| 540 | | == Possible namespace pollution: Ticket 348 to be discussed with Peter == |
| 541 | | |
| 542 | | See [https://trac.clarin.eu/ticket/348] |
| 543 | | |
| 544 | | Peter: |
| 545 | | "It looks like there might be some namespace pollution or some other anomaly that causes the jaxb a |
| 546 | | uto generated classes to omit the getter for notebooks from the ObjectFactory. This is an issue |
| 547 | | when a jaxb root node is required, such as in the rest interface. A work around has been added |
| 548 | | which makes it clear where the issue is and why the ObjectFactory is required, but this needs to |
| 549 | | be replaced when the schema is updated."[[BR]] |
| 550 | | [[BR]] |
| 551 | | ''Stephanie:'' If indeed, the issue lies with the plural forms of complexType names (used for lists of resources) in the schema, we think that, principally, the plural forms can - and should - be replaced more or less immediately, e.g. by adding the suffix "{{{List}}}" or "{{{Collection}}}" instead of plural "s". For instance, the serialized xml output could then match the following snippet |
| 552 | | {{{ |
| 553 | | <annotationCollection> |
| 554 | | <annotation> |
| 555 | | <!-- elements of annotation --> |
| 556 | | </annotation> |
| 557 | | </annotationCollection> |
| 558 | | }}} |
| 559 | | |
| 560 | | |
| 561 | | |
| 562 | | By the way, speaking of diverse "JAXB plural issues", there were some hints on the web regarding (inline and external) Java binding customization for JAXB, - it might be that this would also be a viable solution approach. Maybe this thread is worth checking as well: http://stackoverflow.com/questions/11943487/please-advise-the-best-pattern-for-serialising-jaxb-lists? |
| 563 | | |
| 564 | | ''Olha'': we agree. See also the updated comments for the ticket 348. |
| 565 | | |
| 566 | | As regards all future schema updates, please make sure to remember to update all available scenario xml documents on trac.clarin.eu accordingly, and preferably, with as little delay as possible. It might also be a good idea to validate all of these documents against the revised schema with a reliable XML parser like e.g. the Xerces-J XML parser. Also, if you like, you can check by validating some of our current "real-life" mock xml documents that we have been using recently for client development ([source:DASISH/t5.6/client/trunk/chrome/markingcollection/content/markingcollection/annotator-service/test/mockjax/mocks]). |
| 567 | | |
| 568 | | ''Olha'': sure. We have not made any changes yet (before getting you opinion). Unfortunately, I will be away 27/08 - 14/09 due to urgent family circumstances. I hope that we can wait till I'm back. |
| 569 | | |
| 570 | | === Resolution === |
| 571 | | |
| 572 | | The schema is to be fixed. The current hypothesis is that JAXB get confused by plural forms used in the schema in type names for lists of resources, |
| 573 | | e.g. Annotation --> Annotations, Notebook --> Notebooks etc. Replace plural forms with other wording and check if it fixes the problem. |
| 574 | | |
| 575 | | |
| 576 | | == New-Or-Existing-Source-Info JAXB-generated class == |
| 577 | | |
| 578 | | This class corresponds to the choice sub-schema within the schema-type for annotation, which tells if a target source is new or old. This means that |
| 579 | | the client provides the server with this information. |
| 580 | | |
| 581 | | It is ok, but it makes code a bit hairy. Can we remove the choice and let the backend todecide if the source is new or old, simply by looking through all the sources |
| 582 | | to find the one with given external-id/uri. If it is not found then the source is new. |
| 583 | | [[BR]][[BR]] |
| 584 | | ''Stephanie:'' Both Olof and I are somewhat unsure whether it is really necessary to differentiate between new and existing sources when sending POST, PUT, DELETE and GET requests from within the client, especially if the backend implementation is going to be changed to simply check whether the given URI already exists in the DB or not. |
| 585 | | Could you please rethink whether we actually need to keep this concept in the schema document, DASISH-schema.xsd? This decision also has consequences for how the behavior of the client needs to be tuned (cf. [source:DASISH/t5.6/client/trunk/chrome/markingcollection/content/markingcollection/annotator-service/test/mockjax/mocks POST/GET] mock docs named above). |
| 586 | | |
| 587 | | ''Olha'': we agree with you. See resolution below. |
| 588 | | |
| 589 | | === Resolution === |
| 590 | | |
| 591 | | The schema must be simplified. It is up to server to decide if a source is new or old. See ticket https://trac.clarin.eu/ticket/362 for more detail. |
| 592 | | |
| 593 | | |
| 594 | | == External_id (Data Base) vs URI (schema) vs UUID-based class (Java code) == |
| 595 | | |
