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Difference between revisions of "SMILA/Documentation/TikaPipelet"

(Configuring the Property Mapping)
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The resulting attribute is
 
* a single <tt>Value</tt>, if only one value has been extracted and the value is not appended to previously existing values
 
* a <tt>AnySeq</tt> containing all values, if more than one value has been extracted or new values are appended to existing values.
 
  
 
==== Example ====
 
==== Example ====

Revision as of 05:12, 10 January 2013

This pipelet is not yet available in our repository. We are currently in the process of creating CQs for required third party components and hopefully get permission to use it in our project.

Bundle: org.eclipse.smila.tika

Description

The TikaPipelet converts various document formats (such as PDF, Microsoft Office formats, OpenOffice formats, etc.) to plain text using Tika technology: A binary attachment content can thus be converted to plain text and stored in an attribute. In addition to that, metadata properties of the document (like title, author, etc) can be extracted and written to record attibutes. To improve the Tika parsing process it is possible to optionally pass the content-type and filename of the document stored in other Record attributes via parameters contentTypeAttribute and fileNameAttribute.

The TikaPipelet supports the configurable error handling as described in SMILA/Development_Guidelines/How_to_write_a_Pipelet#Implementation. When used in jobmanager workflows, records causing errors are dropped.

Supported document types

By default, SMILA contains only a subset of Tika that supports the conversion of:

  • plain text documents
  • HTML/XML documents
  • RTF documents
  • Microsoft Office documents
  • OpenOffice documents (OpenDocument formats)

See below on hints how to add Tika extractors for further formats

Configuration

Property Type Read Type Required Description
inputType String : ATTACHMENT, ATTRIBUTE runtime yes selects if the input is found in an attachment or attribute of the record. Usually it doesn't make sense to use "ATTRIBUTE" here because the documents to convert are binary content.
outputType String : ATTACHMENT, ATTRIBUTE runtime yes selects if output should be stored in an attachment or attribute of the record
inputName String runtime yes name of input attachment or path to input attribute (process a String literal of attribute)
outputName String runtime yes name of output attachment or path to output attribute for plain text (store result as String literal of attribute)
extractProperties String runtime no Specifies which metadata properties reported by Tika for the document should be written to which record attribute. See below for details.
contentTypeAttribute String runtime no Parameter referencing the attribute that contains the content-type of the document. If specified the content-type is used to better guide the Tika parsing process.
fileNameAttribute String runtime no Parameter referencing the attribute that contains the name of the file that was the source of the attachment content. If specified the filename is used to better guide the Tika parsing process.
exportAsHtml Boolean runtime no Flag that specifies if the output should be in HTML format (true) or not (false). Plain text output (false) is default.
pageBreak Boolean runtime no Flag that specifies if pageBreaks should be used to split the content into multiple output records (true) or not (false). This parameter is only interpreted if exportAsHtml is true Default is (false).
keepHyphens Boolean runtime no If set to "false", hyphens are removed from words at line breaks so that the separated syllables are contracted to one word (“charac-<newline>teristics” gets "characteristics"). If set to "true", this dehyphenation is disabled. Default is (false).
maxLength Long runtime no The maximum number of characters to extract. If a document contains more characters than specified all remaining characters are omitted. To get all available characters just omit this Parameter. This may lead to OutOfMemory Exceptions with big documents. Default is -1 (unlimited)

Configuring the Property Mapping

In addition to the plain text content, Tika can extract metadata properties from documents like title, author, publisher, dates of publication etc, ... The names of these properties depend very much on the documents and what is actually extracted. Some well known names like Dublin Core (dc, dcterms) are used. For a complete list please refer to the Tika documentation. To check with your documents you can download Tika and use the Tika Application to see all extracted metadata.

To store such metadata properties in SMILA records, you must specify the names of the properties you want to store in the extractProperties parameter. Usually this parameter contains a sequence of maps. The map values have the following format:

Property Type Read Type Required Description
metadataName String runtime yes The name of the metadata property
targetAttribute String runtime yes The name of Record attribute to store metadata value(s) in
singleResult Boolean runtime no Flag that specifies if only the first value (if multiple values exists) is used in the result (true) or if all values are used (false). Default is false.

Example

The following example shows how to configure the pipelet to extract the text from the attachment called Content and stores the extracted text in the attribute Text. Additionally the eventually contained metadata properties Company, Author and Title will be stored in properties.

E.g. if a word document with the value "ACME" as company and "John Doe" as creator, the resulting record would contain the plain text in the attribute Text, the value ACME in the attribute Company, as well as the value John Doe in an attribute Creator.

<proc:configuration>
  <rec:Val key="inputName">Content</rec:Val>
  <rec:Val key="inputType">ATTACHMENT</rec:Val>
  <rec:Val key="outputName">Text</rec:Val>
  <rec:Val key="outputType">ATTRIBUTE</rec:Val>
  <rec:Val key="contentTypeAttribute">MimeType</rec:Val>
  <rec:Val key="fileNameAttribute">FileName</rec:Val>
  <rec:Val key="exportAsHtml">false</rec:Val>
  <rec:Val key="pageBreak">falsec</rec:Val>
  <rec:Val key="keepHyphens">false</rec:Val>
  <rec:Val key="maxLength">100000</rec:Val>
  <rec:Seq key="extractProperties">					    
     <rec:Map>					    
        <rec:Val key="metadataName">company</rec:Val>
        <rec:Val key="targetAttribute">Company</rec:Val>			    					    
        <rec:Val key="singleResult">false</rec:Val>			    					    
     </rec:Map>
     <rec:Map>					    
        <rec:Val key="metadataName">author</rec:Val>
        <rec:Val key="targetAttribute">Author</rec:Val>			    					    
        <rec:Val key="singleResult">false</rec:Val>			    					    
     </rec:Map>
     <rec:Map>					    
        <rec:Val key="metadataName">title</rec:Val>
        <rec:Val key="targetAttribute">Title</rec:Val>			    					    
        <rec:Val key="singleResult">true</rec:Val>			    					    
     </rec:Map>		
  </rec:Seq>
</proc:configuration>


Typical Property-Names

  • Generic
    • "contributor"
    • "coverage"
    • "creator"
    • "description"
    • "format"
    • "identifier"
    • "language"
    • "modified"
    • "publisher"
    • "relation"
    • "rights"
    • "source"
    • "subject"
    • "title"
    • "type"
  • MS- Office
    • "Application-Name"
    • "Application-Version"
    • "Author"
    • "Category"
    • "Comments"
    • "Company"
    • "Content-Status"
    • "Edit-Time"
    • "Keywords"
    • "Last-Author"
    • "Manager"
    • "Notes"
    • "Presentation-Format"
    • "Revision-Number"
    • "Security"
    • "Template"
    • "Total-Time"
    • "custom:"
    • "Version"


Extending Tika

SMILA does not contain the complete Tika distribution, because some converters need third party libraries with problematic licenses that we are not allowed to distribute. However, it should be easy to include those parts of Tika into your SMILA installation yourself:

TODO