Zig Requires Chilkat v10.1.3+

Datev OAuth2 Access Token

See more Datev Examples

Demonstrates how to get a Datev OAuth2 access token from a desktop application or script. Zig

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

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

    // To further clarify, see OAuth 2.0 Authorization Flow

    const oauth2 = try chilkat.OAuth2.init();
    defer oauth2.deinit();

    // Your Datev app should use "http://localhost" (no trailing forward slash) for the redirect URL.
    oauth2.setListenPort(3017);

    // 

    oauth2.setAuthorizationEndpoint("https://login.datev.de/openidsandbox/authorize");
    oauth2.setTokenEndpoint("https://sandbox-api.datev.de/token");

    // Replace this with your actual client ID.
    oauth2.setClientId("DATEV_CLIENT_ID");
    oauth2.setClientSecret("DATEV_CLIENT_SECRET");

    oauth2.setCodeChallenge(true);
    oauth2.setCodeChallengeMethod("S256");

    oauth2.setScope("openid profile email datev:accounting:clients accounting:documents datev:accounting:extf-files-import");

    // Begin the OAuth2 authorization code flow.  This returns a URL that should be loaded in a browser.
    const url = oauth2.startAuth(alloc) catch {
        std.debug.print("{s}\n", .{try oauth2.getLastErrorText(alloc)});
        return;
    };

    // Launch the default browser on the system and navigate to the url.
    // The LaunchBrowser method was added in Chilkat v10.1.2.
    oauth2.launchBrowser(url) catch {
        std.debug.print("{s}\n", .{try oauth2.getLastErrorText(alloc)});
        return;
    };

    // Wait for the interactive user to grant permission in the interactive browser session.
    // We'll wait for a max of 90 seconds.
    var num_ms_waited: i32 = 0;
    while ((num_ms_waited < 90000) and (oauth2.getAuthFlowState() < 3)) {
        oauth2.sleepMs(100);
        num_ms_waited = num_ms_waited + 100;
    }

    // If there was no response from the browser within 90 seconds, then
    // the AuthFlowState will be equal to 1 or 2.
    // 1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
    // 2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
    // In that case, cancel the background task started in the call to StartAuth.
    if (oauth2.getAuthFlowState() < 3) {
        oauth2.cancel() catch {};
        std.debug.print("No response from the browser!\n", .{});
        return;
    }

    // Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
    // The possible AuthFlowState values are:
    // 3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
    // 4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
    // 5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
    if (oauth2.getAuthFlowState() == 5) {
        std.debug.print("OAuth2 failed to complete.\n", .{});
        std.debug.print("{s}\n", .{try oauth2.getFailureInfo(alloc)});
        return;
    }

    if (oauth2.getAuthFlowState() == 4) {
        std.debug.print("OAuth2 authorization was denied.\n", .{});
        std.debug.print("{s}\n", .{try oauth2.getAccessTokenResponse(alloc)});
        return;
    }

    if (oauth2.getAuthFlowState() != 3) {
        std.debug.print("Unexpected AuthFlowState:{d}\n", .{oauth2.getAuthFlowState()});
        return;
    }

    // Save the full JSON access token response to a file.
    const sb_json = try chilkat.StringBuilder.init();
    defer sb_json.deinit();
    sb_json.append(try oauth2.getAccessTokenResponse(alloc)) catch {};
    sb_json.writeFile("qa_data/tokens/datev.json", "utf-8", false) catch {};

    // The saved JSON response looks like this:

    // {
    //     "refresh_token": "ZDA5Y .... FFhTXc9",
    //     "refresh_token_expires_in": 39600,
    //     "id_token": "eyJ .... Q9w",
    //     "access_token": "MTM .... 1UDA9",
    //     "token_type": "bearer",
    //     "expires_in": 900
    // }

    std.debug.print("OAuth2 authorization granted!\n", .{});
    std.debug.print("Access Token = {s}\n", .{try oauth2.getAccessToken(alloc)});
}