| 596 | | For the time being I treat {{{extrnal_id}}} and the URI as "the same": URI is external_id. Both are strings. |
| 597 | | |
| 598 | | In the Java-code there are classes {{{{CachedIdentifier, VersionIdentifier, SourceIdentifier, AnnotationIdentifier, NotebookIdentifier, UserIdentifier}}} |
| 599 | | encapsulating UUI. Any such class has a string field "identifier" (corresponding to external_id) plus hash, plus internal constants for hash. |
| 600 | | [[BR]][[BR]] |
| 601 | | ''Stephanie:'' Apropos this subject, could you please clarify whether you intend to use "external-id (Ticket #362: externalID, see even discussion topic above)" for the database only? You use the wording "For the time being", which made us wonder whether the statement "URI is external_id" will be true even in the longer perspective, or, if not, where / how the externalID is going to be put in from the schema side, an thus within the context of the resulting, serialized xml documents? Furthermore, why is the nomenclature "external_id" used? Won't the value of URI always be an internal id, like e.g. http://dasish.eu/annotations/AID20130808114716, that needs to be created and set via a corresponding backend functionality? |
| 602 | | |
| 603 | | ''Olha'': The term "external_id" comes from the Data Base and is used for communication with the client. It is a string which satisfies UUID-format, e.g. "00000000-0000-0000-0000-000000000003". The URI in the xsd is of the form like you mentioned above e.g. http://dasish.eu/annotations/00000000-0000-0000-0000-000000000003. An external Id is generated by the backend whenever a resource is recognized as new in the corresponding "add"-method. It is sent to the client as a respond to the "Add" request. Just to be sure, we definitely intend to keep it this way although there should be no need for the client to be aware of the conceptual distinction between 'external id' and the URI, in other words the latter can be considered the public identifier for the client. |
| 604 | | |
| 605 | | "Internal_id" in the database is not visible to a client. It is "next-in-the-table" number generated by the database whenever the corresponding resource is added. It is a primary key of the resource. It is used for joint tables (e.g. when you connect an annotation to a source) and for quick search by key, since it is just a number, not a string. |
| 606 | | |
| 607 | | Also, the ticket 371 mentioned below is fixed. |
| 608 | | |
| 609 | | === Resolution === |
| 610 | | |
| 611 | | The schema stays intact. For the back-end code: the URI must be of the form "http(s):/<dasish-server>/externalID. See https://trac.clarin.eu/ticket/363 for more detail. |
| 612 | | |
| 613 | | Moreover, all {{{{CachedIdentifier, VersionIdentifier, SourceIdentifier, AnnotationIdentifier, NotebookIdentifier, UserIdentifier}}} must be removed. We will be using just UUID type |
| 614 | | for all identifiers of any sort of resource. E.g. UserIdentifier userIdentifier = New UserIdentifier("00000000-0000-0000-0000-000000000003") will be replaced with |
| 615 | | UUID userIdentifer = UUID.fromString("00000000-0000-0000-0000-000000000003"). It is the ticket https://trac.clarin.eu/ticket/371. |
| 616 | | |
| 617 | | |
| 618 | | |
| 619 | | == Body: must be some serialization/deserialization mechanism == |
| 620 | | |
| 621 | | -- "body" in the DB is just a text |
| 622 | | |
| 623 | | -- "body" in JAXB-generated class is a list of objects |
| 624 | | |
| 625 | | For now, I use simple "serialize" and "deserialize" Helpers' procedures which should be replaced by some proper marshalling-demarshalling. For simple serialization I treat the first element of the list |
| 626 | | of objects above as a text whcich corresponds to the DB column "body_xml". |
| 627 | | |
| 628 | | === Resolution 18/09 === |
| 629 | | |
| 630 | | The schema is updated (contrary to what was stated before 18/09). See https://trac.clarin.eu/ticket/364 for more detail, the comment on it. |
| 631 | | [[BR]][[BR]] |
| 632 | | ''Stephanie:'' It might be preferable to abandon the helper methods in favor of using JAXB's marshal() and unmarshal() methods together with a(n) {{{Marshaller}}} / {{{Unmarshaller}}} object. Can JAXB's {{{ObjectFactory}}} methods be of any use as an alternative way to access XML data? Furthermore, you might want to have a look at Javax.xml.bind.JAXBIntrospector.getValue(Object jaxbElement). Please see: http://www.tutorialspoint.com/java/xml/; http://www.oracle.com/technetwork/articles/javase/index-140168.html; http://docs.oracle.com/javase/tutorial/jaxb/intro/index.html; http://jaxb.java.net/tutorial/ - in case you haven't come across these web resources before. |
| 633 | | |
| 634 | | "Olha": the helpers "serialize/deserialize" are removed. We have to discuss at Goteborg our present solution |
| 635 | | |
| 636 | | {{{ |
| 637 | | <xs:complexType name="AnnotationBody"> |
