Xojo Plugin 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. Xojo Plugin

Dim success As Boolean
success = False

//  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

Dim pdf As New Chilkat.Pdf
success = pdf.LoadFile("qa_data/pdf/invoice_template.pdf")
If (success = False) Then
    System.DebugLog(pdf.LastErrorText)
    Return
End If

//  Values for most of the template's placeholders -- but not {{po}}, {{qty2}}, {{desc2}}, {{price2}} or {{amount2}}.
Dim json As New Chilkat.JsonObject
success = json.UpdateString("placeholders.customer","Acme Corp")
success = json.UpdateString("placeholders.date","2026-10-18")
success = json.UpdateString("placeholders.qty1","2")
success = json.UpdateString("placeholders.desc1","Cordless drill, 18 V")
success = json.UpdateString("placeholders.price1","$460.00")
success = json.UpdateString("placeholders.amount1","$920.00")
success = json.UpdateString("placeholders.subtotal","$920.00")
success = json.UpdateString("placeholders.taxRate","7.35%")
success = json.UpdateString("placeholders.tax","$67.62")
success = json.UpdateString("placeholders.total","$987.62")

//  "check" reports what "apply" would do, without changing the PDF.
Dim jsonOut As New Chilkat.JsonObject
success = pdf.TextReplace("check",json,jsonOut)
If (success = False) Then
    System.DebugLog(pdf.LastErrorText)
    Return
End If

System.DebugLog("ok: " + Str(jsonOut.BoolOf("ok")))
System.DebugLog("would replace: " + Str(jsonOut.SizeOfArray("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
Dim i As Int32
i = 0
Dim count_i As Int32
count_i = jsonOut.SizeOfArray("problems")
While i < count_i
    jsonOut.I = i
    System.DebugLog("problem: " + jsonOut.StringOf("problems[i].field") + jsonOut.StringOf("problems[i].label") + " - " + jsonOut.StringOf("problems[i].reason") + " (page " _
         + Str(jsonOut.IntOf("problems[i].page")) + ")")
    i = i + 1
Wend

//  Give the missing placeholders their values and check again.
success = json.UpdateString("placeholders.po","PO-88213")
success = json.UpdateString("placeholders.qty2","0")
success = json.UpdateString("placeholders.desc2","(no second item)")
success = json.UpdateString("placeholders.price2","")
success = json.UpdateString("placeholders.amount2","")
success = pdf.TextReplace("check",json,jsonOut)
If (success = False) Then
    System.DebugLog(pdf.LastErrorText)
    Return
End If

System.DebugLog("ok after adding the values: " + Str(jsonOut.BoolOf("ok")))

//  Now apply.
If (jsonOut.BoolOf("ok") = True) Then
    success = pdf.TextReplace("apply",json,jsonOut)
    If (success = False) Then
        System.DebugLog(pdf.LastErrorText)
        Return
    End If

    System.DebugLog("applied: " + Str(jsonOut.BoolOf("applied")))
    success = pdf.WriteFile("qa_output/invoice_checked.pdf")
    If (success = False) Then
        System.DebugLog(pdf.LastErrorText)
        Return
    End If

End If

//  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