Zig

PayPal Generate QR Code

See more PayPal Examples

Generates a QR code for an invoice, by ID.

The QR code is a PNG image in Base64-encoded format that corresponds to the invoice ID.

Note: A QR code can only be generated for an invoice that has been both created and sent.

See also Generate QR Code

Zig

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

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

    // Note: Requires Chilkat v9.5.0.64 or greater.

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

    // Load our previously obtained access token. (see PayPal OAuth2 Access Token)
    const json_token = try chilkat.JsonObject.init();
    defer json_token.deinit();
    json_token.loadFile("qa_data/tokens/paypal.json") catch {};

    // Build the Authorization request header field value.
    const sb_auth = try chilkat.StringBuilder.init();
    defer sb_auth.deinit();
    // token_type should be "Bearer"
    sb_auth.append(try json_token.stringOf(alloc, "token_type")) catch {};
    sb_auth.append(" ") catch {};
    sb_auth.append(try json_token.stringOf(alloc, "access_token")) catch {};

    // Make the initial connection.
    // A single REST object, once connected, can be used for many PayPal REST API calls.
    // The auto-reconnect indicates that if the already-established HTTPS connection is closed,
    // then it will be automatically re-established as needed.
    const rest = try chilkat.Rest.init();
    defer rest.deinit();
    const b_auto_reconnect = true;
    rest.connect("api.sandbox.paypal.com", 443, true, b_auto_reconnect) catch {
        std.debug.print("{s}\n", .{try rest.getLastErrorText(alloc)});
        return;
    };

    // ----------------------------------------------------------------------------------------------
    // The code above this comment could be placed inside a function/subroutine within the application
    // because the connection does not need to be made for every request.  Once the connection is made
    // the app may send many requests..
    // ----------------------------------------------------------------------------------------------

    // Build a path using an invoice ID.
    const sb_path = try chilkat.StringBuilder.init();
    defer sb_path.deinit();
    sb_path.append("/v1/invoicing/invoices/invoice_id/qr-code") catch {};
    _ = sb_path.replace("invoice_id", "INV2-ZG2H-HKAW-PMWU-N6ZR");

    rest.addHeader("Authorization", try sb_auth.getAsString(alloc)) catch {};
    // A 500x500 image results in a PNG file of approx. 4K bytes in size.
    rest.addQueryParam("width", "500") catch {};
    rest.addQueryParam("height", "500") catch {};
    rest.addQueryParam("action", "pay") catch {};

    // Send the GET request and get the PNG image data as base64.
    // A successful JSON response looks like this:
    // {"image":"iVBORw0KGgoAA....AASUVORK5CYII="}
    const sb_json_response = try chilkat.StringBuilder.init();
    defer sb_json_response.deinit();
    rest.fullRequestNoBodySb("GET", try sb_path.getAsString(alloc), sb_json_response) catch {
        std.debug.print("{s}\n", .{try rest.getLastErrorText(alloc)});
        return;
    };

    const json = try chilkat.JsonObject.init();
    defer json.deinit();
    json.setEmitCompact(false);
    json.loadSb(sb_json_response) catch {};

    std.debug.print("Response Status Code = {d}\n", .{rest.getResponseStatusCode()});

    // Did we get a 200 success response?
    if (rest.getResponseStatusCode() != 200) {
        std.debug.print("{s}\n", .{try json.emit(alloc)});
        std.debug.print("Failed.\n", .{});
        return;
    }

    // If the 200 response is received, the response body contains the PNG data.
    // Save the PNG to a file.
    const png_data = try chilkat.BinData.init();
    defer png_data.deinit();
    png_data.appendEncoded(try json.stringOf(alloc, "image"), "base64") catch {};
    png_data.writeFile("qa_output/paypal_qr_code.png") catch {
        std.debug.print("Failed to save PNG file.\n", .{});
        return;
    };

    std.debug.print("Success.\n", .{});
}