly, I am refering to "import module". In my experience with xml-related technologies and java, library usually supports customizable class for import resource lookup based on namespaces, paths etc, I can recall 2 examples:

Saxon has class ModuleURIResolver that does just this:

http://www.saxonica.com/html/documentation/javadoc/net/sf/saxon/s9api/XQuery...

Similar class URIResolver and mechanism is in java core for xsl:import/xsl:include lookup:

http://docs.oracle.com/javase/7/docs/api/javax/xml/transform/TransformerFact...

Thanks, Karel

On 09/04/2015 15:41, Christian Grün wrote:

I would like to load xquery files that are on classpath of my java application, not only filesystem. Does this mean, it is not possible with BaseX?

Do you refer to the "import module" when talking about loading xquery files?

The classpath is not considered when importing modules. As multiple directories can be specified in the classpath, it could even happen that different modules would be import candidates, so we'd need additional precedence rules. -- Is this possibly supported by any other query processor you have tried?

Best, Christian

Karel

On 08/04/2015 18:01, Christian Grün wrote:

Hi Karel,

In BaseX, modules either need to be located in the module repository, or the relative path needs to be specified in the import module statement. Some more information on locating modules can be found in our Wiki [1].

Hope this helps, Christian

[1] http://docs.basex.org/wiki/Repository

On Wed, Apr 8, 2015 at 5:56 PM, Karel Hovorka Karel.Hovorka@semantico.com wrote:

Hi,

I am trying to run xquery file on basex, but it depends on xquery module located in classpath. I have found parameter "org.basex.QUERYPATH", that configures module lookup on filesystem. Is there way to lookup modules in classpath?

Thanks,

Karel Hovorka, Semantico LTD