Swift

PDF Signature Appearance Text Substitution Keywords

See more PDF Signatures Examples

This example demonstrates the text substitution keywords that can be used in the PDF signature's appearance text.

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

Swift

func chilkatTest() {
    var success: Bool = false

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

    let pdf = CkoPdf()!

    // Load a PDF to be signed.
    success = pdf.loadFile(filePath: "qa_data/pdf/empty.pdf")
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    // Options for signing are specified in JSON.
    let json = CkoJsonObject()!

    // In most cases, the signingCertificateV2 and signingTime attributes are required.
    json.updateInt(jsonPath: "signingCertificateV2", value: 1)
    json.updateInt(jsonPath: "signingTime", value: 1)

    // Put the signature on page 1, top left
    json.updateInt(jsonPath: "page", value: 1)
    json.updateString(jsonPath: "appearance.y", value: "top")
    json.updateString(jsonPath: "appearance.x", value: "left")

    // Use a font scale of 7.0
    json.updateString(jsonPath: "appearance.fontScale", value: "7.0")

    // The appearance of the PDF signature can contain any number of text lines.
    // Chilkat has defined a number of special keywords that can be used in any text line.
    // Each keyword is replaced with the actual value.
    // For example, "cert_cn" is replaced with the certificate subject's common name (CN).

    // Here we are creating a signature with many lines of text, to demonstrate each
    // keyword.
    json.updateString(jsonPath: "appearance.text[0]", value: "Date/time in PDF format: current_dt")
    json.updateString(jsonPath: "appearance.text[1]", value: "Current Local date/time: current_datetime")
    json.updateString(jsonPath: "appearance.text[2]", value: "GMT Timestamp: current_timestamp_gmt")
    json.updateString(jsonPath: "appearance.text[3]", value: "Local Timestamp: current_timestamp_local")
    json.updateString(jsonPath: "appearance.text[4]", value: "GMT RFC822 date/time: current_rfc822_dt_gmt")
    json.updateString(jsonPath: "appearance.text[5]", value: "Local RFC822 date/time: current_rfc822_dt_local")
    json.updateString(jsonPath: "appearance.text[6]", value: "Cert DN (Distinguished Name): cert_dn")
    json.updateString(jsonPath: "appearance.text[7]", value: "Cert Common Name: cert_cn")
    json.updateString(jsonPath: "appearance.text[8]", value: "Cert Organizational ID (2.5.4.97): cert_org_id")
    json.updateString(jsonPath: "appearance.text[9]", value: "Cert Email: cert_email")
    json.updateString(jsonPath: "appearance.text[10]", value: "Cert Organization: cert_organization")
    json.updateString(jsonPath: "appearance.text[11]", value: "Cert Organziational Unit: cert_ou")
    json.updateString(jsonPath: "appearance.text[12]", value: "Cert State: cert_state")
    json.updateString(jsonPath: "appearance.text[13]", value: "Cert Country: cert_country")
    json.updateString(jsonPath: "appearance.text[14]", value: "Cert Locality: cert_locality")
    json.updateString(jsonPath: "appearance.text[15]", value: "Cert Serial Number (hex): cert_serial_hex")
    json.updateString(jsonPath: "appearance.text[16]", value: "Cert Serial Number (decimal): cert_serial_dec")
    json.updateString(jsonPath: "appearance.text[17]", value: "Cert Thumbprint: cert_thumbprint")
    json.updateString(jsonPath: "appearance.text[18]", value: "Cert Issuer Common Name: cert_issuer_cn")

    let jpgData = CkoBinData()!
    success = jpgData.loadFile(path: "qa_data/jpg/seal1.jpg")
    if success == false {
        print("Failed to load the JPG image.")
        return
    }

    success = pdf.setSignatureJpeg(jpgData: jpgData)
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    // Specify that we want to display the JPG image in the center with 33% opacity.
    json.updateString(jsonPath: "appearance.image", value: "custom-jpg")
    json.updateString(jsonPath: "appearance.imagePlacement", value: "center")
    json.updateString(jsonPath: "appearance.imageOpacity", value: "33")

    // Load the signing certificate. (Use your own certificate.)
    let cert = CkoCert()!
    success = cert.loadPfxFile(path: "qa_data/pfx/myPdfSigningCert.pfx", password: "pfx_password")
    if success == false {
        print("\(cert.lastErrorText!)")
        return
    }

    // Tell the pdf object to use the certificate for signing.
    success = pdf.setSigningCert(cert: cert)
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    success = pdf.sign(jsonOptions: json, outFilePath: "qa_output/hello_signed.pdf")
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    print("The PDF has been successfully cryptographically signed.")

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

    // (image:https://example-code.com/images/pdf_signature_text_replacements.jpg/endImage)

}