PureBasic Requires Chilkat v11.7.0+

Extract Text from a PDF that Forbids Copying

See more PDF Text Extraction Examples

Demonstrates a PDF that opens without a password but whose permissions do not allow copying text. The "text", "markdown", "search" and "tables" operations fail with that reason; "assess" always works. Loading the PDF with the OwnerPassword property set grants owner rights, and extraction works. PureBasic

IncludeFile "CkPdf.pb"
IncludeFile "CkJsonObject.pb"

Procedure ChilkatExample()

    success.i = 0

    ;  This example requires the Chilkat API to have been previously unlocked.
    ;  See Global Unlock Sample for sample code.

    ;  The PDF used in this example (owner password: owner-secret; copying not permitted) is available at no_copy_permission.pdf

    pdf.i = CkPdf::ckCreate()
    If pdf.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    jsonOut.i = CkJsonObject::ckCreate()
    If jsonOut.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ;  The PDF opens without a password.
    success = CkPdf::ckLoadFile(pdf,"qa_data/pdf/no_copy_permission.pdf")
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf)
        CkPdf::ckDispose(pdf)
        CkJsonObject::ckDispose(json)
        CkJsonObject::ckDispose(jsonOut)
        ProcedureReturn
    EndIf

    ;  Extracting text is refused, because the PDF's permissions do not allow copying.
    success = CkPdf::ckExtractText(pdf,"text",json,jsonOut)
    If success = 0
        Debug "Extraction refused: " + CkPdf::ckLastErrorText(pdf)
    EndIf

    ;  "assess" reports only counts and ratings, never text, so it is always allowed.
    success = CkPdf::ckExtractText(pdf,"assess",json,jsonOut)
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf)
        CkPdf::ckDispose(pdf)
        CkJsonObject::ckDispose(json)
        CkJsonObject::ckDispose(jsonOut)
        ProcedureReturn
    EndIf

    Debug "rating: " + CkJsonObject::ckStringOf(jsonOut,"quality.rating")

    ;  Load with the owner password to get owner rights, which include copying.
    CkPdf::setCkOwnerPassword(pdf, "owner-secret")
    success = CkPdf::ckLoadFile(pdf,"qa_data/pdf/no_copy_permission.pdf")
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf)
        CkPdf::ckDispose(pdf)
        CkJsonObject::ckDispose(json)
        CkJsonObject::ckDispose(jsonOut)
        ProcedureReturn
    EndIf

    success = CkPdf::ckExtractText(pdf,"text",json,jsonOut)
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf)
        CkPdf::ckDispose(pdf)
        CkJsonObject::ckDispose(json)
        CkJsonObject::ckDispose(jsonOut)
        ProcedureReturn
    EndIf

    Debug CkJsonObject::ckStringOf(jsonOut,"text")

    ;  Sample output:

    ;  Extraction refused: ChilkatLog:
    ;    ExtractText:
    ;      ...
    ;        The PDF's permissions do not allow copying or extracting text (load it with the owner password to extract).
    ;      ...
    ;  rating: good
    ;  Visitor Leaflet
    ;  
    ;  Welcome to the harbor lighthouse. The tower is open on weekends from July to September.
    ;  
    ;  Please keep to the marked paths and do not climb on the breakwater.
    ;  
    ;  The lantern room is closed in high winds.


    CkPdf::ckDispose(pdf)
    CkJsonObject::ckDispose(json)
    CkJsonObject::ckDispose(jsonOut)


    ProcedureReturn
EndProcedure