Visual FoxPro

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.

Visual FoxPro

LOCAL lnSuccess
LOCAL loPdf
LOCAL loJson
LOCAL loJpgData
LOCAL loCert

lnSuccess = 0

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

loPdf = CreateObject('Chilkat.Pdf')

* Load a PDF to be signed.
lnSuccess = loPdf.LoadFile("qa_data/pdf/empty.pdf")
IF (lnSuccess = 0) THEN
    ? loPdf.LastErrorText
    RELEASE loPdf
    CANCEL
ENDIF

* Options for signing are specified in JSON.
loJson = CreateObject('Chilkat.JsonObject')

* In most cases, the signingCertificateV2 and signingTime attributes are required.
loJson.UpdateInt("signingCertificateV2",1)
loJson.UpdateInt("signingTime",1)

* Put the signature on page 1, top left
loJson.UpdateInt("page",1)
loJson.UpdateString("appearance.y","top")
loJson.UpdateString("appearance.x","left")

* Use a font scale of 7.0
loJson.UpdateString("appearance.fontScale","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.
loJson.UpdateString("appearance.text[0]","Date/time in PDF format: current_dt")
loJson.UpdateString("appearance.text[1]","Current Local date/time: current_datetime")
loJson.UpdateString("appearance.text[2]","GMT Timestamp: current_timestamp_gmt")
loJson.UpdateString("appearance.text[3]","Local Timestamp: current_timestamp_local")
loJson.UpdateString("appearance.text[4]","GMT RFC822 date/time: current_rfc822_dt_gmt")
loJson.UpdateString("appearance.text[5]","Local RFC822 date/time: current_rfc822_dt_local")
loJson.UpdateString("appearance.text[6]","Cert DN (Distinguished Name): cert_dn")
loJson.UpdateString("appearance.text[7]","Cert Common Name: cert_cn")
loJson.UpdateString("appearance.text[8]","Cert Organizational ID (2.5.4.97): cert_org_id")
loJson.UpdateString("appearance.text[9]","Cert Email: cert_email")
loJson.UpdateString("appearance.text[10]","Cert Organization: cert_organization")
loJson.UpdateString("appearance.text[11]","Cert Organziational Unit: cert_ou")
loJson.UpdateString("appearance.text[12]","Cert State: cert_state")
loJson.UpdateString("appearance.text[13]","Cert Country: cert_country")
loJson.UpdateString("appearance.text[14]","Cert Locality: cert_locality")
loJson.UpdateString("appearance.text[15]","Cert Serial Number (hex): cert_serial_hex")
loJson.UpdateString("appearance.text[16]","Cert Serial Number (decimal): cert_serial_dec")
loJson.UpdateString("appearance.text[17]","Cert Thumbprint: cert_thumbprint")
loJson.UpdateString("appearance.text[18]","Cert Issuer Common Name: cert_issuer_cn")

loJpgData = CreateObject('Chilkat.BinData')
lnSuccess = loJpgData.LoadFile("qa_data/jpg/seal1.jpg")
IF (lnSuccess = 0) THEN
    ? "Failed to load the JPG image."
    RELEASE loPdf
    RELEASE loJson
    RELEASE loJpgData
    CANCEL
ENDIF

lnSuccess = loPdf.SetSignatureJpeg(loJpgData)
IF (lnSuccess = 0) THEN
    ? loPdf.LastErrorText
    RELEASE loPdf
    RELEASE loJson
    RELEASE loJpgData
    CANCEL
ENDIF

* Specify that we want to display the JPG image in the center with 33% opacity.
loJson.UpdateString("appearance.image","custom-jpg")
loJson.UpdateString("appearance.imagePlacement","center")
loJson.UpdateString("appearance.imageOpacity","33")

* Load the signing certificate. (Use your own certificate.)
loCert = CreateObject('Chilkat.Cert')
lnSuccess = loCert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","pfx_password")
IF (lnSuccess = 0) THEN
    ? loCert.LastErrorText
    RELEASE loPdf
    RELEASE loJson
    RELEASE loJpgData
    RELEASE loCert
    CANCEL
ENDIF

* Tell the pdf object to use the certificate for signing.
lnSuccess = loPdf.SetSigningCert(loCert)
IF (lnSuccess = 0) THEN
    ? loPdf.LastErrorText
    RELEASE loPdf
    RELEASE loJson
    RELEASE loJpgData
    RELEASE loCert
    CANCEL
ENDIF

lnSuccess = loPdf.SignPdf(loJson,"qa_output/hello_signed.pdf")
IF (lnSuccess = 0) THEN
    ? loPdf.LastErrorText
    RELEASE loPdf
    RELEASE loJson
    RELEASE loJpgData
    RELEASE loCert
    CANCEL
ENDIF

? "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)

RELEASE loPdf
RELEASE loJson
RELEASE loJpgData
RELEASE loCert