- BaseX-Talk - mailman.uni-konstanz.de

Whitespaces not preserved in TEI documents.
by Montserrat Matías 06 Jul '23

06 Jul '23

Hello. I have a bug with BaseX version 10 and higher related to handling whitespaces in documents with mixed content elements. I'm working with narrative documents (TEI). Following the instructions in the documentation about this type of documents (containing mixed elements) I have disabled the indentation and the STRIPWS option. When I execute queries with connection to the database, the result is as explained in the documentation (blanks are preserved). However, when I use the BaseX libraries to execute queries in a local context (without a connection to the database) the spaces are sometimes removed. Same error if I run the query in the Database Administration interface. Query: db:option('stripws') Result: false Query: db:option('serializer') Result: map{"omit-xml-declaration":"yes","binary":"yes","method":"basex","use-character-maps":"","tabulator":"no","allow-duplicate-names":"no","media-type":"","doctype-public":"","escape-uri-attributes":"no","standalone":"omit","csv":map{"lax":true(),"backslashes":false(),"separator":"comma","allow":"","header":false(),"quotes":true(),"format":"direct"},"indents":2,"json-node-output-method":"xml","json":map{"escape":true(),"strings":false(),"lax":false(),"indent":(),"format":"direct","merge":false()},"doctype-system":"","item-separator":(),"indent":"no","suppress-indentation":"","byte-order-mark":"no","include-content-type":"yes","encoding":"UTF-8","newline":"\n","normalization-form":"none","html-version":"","version":"","limit":-1,"undeclare-prefixes":"no","cdata-section-elements":"","parameter-document":""} Query: let $doc := <doc><entry><sense id='1'><def>Gente grosera o vulgar.</def><cit><quote><seg>La</seg> <oRef>chusma</oRef>.</quote></cit></sense></entry></doc> return $doc/entry//sense[@id = '1'] Result: <sense id="1"><def>Gente grosera o vulgar.</def><cit><quote><seg>La</seg><oRef>chusma</oRef>.</quote></cit></sense> The whitespace contained between the </seg> and <oRef> tags has been stripped. In version 9.3.5 this problem did not occur. Can you please have a look at this? In a TEI document whitespaces are important. Thanx in advance, Montse. ___________________________________________ NOTA LEGAL El contenido de este mensaje de correo electrónico, incluidos los ficheros adjuntos, es confidencial y está protegido por el artículo 18.3 de la Constitución española, que garantiza el secreto de las comunicaciones. Si usted recibe este mensaje por error, le rogamos que se ponga en contacto con el remitente para informarle de este hecho y no difunda su contenido ni haga copias. La Real Academia Española informa de que los datos que en esta comunicación figuran, así como los que mantiene de usted y/o de su empresa, son tratados con la finalidad de mantener el contacto, así como de realizar las gestiones que en esta aparecen, y son utilizados de forma autorizada por las partes y sin cederse a terceros ajenos. Puede ejercer sus derechos a través de proteccion_de_datos(a)rae.es<mailto:proteccion_de_datos@rae.es>. Puede obtener más información sobre protección de datos en nuestra página web<https://www.rae.es/aviso-legal> o contactando directamente con nosotros (Reglamento UE 2016/679).

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Determining if a node is a database node
by Eliot Kimber 06 Jul '23

