(SQL Server) Lower-Level REST API Methods (Google Cloud Storage)

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.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- This example demonstrates a REST call using SendReqStringBody, ReadResonseHeader, and ReadRespBodyString.
    -- It will create a bucket in Google Cloud Storage.
    DECLARE @success int

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

    DECLARE @gAuth int
    -- Use "Chilkat_9_5_0.AuthGoogle" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.AuthGoogle', @gAuth OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    -- 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

    DECLARE @rest int
    -- Use "Chilkat_9_5_0.Rest" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Rest', @rest OUT

    -- Connect using TLS.
    DECLARE @bAutoReconnect int
    SELECT @bAutoReconnect = 1
    EXEC sp_OAMethod @rest, 'Connect', @success OUT, 'www.googleapis.com', 443, 1, @bAutoReconnect

    -- Provide the authentication credentials (i.e. the access key)
    EXEC sp_OAMethod @rest, 'SetAuthGoogle', @success OUT, @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..
    DECLARE @jsonReqBody int
    -- Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @jsonReqBody OUT

    EXEC sp_OAMethod @jsonReqBody, 'AddStringAt', @success OUT, -1, 'name', 'chilkat-bucket-c'
    EXEC sp_OAMethod @jsonReqBody, 'AddStringAt', @success OUT, -1, 'kind', 'storage#bucket'
    EXEC sp_OAMethod @jsonReqBody, 'AddStringAt', @success OUT, -1, 'location', 'US'
    EXEC sp_OAMethod @jsonReqBody, 'AddObjectAt', @success OUT, -1, 'versioning'

    DECLARE @pObjVersioning int
    EXEC sp_OAMethod @jsonReqBody, 'ObjectOf', @pObjVersioning OUT, 'versioning'
    EXEC sp_OAMethod @pObjVersioning, 'AddBoolAt', @success OUT, -1, 'enabled', 1
    EXEC @hr = sp_OADestroy @pObjVersioning

    -- Show the HTTP request body we'll be sending.
    EXEC sp_OAMethod @jsonReqBody, 'Emit', @sTmp0 OUT
    PRINT @sTmp0

    -- Add the required query parameter.
    -- See https://cloud.google.com/storage/docs/json_api/v1/buckets/insert
    EXEC sp_OAMethod @rest, 'AddQueryParam', @success OUT, 'project', 'chilkattest-1050'

    -- Add the Content-Type HTTP request header.
    EXEC sp_OAMethod @rest, 'AddHeader', @success OUT, 'Content-Type', 'application/json; charset=UTF-8'

    -- Send the REST HTTP request.
    EXEC sp_OAMethod @jsonReqBody, 'Emit', @sTmp0 OUT
    EXEC sp_OAMethod @rest, 'SendReqStringBody', @success OUT, 'POST', '/storage/v1/b', @sTmp0
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @rest, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @gAuth
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @jsonReqBody
        RETURN
      END

    -- Read the response header.
    DECLARE @responseStatusCode int
    EXEC sp_OAMethod @rest, 'ReadResponseHeader', @responseStatusCode OUT
    IF @responseStatusCode < 0
      BEGIN
        -- We were unable to receive the response header.
        EXEC sp_OAGetProperty @rest, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @gAuth
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @jsonReqBody
        RETURN
      END

    IF @responseStatusCode <> 200
      BEGIN
        -- 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:

        EXEC sp_OAGetProperty @rest, 'ResponseStatusText', @sTmp0 OUT
        PRINT 'Response status text: ' + @sTmp0

        EXEC sp_OAGetProperty @rest, 'ResponseHeader', @sTmp0 OUT
        PRINT 'Response header: ' + @sTmp0
      END

    -- Read the response body.  In this case we're expecting it to be JSON..
    DECLARE @responseBodyStr nvarchar(4000)
    EXEC sp_OAMethod @rest, 'ReadRespBodyString', @responseBodyStr OUT
    EXEC sp_OAGetProperty @rest, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        -- 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.
        EXEC sp_OAGetProperty @rest, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @gAuth
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @jsonReqBody
        RETURN
      END

    -- Show the JSON response.

    PRINT 'Json Response: ' + @responseBodyStr

    EXEC @hr = sp_OADestroy @gAuth
    EXEC @hr = sp_OADestroy @rest
    EXEC @hr = sp_OADestroy @jsonReqBody


END
GO