Lua Requires Chilkat v11.0.0+

Lower-Level REST API Methods (Google Cloud Storage)

See more REST Examples

The FullRequest* methods, such as FullRequestBinary, FullRequestMultipart, FullRequestNoBody, FullRequestStream, FullRequestString, etc. are high-level REST API methods that both send the request and receive the response. It is often the case that an application needs make a REST call, but with a finer level of control. The Chilkat REST API provides this feature. An application can break a REST call into the following parts:

1. Send the HTTP request. (via the SendReq* methods)
2. Receive the HTTP response header. (ReadResponseHeader)
3. Receive the HTTP response body. (via the ReadRespBody* methods)

This example demonstrates a REST call using SendReqStringBody, ReadResonseHeader, and ReadRespBodyString.

Lua

local chilkat = require("chilkat")

-- This example demonstrates a REST call using SendReqStringBody, ReadResonseHeader, and ReadRespBodyString.
-- It will create a bucket in Google Cloud Storage.

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

local gAuth = chilkat.AuthGoogle.new()
-- Obtain an access token as shown in one of the following examples:
-- See Get Access Token using a Service Account JSON Key
-- See Get Access Token using a P12 File

local rest = chilkat.Rest.new()

-- Connect using TLS.
local bAutoReconnect = true
local success = rest:connect("www.googleapis.com", 443, true, bAutoReconnect)

-- Provide the authentication credentials (i.e. the access key)
success = rest:set_auth_google(gAuth)

-- Build the JSON request body for creating a bucket.
-- The only required property is the "name", but we'll add more
-- to make a better example..
local jsonReqBody = chilkat.JsonObject.new()
success = jsonReqBody:add_string_at(-1, "name", "chilkat-bucket-c")
success = jsonReqBody:add_string_at(-1, "kind", "storage#bucket")
success = jsonReqBody:add_string_at(-1, "location", "US")

local objVersioning = chilkat.JsonObject.new()
jsonReqBody:append_object2("versioning", objVersioning)
success = objVersioning:add_bool_at(-1, "enabled", true)

-- Show the HTTP request body we'll be sending.
print(jsonReqBody:emit())

-- Add the required query parameter.
-- See https://cloud.google.com/storage/docs/json_api/v1/buckets/insert
success = rest:add_query_param("project", "chilkattest-1050")

-- Add the Content-Type HTTP request header.
success = rest:add_header("Content-Type", "application/json; charset=UTF-8")

-- Send the REST HTTP request.
success = rest:send_req_string_body("POST", "/storage/v1/b", jsonReqBody:emit())
if not success then
    print(rest.last_error_text)
    return
end

-- Read the response header.
local responseStatusCode = rest:read_response_header()
if responseStatusCode < 0 then
    -- We were unable to receive the response header.
    print(rest.last_error_text)
    return
end

if responseStatusCode ~= 200 then
    -- The response was not successful.  We'll still need to receive
    -- the response body, which may contain an error message from the server.
    -- If the response has no body, then the method for reading the
    -- response body can still be called.  It will simply return with an empty
    -- response body.

    -- We can examine the response header and status text:
    print("Response status text: " .. rest.response_status_text)
    print("Response header: " .. rest.response_header)
end

-- Read the response body.  In this case we're expecting it to be JSON..
local responseBodyStr = rest:read_resp_body_string()
if not rest.last_method_success then
    -- We were unable to receive the response body.
    -- Note: If the response did not include a body (such as for cases where
    -- the Content-Length header is 0, or if the response status code implicitly
    -- indicates no body, then ReadRespBodyString returns cktrue, and the
    -- responseBodyString will be an empty string.
    print(rest.last_error_text)
    return
end

-- Show the JSON response.
print("Json Response: " .. responseBodyStr)