06 Jul '23

I need to be able to determine if an arbitrary node is or is not a database node. I implemented this function: declare function util:isDatabaseNode($node as node()) as xs:boolean { let $isDbNode as xs:boolean := try { let $nodeId as xs:integer? := db:node-id($node) (: let $msg := prof:dump(``[[DEBUG] relpath:isDatabaseNode(): nodeId: "`{$nodeId}`"]``) :) return exists($nodeId) } catch * { (: let $msg := prof:dump(``[[DEBUG] relpath:isDatabaseNode(): Got exception `{$err:code}` - `{$err:description}`]``) :) (: return :) false() } let $msg := prof:dump(``[[DEBUG] relpath:isDatabaseNode(): Returning `{$isDbNode}``]``) return $isDbNode }; With the prof:dump() calls commented out as shown here, it always returns true, even when it returned false. If I comment in the prof:dumps then I get the expected correct false result. This must be the result some optimization at compile time but I haven’t been able to find a construction of this function that works without the debug messages. Is there a better way to determine if a node is a database node? This is with 10.6. Cheers, E. _____________________________________________ Eliot Kimber Sr Staff Content Engineer O: 512 554 9368 M: 512 554 9368 servicenow.com<https://www.servicenow.com> LinkedIn<https://www.linkedin.com/company/servicenow> | Twitter<https://twitter.com/servicenow> | YouTube<https://www.youtube.com/user/servicenowinc> | Facebook<https://www.facebook.com/servicenow>

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Possible bug in the interaction between db:attribute(), data() and Sequences.
by Andreas Hengsbach | nexoma 05 Jul '23

05 Jul '23

Hello all, we have probably found a bug, the cause of which is currently unclear to us. Fortunately, the problem is reproducible in a small test case. Steps to reproduce the problem: 1. import the following XML into a BaseX database "testcase". ### schnipp <attributes foo="bar"> <attribute name="test1" seq="foo"/> <attribute name="test2"/> <attribute name="test3" seq="bar"/> </attributes> ### schnapp 2. make sure that an attribute index has been created. 3. execute the following script. ### schnipp let $source := db:attribute('testcase', 'bar', 'foo')/.. let $value := ( $source/attribute[@name="test1"]/@seq/data(), $source/attribute[@name="test2"]/@seq/data(), $source/attribute[@name="test3"]/@seq/data() ) return ( $value[2] => inspect:type() ) ### schnapp Explanation: The example is really only meant as a test case. For our case we have already found a workaround, so we don't have a serious problem. The important thing is that the element is read from the database via db:attribute() and then the individual values are combined again into a sequence. In doing so, we get an untypedAtomic from attribute test1, an empty-sequence() for test2 and an untypedAtomic again for test3. Observation: When we read the second value of the sequence by index ($value[2]), we get back an "attribute()" instead of an untypedAtomic. Expectation: We would expect an untypedAtomic here again. Workaround: We simply used string() instead of data() to explicitly cast the value to a string. Versions: We were able to reproduce the problem with 10.4 and the current 10.6. With a very old version 7.9, however, it was not reproducible. Many thanks and best regards Andreas

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Performance of db:get-value() for large maps
by Eliot Kimber 03 Jul '23

03 Jul '23

I’m working on constructing DITA key spaces for our content. My current implementation builds an XQuery map that contains the key space data as well as the XML data from which the key space was constructed, which can be quite a bit (1-2 megabytes of XML all told—key space construction effectively requires constructing a single “resolved” DITA map from a tree of map documents, which I’m then storing in my key space map). A given key space might have 100,000 individual name-to-element mappings in addition to the raw DITA content. I tried saving these maps into a database using db:put-value(), which worked. But, when I went to fetch them back out, it took 30 seconds to fetch one of these maps. My expectation was that retrieving a map would be quite fast. I’m sure that it was silly to try to store all the raw markup in these maps, and I will change that aspect of my implementation to store the resolved maps separately and then use node IDs in the key space map. Worst case I can do what I have been doing with BaseX 9 and convert the XQuery map to an XML representation and use that for retrieval, which of course will work fine, at the cost of more code and a few more milliseconds of ingestion processing. Before I spend any more time trying to optimize the storage and retrieval of these maps, I wanted to ask a few questions: 1. Is my expectation that map retrieval should generally be very fast correct, modulo not having gobs of raw XML in them? 2. Is there a more efficient way to query over maps that are stored in a database? My initial attempt was to simply pull the entire map from the database and then operate on it as I would any other map, i.e.: $keySpace as map(*) := getKeySpace($rootMap) (: Pulls the map from the database :) $keydefs as element()* := $keySpace?keyscopes?($scopeKey)?keydefs?($keyName) 3. Is there some other maps-in-a-database optimization technique I’m overlooking? Thanks, Eliot _____________________________________________ Eliot Kimber Sr Staff Content Engineer O: 512 554 9368 M: 512 554 9368 servicenow.com<https://www.servicenow.com> LinkedIn<https://www.linkedin.com/company/servicenow> | Twitter<https://twitter.com/servicenow> | YouTube<https://www.youtube.com/user/servicenowinc> | Facebook<https://www.facebook.com/servicenow>

