Xojo Plugin Requires Chilkat v11.7.0+

Get Every Occurrence of a Label in a PDF

See more PDF Text Extraction Examples

Demonstrates the "labelOccurrence" option. When the same label appears more than once (for example "Total:" on each of several receipts), "first" (the default) uses the first occurrence, "all" returns every occurrence with its page, and a number selects one occurrence. 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 (three receipts, one per page) is available at three_receipts.pdf

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

Dim json As New Chilkat.JsonObject
Dim jsonOut As New Chilkat.JsonObject

//  Each of the three pages is a receipt with a "Total:" line.
success = json.UpdateString("label","Total")
success = json.UpdateString("labelValue","right")

//  By default only the first occurrence (in reading order) is used.
success = pdf.ExtractText("text",json,jsonOut)
If (success = False) Then
    System.DebugLog(pdf.LastErrorText)
    Return
End If

System.DebugLog("First total: " + jsonOut.StringOf("text"))

//  labelOccurrence "all" returns every occurrence.  The "text" member holds the values joined
//  by line breaks, and labelMatches has one entry per occurrence with its page.
success = json.UpdateString("labelOccurrence","all")
success = pdf.ExtractText("text",json,jsonOut)
If (success = False) Then
    System.DebugLog(pdf.LastErrorText)
    Return
End If

Dim i As Int32
i = 0
Dim count_i As Int32
count_i = jsonOut.SizeOfArray("labelMatches")
While i < count_i
    jsonOut.I = i
    System.DebugLog("Page " + Str(jsonOut.IntOf("labelMatches[i].page")) + " total: " + jsonOut.StringOf("labelMatches[i].text"))
    i = i + 1
Wend

//  A number selects one occurrence: 2 is the second.
success = json.UpdateInt("labelOccurrence",2)
success = pdf.ExtractText("text",json,jsonOut)
If (success = False) Then
    System.DebugLog(pdf.LastErrorText)
    Return
End If

System.DebugLog("Second total: " + jsonOut.StringOf("text"))

//  The occurrences are counted over the selected pages, so combining "pages" with the label
//  is another way to pick one receipt:
success = json.UpdateString("labelOccurrence","first")
success = json.UpdateString("pages","3")
success = json.UpdateString("label","Receipt No.")
success = pdf.ExtractText("text",json,jsonOut)
If (success = False) Then
    System.DebugLog(pdf.LastErrorText)
    Return
End If

System.DebugLog("Receipt number on page 3: " + jsonOut.StringOf("text"))

//  Sample output:

//  First total: $19.86
//  Page 1 total: $19.86
//  Page 2 total: $17.34
//  Page 3 total: $23.62
//  Second total: $17.34
//  Receipt number on page 3: 1003