PureBasic Requires Chilkat v11.7.0+

Check a PDF Text Replacement Before Applying It

See more PDF Text Replacement Examples

Demonstrates the "check" operation, which finds every placeholder and label and applies the font rule but changes nothing, and how to read its report: "ok" says whether "apply" would succeed, "replacements" lists what would be replaced, and "problems" lists what prevents it, each with a reason. Here the first check fails because a placeholder on the page was given no value; the value is added and the check passes, and only then is "apply" called. 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 is available at invoice_template.pdf

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

    success = CkPdf::ckLoadFile(pdf,"qa_data/pdf/invoice_template.pdf")
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf)
        CkPdf::ckDispose(pdf)
        ProcedureReturn
    EndIf

    ;  Values for most of the template's placeholders -- but not {{po}}, {{qty2}}, {{desc2}}, {{price2}} or {{amount2}}.
    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::ckUpdateString(json,"placeholders.customer","Acme Corp")
    CkJsonObject::ckUpdateString(json,"placeholders.date","2026-10-18")
    CkJsonObject::ckUpdateString(json,"placeholders.qty1","2")
    CkJsonObject::ckUpdateString(json,"placeholders.desc1","Cordless drill, 18 V")
    CkJsonObject::ckUpdateString(json,"placeholders.price1","$460.00")
    CkJsonObject::ckUpdateString(json,"placeholders.amount1","$920.00")
    CkJsonObject::ckUpdateString(json,"placeholders.subtotal","$920.00")
    CkJsonObject::ckUpdateString(json,"placeholders.taxRate","7.35%")
    CkJsonObject::ckUpdateString(json,"placeholders.tax","$67.62")
    CkJsonObject::ckUpdateString(json,"placeholders.total","$987.62")

    ;  "check" reports what "apply" would do, without changing the PDF.
    jsonOut.i = CkJsonObject::ckCreate()
    If jsonOut.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

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

    Debug "ok: " + Str(CkJsonObject::ckBoolOf(jsonOut,"ok"))
    Debug "would replace: " + Str(CkJsonObject::ckSizeOfArray(jsonOut,"replacements")) + " placeholders"

    ;  Each problem names the placeholder (field) or label, and a reason:
    ;    notFound - the placeholder or label is not on the selected pages
    ;    unusedPlaceholder - a placeholder on the page was given no value
    ;    missingGlyph, notInEncoding, nonStandardUnembeddedFont, unsupportedFont - the font rule
    ;    placeholderSpansFonts - the text is drawn with more than one font or size
    i.i = 0
    count_i.i = CkJsonObject::ckSizeOfArray(jsonOut,"problems")
    While i < count_i
        CkJsonObject::setCkI(jsonOut, i)
        Debug "problem: " + CkJsonObject::ckStringOf(jsonOut,"problems[i].field") + CkJsonObject::ckStringOf(jsonOut,"problems[i].label") + " - " + CkJsonObject::ckStringOf(jsonOut,"problems[i].reason") + " (page " + Str(CkJsonObject::ckIntOf(jsonOut,"problems[i].page")) + ")"
        i = i + 1
    Wend

    ;  Give the missing placeholders their values and check again.
    CkJsonObject::ckUpdateString(json,"placeholders.po","PO-88213")
    CkJsonObject::ckUpdateString(json,"placeholders.qty2","0")
    CkJsonObject::ckUpdateString(json,"placeholders.desc2","(no second item)")
    CkJsonObject::ckUpdateString(json,"placeholders.price2","")
    CkJsonObject::ckUpdateString(json,"placeholders.amount2","")
    success = CkPdf::ckTextReplace(pdf,"check",json,jsonOut)
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf)
        CkPdf::ckDispose(pdf)
        CkJsonObject::ckDispose(json)
        CkJsonObject::ckDispose(jsonOut)
        ProcedureReturn
    EndIf

    Debug "ok after adding the values: " + Str(CkJsonObject::ckBoolOf(jsonOut,"ok"))

    ;  Now apply.
    If CkJsonObject::ckBoolOf(jsonOut,"ok") = 1
        success = CkPdf::ckTextReplace(pdf,"apply",json,jsonOut)
        If success = 0
            Debug CkPdf::ckLastErrorText(pdf)
            CkPdf::ckDispose(pdf)
            CkJsonObject::ckDispose(json)
            CkJsonObject::ckDispose(jsonOut)
            ProcedureReturn
        EndIf

        Debug "applied: " + Str(CkJsonObject::ckBoolOf(jsonOut,"applied"))
        success = CkPdf::ckWriteFile(pdf,"qa_output/invoice_checked.pdf")
        If success = 0
            Debug CkPdf::ckLastErrorText(pdf)
            CkPdf::ckDispose(pdf)
            CkJsonObject::ckDispose(json)
            CkJsonObject::ckDispose(jsonOut)
            ProcedureReturn
        EndIf

    EndIf

    ;  Sample output:

    ;  ok: false
    ;  would replace: 10 placeholders
    ;  problem: po - unusedPlaceholder (page 1)
    ;  problem: qty2 - unusedPlaceholder (page 1)
    ;  problem: desc2 - unusedPlaceholder (page 1)
    ;  problem: price2 - unusedPlaceholder (page 1)
    ;  problem: amount2 - unusedPlaceholder (page 1)
    ;  ok after adding the values: true
    ;  applied: true


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


    ProcedureReturn
EndProcedure