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Calling a Java function with varargs parameter from XQuery
by Lizzi, Vincent 03 Jul '23

03 Jul '23

Hello BaseX people, The Java language bindings in BaseX look like a very good way to use Java libraries from XQuery. I'm currently trying to use Lingua (https://github.com/pemistahl/lingua) with BaseX, and mostly have it working, but I've not been able to figure out how to call a Java function that takes a vararg (variable arguments) parameter. Here is a bit of XQuery code that shows the problem. I'm using BaseX version 10.6 and the jar for Lingua version 1.2.2 has been added to the classpath. This query should return a LanguageDetectorBuilder object. declare namespace Builder = "java:com.github.pemistahl.lingua.api.LanguageDetectorBuilder"; declare namespace Detector = "java:com.github.pemistahl.lingua.api.LanguageDetector"; declare namespace Language = "java:com.github.pemistahl.lingua.api.Language"; let $builder := Builder:fromLanguages( [ Language:ENGLISH(), Language:DUTCH(), Language:GERMAN(), Language:SPANISH(), Language:FRENCH() ] ) return $builder The above code produces this error message in the BaseX GUI: [XPTY0004] com.github.pemistahl.lingua.api.LanguageDetectorBuilder:fromLanguages(com.github.pemistahl.lingua.api.Language[]) expected, (CArray) found. If I try making the parameter a sequence instead of an array, replacing () parenthesis for the [] brackets, then this is the error message: [XPTY0004] com.github.pemistahl.lingua.api.LanguageDetectorBuilder:fromLanguages(com.github.pemistahl.lingua.api.Language[]) expected, (List) found. I've read through the Java Bindings page in the wiki and tried to rewrite the parameter in different ways, but so far have only gotten different error messages. The signature for the fromLanguages function can be seen at https://github.com/pemistahl/lingua/blob/main/src/main/kotlin/com/github/pe… Is there a way to make this work? Thanks, Vincent ______________________________________________ Vincent M. Lizzi Head of Information Standards | Taylor & Francis Group 530 Walnut St., Suite 850, Philadelphia, PA 19106 E-Mail: vincent.lizzi(a)taylorandfrancis.com<mailto:vincent.lizzi@taylorandfrancis.com> Web: www.tandfonline.com<http://www.tandfonline.com> Taylor & Francis is a trading name of Informa UK Limited, registered in England under no. 1072954 "Everything should be made as simple as possible, but not simpler." Information Classification: General

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Prolog and XQuery
by Ben Engbers 29 Jun '23

29 Jun '23

Hi, My ultimate goal is to investigate the advantages of using Prolog and XQuery together when querying XML files. In doing so, I want to take advantage of BaseX's XQuery engine. Since there is no Prolog client, I initially started writing a Prolog client. But in SWI-prolog, I did not manage to connect using the webconnection tools. So I first started to write a C++ client and then start writing a bridge in Prolog that uses that client. The starting point for the C++ client was the RBaseX client I published earlier. I converted all functionalities from that client to C++. A preliminary version of the C++ client can be found at https://github.com/BenEngbers/BasexCpp. As soon as I manage to create a real shared object using CMake I will publish a final version. Regarding the server protocol for BaseX, however, I still have a question. According to that protocol, the ADD command accepts 4 arguments ({09 {name} {path} {input} ). However, neither in R nor in C++ have I succeeded in using the {name} argument. My question is whether this is a bug in the protocol? I don't know if there is a need for a C++ client that implements the full server protocol but in any case I enjoyed working on this project. Have fun, Ben Engbers

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Setting up redirects and https
by Eliot Kimber 28 Jun '23

