Zig

PayPal - Generate Invoice Number

See more PayPal Examples

Generates the next invoice number that is available to the user.

Note: This example requires Chilkat v9.5.0.65 or greater.

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 v9.5.0.65 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..
    // ----------------------------------------------------------------------------------------------

    // Clear the REST object of any headers or query params from previous requests.
    rest.clearAllHeaders() catch {};
    rest.clearAllQueryParams() catch {};

    rest.addHeader("Authorization", try sb_auth.getAsString(alloc)) catch {};

    // Send the POST request with an emtpy body and get the JSON response.
    const sb_json_request = try chilkat.StringBuilder.init();
    defer sb_json_request.deinit();
    const sb_json_response = try chilkat.StringBuilder.init();
    defer sb_json_response.deinit();
    rest.fullRequestSb("POST", "/v1/invoicing/invoices/next-invoice-number", sb_json_request, 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;
    }

    // Sample JSON response is shown below.
    std.debug.print("{s}\n", .{try json.emit(alloc)});
    std.debug.print("----------------------\n", .{});
    std.debug.print("Next invoice number: {s}\n", .{try json.stringOf(alloc, "number")});
    std.debug.print("success\n", .{});

    // ------------------------------------------------
    // A sample JSON response:

    //     {
    //       "number": "0003"
    //     }
}