Zig Requires Chilkat v11.7.0+

PDF Footnotes in Markdown: Inline, at the End, or Dropped

See more PDF Text Extraction Examples

Demonstrates the "footnotes" option of the "markdown" operation. Small-print notes at the foot of a page are kept where they are ("inline", the default), gathered at the end of the document ("end"), or left out ("none"). Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

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

    // The two-page PDF used in this example is available at footnotes.pdf

    const pdf = try chilkat.Pdf.init();
    defer pdf.deinit();
    pdf.loadFile("qa_data/pdf/footnotes.pdf") catch {
        std.debug.print("{s}\n", .{try pdf.getLastErrorText(alloc)});
        return;
    };

    const json = try chilkat.JsonObject.init();
    defer json.deinit();
    const json_out = try chilkat.JsonObject.init();
    defer json_out.deinit();

    // Page 1 has two superscript references in the text and the two notes in small print at its foot;
    // page 2 has a third.
    pdf.extractText("markdown", json, json_out) catch {
        std.debug.print("{s}\n", .{try pdf.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("---- footnotes: inline (default) ----\n", .{});
    std.debug.print("{s}\n", .{try json_out.stringOf(alloc, "markdown")});

    json.updateString("footnotes", "end") catch {};
    pdf.extractText("markdown", json, json_out) catch {
        std.debug.print("{s}\n", .{try pdf.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("---- footnotes: end ----\n", .{});
    std.debug.print("{s}\n", .{try json_out.stringOf(alloc, "markdown")});

    json.updateString("footnotes", "none") catch {};
    pdf.extractText("markdown", json, json_out) catch {
        std.debug.print("{s}\n", .{try pdf.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("---- footnotes: none ----\n", .{});
    std.debug.print("{s}\n", .{try json_out.stringOf(alloc, "markdown")});

    // Sample output:

    // ---- footnotes: inline (default) ----
    // <!-- page 1 -->
    //
    // # The Lens on Loan
    //
    // The society located a fourth-order lens of the correct period at a museum1 in the next county, and an agreement to loan it for ten years was signed in November.2 The lens will be lit with a low-wattage electric lamp rather than oil, and it will be displayed as a historic light rather than registered as an aid to navigation.
    //
    // 1 The county maritime museum, which holds three lenses from decommissioned lights. 2 The loan is renewable and carries no fee; the society insures the lens.
    //
    // <!-- page 2 -->
    //
    // # Public Access
    //
    // The grounds opened to visitors on weekends from July. Nearly three thousand people climbed the tower over the summer,3 with no incidents.
    //
    // 3 Counted at the entrance by the volunteers on duty.
    //
    // ---- footnotes: end ----
    // <!-- page 1 -->
    //
    // # The Lens on Loan
    //
    // The society located a fourth-order lens of the correct period at a museum1 in the next county, and an agreement to loan it for ten years was signed in November.2 The lens will be lit with a low-wattage electric lamp rather than oil, and it will be displayed as a historic light rather than registered as an aid to navigation.
    //
    // <!-- page 2 -->
    //
    // # Public Access
    //
    // The grounds opened to visitors on weekends from July. Nearly three thousand people climbed the tower over the summer,3 with no incidents.
    //
    // 1 The county maritime museum, which holds three lenses from decommissioned lights. 2 The loan is renewable and carries no fee; the society insures the lens.
    //
    // 3 Counted at the entrance by the volunteers on duty.
    //
    // ---- footnotes: none ----
    // <!-- page 1 -->
    //
    // # The Lens on Loan
    //
    // The society located a fourth-order lens of the correct period at a museum1 in the next county, and an agreement to loan it for ten years was signed in November.2 The lens will be lit with a low-wattage electric lamp rather than oil, and it will be displayed as a historic light rather than registered as an aid to navigation.
    //
    // <!-- page 2 -->
    //
    // # Public Access
    //
    // The grounds opened to visitors on weekends from July. Nearly three thousand people climbed the tower over the summer,3 with no incidents.
}