28 Jun '23

I have a “production” BaseX server for our Mirabel system that is currently served on the old 8984 port. As it’s a dedicated server, I would like to serve it on port 80. But I also have users who use the current port, and I don’t want to disrupt them more than necessary when I make this change. I’d also like to start serving using HTTPS. Is there an easy way to set up a redirect from the old port to the new port? What is involved in serving BaseX over HTTPS? I’m using the built-in Jetty server and I suspect the answer is in the Jetty docs but I thought I’d ask here first before seeing of ChatGPT can get me close to a solution. Thanks, Eliot _____________________________________________ Eliot Kimber Sr Staff Content Engineer O: 512 554 9368 M: 512 554 9368 servicenow.com<https://www.servicenow.com> LinkedIn<https://www.linkedin.com/company/servicenow> | Twitter<https://twitter.com/servicenow> | YouTube<https://www.youtube.com/user/servicenowinc> | Facebook<https://www.facebook.com/servicenow>

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Dynamic path segment for websockets
by Marco Lettere 28 Jun '23

28 Jun '23

Dear all, so I just found out that it is not possible to create websockets bound to dynamic paths. If I try a websocket connection to declare %ws:connect('/notification/subject/{$subject}') function log:subject() {}; I get an error (without significant logs). Whereas declare %ws:connect('/notification/subject/one') function log:subject() {}; works well. Does this have a motivation? Is there another way of meeting the requirement of having dynamic websocket channels? Thanks in advance, Marco.

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Values stored to a database vs using the new store
by Eliot Kimber 28 Jun '23

28 Jun '23

I’m coming up to speed on BaseX 10 and trying to understand the practical difference between using the built-in store (or a custom store) and simply saving values into a database. As far as I can tell from the docs the basic feature is the same: given e.g., a map with stuff in it, I can store the map to a database with the new db:put-value() function or to the build-in store (or a custom store) using store:put() and in both cases can get the map back. Given that the store is automatically persistent, it seems like the obvious choice if you’re using maps as a result caching technique, so I’m wondering what the reasons would be for not using it and using a database instead. I think the answer includes: * Databases provide locking semantics that the store does not—the store docs are clear that the store is non-deterministic and may have side effects. So if you need to ensure locking consistency, you want to use a database. * Custom stores require that you manage any required persistence yourself, while databases are inherently persistent. Have I missed any other important considerations? Without taking the time to do the measuring, I’m guessing that there is negligible performance difference between using the store and a database—I’d be very surprised if the underlying implementation was not based on the same code. In our Project Mirabel system I need to do caching of large query results, so being able to quickly and conveniently store maps is ideal and I’m very excited to take advantage of this new feature. Cheers, E. _____________________________________________ Eliot Kimber Sr Staff Content Engineer O: 512 554 9368 M: 512 554 9368 servicenow.com<https://www.servicenow.com> LinkedIn<https://www.linkedin.com/company/servicenow> | Twitter<https://twitter.com/servicenow> | YouTube<https://www.youtube.com/user/servicenowinc> | Facebook<https://www.facebook.com/servicenow>

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Variable value
by Giuseppe G. A. Celano 19 Jun '23

19 Jun '23

Hi, I have stambled upon an unexpected issue concerning the value of a variable (in BaseX 10.6), which seems to be affected by an independent function. I have a function like page:open-url($an1) which takes a url as a parameter and opens a document. The url usually consists of an invariable part + a final number that identifies different documents. If I only pass the final number of the url, the function, as expected, returns an error (because it tries to resolve a relative path pointing to no document). However, if I change the script into let $f := page:documents($an1, $an2) return page:open-url($an1) the function page:open-url($an1) works properly (i.e., the presence of the independent let clause seems to affect the value of the variable $an1): I would not expect this in a functional programming language like XQuery. I have posted a gist here [1], where there are more details (look at the very end of the script) Ciao, Giuseppe —— [1] https://gist.github.com/gcelano/31ef1880ac8439398c7f6de1de6d78d3

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