Zig Requires Chilkat v11.0.0+

REST Follow Redirects

See more REST Examples

Demonstrates how to follow a 302/303 redirect response. 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.

    const rest = try chilkat.Rest.init();
    defer rest.deinit();

    const b_tls = true;
    const port = 443;
    const b_auto_reconnect = true;
    rest.connect("chilkatsoft.com", port, b_tls, b_auto_reconnect) catch {
        std.debug.print("{s}\n", .{try rest.getLastErrorText(alloc)});
        return;
    };

    // Send a POST to a URL that will respond with a 302 redirect..
    rest.addQueryParam("firstName", "John") catch {};
    rest.addQueryParam("lastName", "Doe") catch {};
    var response_text: [:0]const u8 = rest.fullRequestFormUrlEncoded(alloc, "POST", "/echoPost302.asp") catch {
        std.debug.print("{s}\n", .{try rest.getLastErrorText(alloc)});
        return;
    };

    const status_code = rest.getResponseStatusCode();

    // Examine the response status code
    if (status_code < 300) {
        std.debug.print("Not a redirect.\n", .{});
        std.debug.print("{s}\n", .{response_text});
        return;
    }

    if (status_code > 399) {
        std.debug.print("Error response: Status code = {d}\n", .{status_code});
        std.debug.print("{s}\n", .{response_text});
        return;
    }

    std.debug.print("Redirect status code = {d}\n", .{status_code});

    // The response header will contain a Location field with the redirect URL, such as this:
    // Location: http://www.chilkatsoft.com/echoPostFinal.asp

    // The response status code determines how the client should behave.
    // Here are some common possibilities:

    // 301: Moved Permanently
    // This and all future requests should be directed to the given URI.  (Keep the original HTTP method for the redirect.  In this case, the
    // original request was a POST, so we POST to the redirect URL.)

    // 302: Found (aka Object Moved aka Moved Temporarily)
    // This is the most popular redirect code, but also an example of industrial practice contradicting the standard. HTTP/1.0 specification (RFC 1945 ) required the client
    // to perform a temporary redirect (the original describing phrase was �Moved Temporarily�), but popular browsers implemented it as a 303 See Other. Therefore, HTTP/1.1
    // added status codes 303 and 307 to disambiguate between the two behaviors. However, the majority of Web applications and frameworks still use the 302 status code
    // as if it were the 303.

    // 303: See Other
    // The response to the request can be found under another URI using a GET method. When received in response to a PUT, it should be assumed that the server has
    // received the data and the redirect should be issued with a separate GET message.

    // 307: Temporary Redirect
    // In this occasion, the request should be repeated with another URI, but future requests can still use the original URI. In contrast to 303, the request method
    // should not be changed when reissuing the original request. For instance, a POST request must be repeated using another POST request.

    std.debug.print("{s}\n", .{try rest.getResponseHeader(alloc)});

    // Get the redirect URL
    const url_str = try rest.getLastRedirectUrl(alloc);
    if (!rest.getLastMethodSuccess()) {
        std.debug.print("No Location header found for redirect.\n", .{});
        return;
    }

    const redirect_url = try chilkat.Url.init();
    defer redirect_url.deinit();
    redirect_url.parseUrl(url_str) catch {};

    // Prep for the redirect..
    rest.clearAllParts() catch {};

    // Disconnect and re-connect.
    // (This can be skipped if both the host and SSL/TLS conditions are the same.)
    rest.disconnect(100) catch {};
    rest.connect(try redirect_url.getHost(alloc), redirect_url.getPort(), redirect_url.getSsl(), b_auto_reconnect) catch {
        std.debug.print("{s}\n", .{try rest.getLastErrorText(alloc)});
        return;
    };

    if ((status_code == 301) or (status_code == 307)) {
        // Redirect using a POST, sending the same params to the new destination
        rest.addQueryParam("firstName", "John") catch {};
        rest.addQueryParam("lastName", "Doe") catch {};
        response_text = rest.fullRequestFormUrlEncoded(alloc, "POST", try redirect_url.getPath(alloc)) catch {
            std.debug.print("{s}\n", .{try rest.getLastErrorText(alloc)});
            return;
        };
    }

    if ((status_code == 302) or (status_code == 303)) {
        // Redirect using a GET, sending the query params found in the redirect URL.
        response_text = rest.fullRequestFormUrlEncoded(alloc, "GET", try redirect_url.getPathWithQueryParams(alloc)) catch {
            std.debug.print("{s}\n", .{try rest.getLastErrorText(alloc)});
            return;
        };
    }

    // Show the final status code and the response text.
    std.debug.print("Final status code = {d}\n", .{rest.getResponseStatusCode()});

    std.debug.print("Final response text (HTML, XML, JSON, or whatever..)\n", .{});
    std.debug.print("{s}\n", .{response_text});
}