| 638 | | <xs:simpleContent> |
| 639 | | <xs:extension base="xs:string"> |
| 640 | | <xs:attribute name="mimeType" type="xs:string"/> |
| 641 | | </xs:extension> |
| 642 | | </xs:simpleContent> |
| 643 | | </xs:complexType> |
| 644 | | }}} |
| 645 | | |
| 646 | | The database is changed so that the column "body_xml" in the table "annotation" is replaced with two ones: "body_text" and "body_mimetype". The corresponding adjustments in the code and in the unit tests are done. So far, no special serialization menachisme is used. |
| 647 | | |
| 648 | | The question: what does the client need to do to be able to represent the annotation body properly? |
| 649 | | |
| 650 | | == Source == |
| 651 | | |
| 652 | | Misprint in timeStamp: timeSatmp. |
| 653 | | |
| 654 | | === Resolution === |
| 655 | | |
| 656 | | The schema must be fixed. See https://trac.clarin.eu/ticket/365 |
| 657 | | |
| 658 | | == Cached Representation Info == |
| 659 | | |
| 660 | | Missing in the schema: the attribute/elememt "where_is_the_file" which actually points to the location |
| 661 | | where the file can be download. It is necessary to fulfill |
| 662 | | |
| 663 | | GET api/sources/<sid>/cached/<cid>/content |
| 664 | | |
| 665 | | === Resolution === |
| 666 | | |
| 667 | | The schema stays intact. For the back-end (and the database!): the cached representation for now should be stored in the database |
| 668 | | as a BLOB. See: http://dba.stackexchange.com/questions/803/blobs-or-references-in-postgresql/815#815. |
| | 540 | |
| | 541 | As regards all future schema updates, please make sure to remember to update all available scenario xml documents on trac.clarin.eu accordingly, and preferably, with as little delay as possible. It might also be a good idea to validate all of these documents against the revised schema with a reliable XML parser like e.g. the Xerces-J XML parser. Also, if you like, you can check by validating some of our current "real-life" mock xml documents that we have been using for client development ([source:DASISH/t5.6/client/trunk/chrome/markingcollection/content/markingcollection/annotator-service/test/mockjax/mocks]). |
| | 542 | |
| | 543 | |
| | 544 | == Cached Representation BLOB == |
| | 545 | |
| | 546 | For the back-end (and the database!): the cached representation for now is stored in the database as a BLOB. See: http://dba.stackexchange.com/questions/803/blobs-or-references-in-postgresql/815#815. |
| 679 | | == Version == |
| 680 | | |
| 681 | | MISSING in the schema: attribute URI (corresponding to the external_id in the DB) is absent. Therefore it does not appear |
| 682 | | in the JAXB-generated class "Version" and the java class has one attribute less than the DB table "version" |
| 683 | | |
| 684 | | {{{ |
| 685 | | CREATE TABLE version ( |
| 686 | | version_id SERIAL UNIQUE NOT NULL, |
| 687 | | external_id UUID UNIQUE NOT NULL, |
| 688 | | version text, |
| 689 | | ); |
| 690 | | }}} |
| 691 | | |
| 692 | | For now I'm using attrribute "version:String" now to keep "external_id/URI" in the java |
| 693 | | class "Version". |
| 694 | | |
| 695 | | === Resolution === |
| 696 | | |
| 697 | | Fix the schema: URI must be added to the version-type. The ticket: https://trac.clarin.eu/ticket/367 |
| 698 | | |
| 699 | | == LISTS of Resources, like "PermissionS" and "CachedRepresentationS", |
| 700 | | and version-siblingS connected to a particular source |
| 701 | | cannot be standalone tables in the relational DB == |
| 702 | | |
| 703 | | According to the schema: a list of Cached representations is declared as a standalone resource |
| 704 | | of type "CachedRepresentations". Every version referres to its own list of cached representations. |
| 705 | | Every such list has it own ID. |
| 706 | | |
| 707 | | According to the Rel. database: it looks a bit strange to have such lists. Instead, i have made |
| 708 | | a common joint table (verson_id, cached_representation_id). A pair (a, b) is listed in this table iff |
| 709 | | the version with the internal id "a" has cahced representation with intrenal id "b". |
| 710 | | |
| 711 | | === Resolution === |
| 712 | | |
| 713 | | Fix the schema: all lists of resources are artifacts, they do not have URI's. Ticket: https://trac.clarin.eu/ticket/368 |
| 714 | | [[BR]][[BR]] |
| 715 | | ''Stephanie:'' When removing the URI attribute for lists of resources, please make sure that the integrity of the references is still guaranteed. |
| 716 | | |
| 717 | | ''Olha'': lists are not stored in the DB but generated by the backend on the fly when they are needed. For instance, once the client wants to GET an annotation (whose schema contains the list of source-infos), the backend looks up the joint table "annotations_resources" and the table "source" and generates a list of resources for the annotation. |
| | 557 | |
