Package org.corpus_tools.pepper.modules

Interface PepperExporter

  • All Superinterfaces:
    PepperModule
    All Known Implementing Classes:
    DoNothingExporter, DOTExporter, PepperExporterImpl, SaltXMLExporter, TextExporter
    public interface PepperExporter
extends PepperModule

    A mapping task in the Pepper workflow is not a monolithic block. It consists of several smaller steps.

    • Declare the fingerprint of the module. This is part of the constructor.
    • Check readyness of the module.
    • Export the corpus structure.
    • Export the document structure and create a mapper for each corpus and document.
    • clean-up
    The following describes the single steps in short. To get a more detailed explanation, take a look to the documentations found at http://u.hu-berlin.de/ saltnpepper.

    Declare the fingerprint

    Initialize the module and set the modules name, its description and the format description of data which are importable. This is part of the constructor: 
     public MyModule() {
        super("Name of the module");
        setSupplierContact(URI.createURI("Contact address of the module's supplier"));
        setSupplierHomepage(URI.createURI("homepage of the module"));
        setDesc("A short description of what is the intention of this module, for instance which formats are importable. ");
        this.addSupportedFormat("The name of a format which is importable e.g. txt",
                        "The version corresponding to the format name", null);
 }

    Check readyness of the module

    This method is invoked by the Pepper framework before the mapping process is started. This method must return true, otherwise, this Pepper module could not be used in a Pepper workflow. At this point problems which prevent the module from being used you can report all problems to the user, for instance a database connection could not be established. 
     public boolean isReadyToStart() {
        return (true);
 }

    Export corpus structure

    The corpus-structure export is handled in the method exportCorpusStructure(). It is invoked on top of the method ' start() ' of the PepperExporter . For totally changing the default behavior just override this method. The aim of the method exportCorpusStructure() is to fill the map of corresponding corpus-structure and file structure. The file structure is automatically created, there are just URI s pointing to the virtual file or folder. The creation of the file or folder has to be done by the Pepper module itself in method PepperMapper.mapSCorpus() or PepperMapper.mapSDocument(). To adapt the creation of this 'virtual' file structure, you first have to choose the mode of export. You can do this for instance in method 'readyToStart()', as shown in the following snippet. But even in the constructor as well. 
     public boolean isReadyToStart(){ 
        ... //option 1
        setExportMode(EXPORT_MODE.NO_EXPORT); 
        //option 2
        setExportMode(EXPORT_MODE.CORPORA_ONLY); 
        //option 3
        setExportMode(EXPORT_MODE.DOCUMENTS_IN_FILES);
  //sets the ending, which should be added to the documents name
        setDocumentEnding(ENDING_TAB); 
        .. 
 }
    In this snippet, option 1 means that nothing will be mapped. Option 2 means that only SCorpus objects are mapped to a folder and SDocument objects will be ignored. And option 3 means that SCorpus objects are mapped to a folder and SDocument objects are mapped to a file. The ending of that file can be determined by passing the ending with method setDocumentEnding(String). In the given snippet a URI having the ending 'tab' is created for each SDocument.

    Export the document structure

    In the method PepperModule.createPepperMapper(Identifier) a PepperMapper object needs to be initialized and returned. The PepperMapper is the major part major part doing the mapping. It provides the methods PepperMapper.mapSCorpus() to handle the mapping of a single SCorpus object and PepperMapper.mapSDocument() to handle a single SDocument object. Both methods are invoked by the Pepper framework. To set the PepperMapper.getResourceURI(), which offers the mapper the file or folder of the current SCorpus or SDocument object, this filed needs to be set in the PepperModule.createPepperMapper(Identifier) method. The following snippet shows a dummy of that method: 
     public PepperMapper createPepperMapper(Identifier sElementId) {
        PepperMapper mapper = new PepperMapperImpl() {
                @Override
                public DOCUMENT_STATUS mapSCorpus() {
                        // handling the mapping of a single corpus
 
                        // accessing the current file or folder
                        getResourceURI();
 
                        // returning, that the corpus was mapped successfully
                        return (DOCUMENT_STATUS.COMPLETED);
                }
 
                @Override
                public DOCUMENT_STATUS mapSDocument() {
                        // handling the mapping of a single document
 
