(PureBasic) PDF Signatures with Built-in SVG Graphics

See more PDF Signatures Examples

This example demonstrates the built-in SVG graphics that can be applied to the appearance when signing a PDF.

Note: This example requires Chilkat v9.5.0.85 or greater.

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

Procedure ChilkatExample()

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

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

    ; Load a PDF to be signed.
    ; The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
    success.i = CkPdf::ckLoadFile(pdf,"qa_data/pdf/hello.pdf")
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf)
        CkPdf::ckDispose(pdf)
        ProcedureReturn
    EndIf

    ; Options for signing are specified in JSON.
    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; In most cases, the signingCertificateV2 and signingTime attributes are required.
    CkJsonObject::ckUpdateInt(json,"signingCertificateV2",1)
    CkJsonObject::ckUpdateInt(json,"signingTime",1)

    ; Specify the location/position, scale, and content of the signature's appearance.
    CkJsonObject::ckUpdateInt(json,"page",1)
    CkJsonObject::ckUpdateString(json,"appearance.y","top")
    CkJsonObject::ckUpdateString(json,"appearance.x","left")
    CkJsonObject::ckUpdateString(json,"appearance.fontScale","10.0")
    CkJsonObject::ckUpdateString(json,"appearance.text[0]","Digitally signed by: cert_cn")
    CkJsonObject::ckUpdateString(json,"appearance.text[1]","current_dt")
    CkJsonObject::ckUpdateString(json,"appearance.text[2]","The crazy brown fox jumps over the lazy dog.")

    ; In addition to the above, this example adds a built-in SVG graphic to the appearance.
    ; The built-in SVG graphic is specified by a name, such as "green-check-grey-circle".
    ; The full list of graphic names and images are shown below.
    CkJsonObject::ckUpdateString(json,"appearance.image","green-check-grey-circle")

    ; The graphic can be placed "left", "center", or "right".
    ; If "center", then the graphic is displayed behind the text.
    CkJsonObject::ckUpdateString(json,"appearance.imagePlacement","left")

    ; The graphic's opacity can range from 1 to 100.
    ; Centered graphics look best with less opacity (50 or less).
    ; In this example, we'll keep the opacity at 100.
    CkJsonObject::ckUpdateString(json,"appearance.imageOpacity","100")

    ; Here's an example of the signature's appearance if we centered the SVG graphic with an opacity of 40%
    

    ; Load the signing certificate. (Use your own certificate.)
    cert.i = CkCert::ckCreate()
    If cert.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkCert::ckLoadPfxFile(cert,"qa_data/pfx/myPdfSigningCert.pfx","secret")
    If success = 0
        Debug CkCert::ckLastErrorText(cert)
        CkPdf::ckDispose(pdf)
        CkJsonObject::ckDispose(json)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    ; Tell the pdf object to use the certificate for signing.
    success = CkPdf::ckSetSigningCert(pdf,cert)
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf)
        CkPdf::ckDispose(pdf)
        CkJsonObject::ckDispose(json)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    success = CkPdf::ckSignPdf(pdf,json,"qa_output/hello_signed.pdf")
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf)
        CkPdf::ckDispose(pdf)
        CkJsonObject::ckDispose(json)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    Debug "The PDF has been successfully cryptographically signed."

    ; The appearance of the signature appears in Adobe Acrobat as shown here:

    

    ; The SVG icon graphics are embedded within the Chilkat library, 
    ; and were graciously provided by uxwing - Free SVG Icons 
    ; 
    ; The uxwing licensing terms are reproduced here and can be verified at uxwing licensing

    ; Icons from uxwing.com are free (see https://uxwing.com/license/)
    ; 	- All icons on UXWing free to download, and use personal, commercial projects.
    ; 	- Attribution and Credit is NOT required, however, any credit will be much appreciated.
    ; 	- There is no limit to the number of times you can use.
    ; 	- You may modify the resources according to your requirements.

    ; The set of SVG names and the corresponding graphics are shown below.
    ; 
    ; For example, if we specify "green-check-green-circle"
    CkJsonObject::ckUpdateString(json,"appearance.image","green-check-green-circle")
    ; We get:
    

    ; "application-approved"
    

    ; "application-rejected"
    

    ; "document-accepted"
    

    ; "approved"
    

    ; "blue-check-mark"
    

    ; "green-check-mark"
    

    ; "green-check-grey-circle"
    

    ; "red-x-red-circle"
    

    ; "rejected"
    

    ; "result-failure"
    

    ; "result-pass"
    

    ; "signature"
    

    ; "document-check"
    

    ; "document-x"
    

    ; "red-x-grey-circle"
    


    CkPdf::ckDispose(pdf)
    CkJsonObject::ckDispose(json)
    CkCert::ckDispose(cert)


    ProcedureReturn
EndProcedure