Unicode C Requires Chilkat v11.7.0+

Get a PDF Field Value by its Label (Value to the Right)

See more PDF Text Extraction Examples

Demonstrates the "label" option, which captures the text that belongs to a caption such as "Invoice Number:" without needing coordinates. With labelValue "right", the value is the rest of the label's line. Label matching ignores case, extra spaces and a trailing colon. Unicode C

#include <C_CkPdfW.h>
#include <C_CkJsonObjectW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPdfW pdf;
    HCkJsonObjectW json;
    HCkJsonObjectW jsonOut;

    success = FALSE;

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

    //  The invoice used in this example is available at invoice_labels.pdf

    pdf = CkPdfW_Create();
    success = CkPdfW_LoadFile(pdf,L"qa_data/pdf/invoice_labels.pdf");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        return;
    }

    json = CkJsonObjectW_Create();
    jsonOut = CkJsonObjectW_Create();

    //  The invoice has lines such as "Invoice Number:   INV-2026-0412".
    //  The label option restricts the "text" operation to the text belonging to the label.
    CkJsonObjectW_UpdateString(json,L"label",L"Invoice Number");

    //  "right" means the value is the rest of the label's line.
    //  (The default, "auto", uses the rest of the line if there is text there, otherwise the block below.)
    CkJsonObjectW_UpdateString(json,L"labelValue",L"right");

    success = CkPdfW_ExtractText(pdf,L"text",json,jsonOut);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        CkJsonObjectW_Dispose(json);
        CkJsonObjectW_Dispose(jsonOut);
        return;
    }

    //  The value is returned as the text.
    wprintf(L"Invoice Number: %s\n",CkJsonObjectW_stringOf(jsonOut,L"text"));

    //  The labelMatches array tells where the label was found and how it appeared in the PDF.
    wprintf(L"Found on page %d as \"%s\"\n",CkJsonObjectW_IntOf(jsonOut,L"labelMatches[0].page"),CkJsonObjectW_stringOf(jsonOut,L"labelMatches[0].label"));

    //  Matching ignores case and the trailing colon, so these all work:
    CkJsonObjectW_UpdateString(json,L"label",L"CUSTOMER:");
    success = CkPdfW_ExtractText(pdf,L"text",json,jsonOut);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        CkJsonObjectW_Dispose(json);
        CkJsonObjectW_Dispose(jsonOut);
        return;
    }

    wprintf(L"Customer: %s\n",CkJsonObjectW_stringOf(jsonOut,L"text"));

    CkJsonObjectW_UpdateString(json,L"label",L"due date");
    success = CkPdfW_ExtractText(pdf,L"text",json,jsonOut);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        CkJsonObjectW_Dispose(json);
        CkJsonObjectW_Dispose(jsonOut);
        return;
    }

    wprintf(L"Due Date: %s\n",CkJsonObjectW_stringOf(jsonOut,L"text"));

    //  The totals at the foot of the invoice are right-aligned labels with the amount beside them.
    CkJsonObjectW_UpdateString(json,L"label",L"Total Due");
    success = CkPdfW_ExtractText(pdf,L"text",json,jsonOut);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        CkJsonObjectW_Dispose(json);
        CkJsonObjectW_Dispose(jsonOut);
        return;
    }

    wprintf(L"Total Due: %s\n",CkJsonObjectW_stringOf(jsonOut,L"text"));

    //  A label that is not found is not an error.  The text is empty, labelMatches is empty,
    //  and the quality report has an issue with the code "labelNotFound".
    CkJsonObjectW_UpdateString(json,L"label",L"Tracking Number");
    success = CkPdfW_ExtractText(pdf,L"text",json,jsonOut);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        CkJsonObjectW_Dispose(json);
        CkJsonObjectW_Dispose(jsonOut);
        return;
    }

    if (CkJsonObjectW_SizeOfArray(jsonOut,L"labelMatches") == 0) {
        wprintf(L"Tracking Number: (not found) %s\n",CkJsonObjectW_stringOf(jsonOut,L"quality.pages[0].issues[0].code"));
    }

    //  Sample output:

    //  Invoice Number: INV-2026-0412
    //  Found on page 1 as "Invoice Number:"
    //  Customer: Northwind Traders
    //  Due Date: April 13, 2026
    //  Total Due: $1,234.53
    //  Tracking Number: (not found) labelNotFound


    CkPdfW_Dispose(pdf);
    CkJsonObjectW_Dispose(json);
    CkJsonObjectW_Dispose(jsonOut);

    }