                        // accessing the current file or folder
                        getResourceURI();
 
                        // returning, that the document was mapped successfully
                        return (DOCUMENT_STATUS.COMPLETED);
                }
        };
        // pass current file or folder to mapper. When using
        // PepperImporter.importCorpusStructure or
        // PepperExporter.exportCorpusStructure, the mapping between file or
        // folder
        // and SCorpus or SDocument was stored here
        mapper.setResourceURI(getIdentifier2ResourceTable().get(sElementId));
        return (mapper);
 }

    clean-up

    Sometimes it might be necessary to clean up after the module did the job. For instance when writing an im- or an exporter it might be necessary to close file streams, a db connection etc. Therefore, after the processing is done, the Pepper framework calls the method described in the following snippet: 
     public void end() {
        super.end();
        // do some clean up like closing of streams etc.
 }

    Author:
    Florian Zipser

    • Method Detail

      • getSupportedFormats

        List<FormatDesc> getSupportedFormats()
        TODO docu
        Returns:

      • getCorpusDesc

        CorpusDesc getCorpusDesc()
        TODO docu
        Returns:

      • getDocumentEnding

        String getDocumentEnding()
        Returns the format ending for files to be exported and related to SDocument objects.
        Returns:
        file ending for SDocument objects to be exported.

      • setDocumentEnding

        void setDocumentEnding​(String sDocumentEnding)
        Sets the format ending for files to be exported and related to SDocument objects.
        Parameters:
        file - ending for SDocument objects to be exported.

      • setCorpusDesc

        void setCorpusDesc​(CorpusDesc corpusDesc)
        TODO docu

      • getIdentifier2ResourceTable

        Map<org.corpus_tools.salt.graph.Identifier,​org.eclipse.emf.common.util.URI> getIdentifier2ResourceTable()
        Returns table correspondence between Identifier and a resource. Stores Identifier objects corresponding to either a SDocument or a SCorpus object, which has been created during the run of #importCorpusStructure(SCorpusGraph). Corresponding to the Identifier object this table stores the resource from where the element shall be imported.
        For instance:
        corpus_1 /home/me/corpora/myCorpus
        corpus_2 /home/me/corpora/myCorpus/subcorpus
        doc_1 /home/me/corpora/myCorpus/subcorpus/document1.xml
        doc_2 /home/me/corpora/myCorpus/subcorpus/document2.xml
        Returns:
        table correspondence between Identifier and a resource.

      • createFolderStructure

        org.eclipse.emf.common.util.URI createFolderStructure​(org.corpus_tools.salt.graph.Identifier sElementId)
        Creates a folder structure basing on the passed corpus path in ( CorpusDesc.getCorpusPath()). For each segment in Identifier a folder is created.
        Returns:
        the entire path of Identifier as file path, which was created on disk

      • setExportMode

        void setExportMode​(PepperExporter.EXPORT_MODE exportMode)
        Determines how the corpus-structure should be exported.
        • EXPORT_MODE#NO_EXPORT - corpus-structure should not be exported
        • EXPORT_MODE#CORPORA_ONLY SCorpus objects are exported into a folder structure, but SDocument objects are not exported
        • EXPORT_MODE#DOCUMENTS_IN_FILES - SCorpus objects are exported into a folder structure and SDocument objects are stored in files having the ending determined by PepperExporter#getDocumentEnding()
        Parameters:
        exportMode -

      • exportCorpusStructure

        void exportCorpusStructure()
        This method is called by PepperModule.start() to export the corpus-structure into a folder-structure. That means, each Identifier belonging to a SDocument or SCorpus object is stored getIdentifier2ResourceTable() together with thze corresponding file-structure object (file or folder) located by a URI. The URI object corresponding to files will get the file ending determined by #getDocumentEnding(String), which could be set by setDocumentEnding(String).
        To adapt the creation of URIs set the export mode via setExportMode(EXPORT_MODE).

      • addSupportedFormat

        FormatDesc addSupportedFormat​(String formatName,
                              String formatVersion,
                              org.eclipse.emf.common.util.URI formatReference)
        {@inheritDoc PepperModuleDesc#addSupportedFormat(String, String, URI)}