(Visual FoxPro) Get Object MetaData from Google Cloud Storage

Demonstrates how to download a Google Cloud Storage object's metadata.

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

LOCAL loSbToken
LOCAL loHttp
LOCAL lcUrl
LOCAL loSbMetaData
LOCAL lnSuccess
LOCAL lnResponseCode

* This example requires the Chilkat API to have been previously unlocked.
* See Global Unlock Sample for sample code.

* This example uses a previously obtained access token having permission for the 
* scope "https://www.googleapis.com/auth/cloud-platform"

* In this example, Get Google Cloud Storage OAuth2 Access Token, 
* the service account access token was saved to a text file.  This example fetches the access token from the file..
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbToken = CreateObject('Chilkat.StringBuilder')
loSbToken.LoadFile("qa_data/tokens/googleCloudStorageAccessToken.txt","utf-8")

* Send a GET equivalent to this curl command.

* curl -X GET \
*     -H "Authorization: Bearer [OAUTH2_TOKEN]" \
*     -o "[SAVE_TO_LOCATION]" \
*     "https://www.googleapis.com/storage/v1/b/[BUCKET_NAME]/o/[OBJECT_NAME]?projection=full"

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Http')
loHttp = CreateObject('Chilkat.Http')

loHttp.AuthToken = loSbToken.GetAsString()

* Construct a URL to download the metadata for the object named "starfish.jpg" located in the "chilkat-ocean" bucket.
loHttp.SetUrlVar("bucket_name","chilkat-ocean")
loHttp.SetUrlVar("object_name","starfish.jpg")
lcUrl = "https://www.googleapis.com/storage/v1/b/{$bucket_name}/o/{$object_name}?projection=full"

* If there is an error response, then we didn't actually download the metadata,
* but instead we downloaded an error response..
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbMetaData = CreateObject('Chilkat.StringBuilder')
lnSuccess = loHttp.DownloadSb(lcUrl,"utf-8",loSbMetaData)
IF (lnSuccess = 0) THEN
    ? loHttp.LastErrorText
    RELEASE loSbToken
    RELEASE loHttp
    RELEASE loSbMetaData
    CANCEL
ENDIF

lnResponseCode = loHttp.LastStatus
IF (lnResponseCode = 401) THEN
    ? "If invalid credentials, then it is likely the access token expired."
    ? "Your app should automatically fetch a new access token and re-try."
ENDIF

IF (lnResponseCode <> 200) THEN
    ? "Error response code = " + STR(lnResponseCode)
    ? "Error:"
    ? loSbMetaData.GetAsString()
    RELEASE loSbToken
    RELEASE loHttp
    RELEASE loSbMetaData
    CANCEL
ENDIF

? loSbMetaData.GetAsString()
? "Success."

* Sample output:

* {
*  "kind": "storage#object",
*  "id": "chilkat-ocean/starfish.jpg/1502670320090292",
*  "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg",
*  "name": "starfish.jpg",
*  "bucket": "chilkat-ocean",
*  "generation": "1502670320090292",
*  "metageneration": "1",
*  "contentType": "image/jpeg",
*  "timeCreated": "2017-08-14T00:25:20.040Z",
*  "updated": "2017-08-14T00:25:20.040Z",
*  "storageClass": "MULTI_REGIONAL",
*  "timeStorageClassUpdated": "2017-08-14T00:25:20.040Z",
*  "size": "6229",
*  "md5Hash": "LpxZ2/JmI2fcl9/dqF2gSA==",
*  "mediaLink": "https://www.googleapis.com/download/storage/v1/b/chilkat-ocean/o/starfish.jpg?generation=1502670320090292&alt=media",
*  "acl": [
*   {
*    "kind": "storage#objectAccessControl",
*    "id": "chilkat-ocean/starfish.jpg/1502670320090292/project-owners-933037264567",
*    "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/project-owners-933037264567",
*    "bucket": "chilkat-ocean",
*    "object": "starfish.jpg",
*    "generation": "1502670320090292",
*    "entity": "project-owners-933037264567",
*    "role": "OWNER",
*    "projectTeam": {
*     "projectNumber": "933037264567",
*     "team": "owners"
*    },
*    "etag": "CLT5kpW71dUCEAE="
*   },
*   {
*    "kind": "storage#objectAccessControl",
*    "id": "chilkat-ocean/starfish.jpg/1502670320090292/project-editors-933037264567",
*    "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/project-editors-933037264567",
*    "bucket": "chilkat-ocean",
*    "object": "starfish.jpg",
*    "generation": "1502670320090292",
*    "entity": "project-editors-933037264567",
*    "role": "OWNER",
*    "projectTeam": {
*     "projectNumber": "933037264567",
*     "team": "editors"
*    },
*    "etag": "CLT5kpW71dUCEAE="
*   },
*   {
*    "kind": "storage#objectAccessControl",
*    "id": "chilkat-ocean/starfish.jpg/1502670320090292/project-viewers-933037264567",
*    "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/project-viewers-933037264567",
*    "bucket": "chilkat-ocean",
*    "object": "starfish.jpg",
*    "generation": "1502670320090292",
*    "entity": "project-viewers-933037264567",
*    "role": "READER",
*    "projectTeam": {
*     "projectNumber": "933037264567",
*     "team": "viewers"
*    },
*    "etag": "CLT5kpW71dUCEAE="
*   },
*   {
*    "kind": "storage#objectAccessControl",
*    "id": "chilkat-ocean/starfish.jpg/1502670320090292/user-starfish@chilkat-176611.iam.gserviceaccount.com",
*    "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/user-starfish@chilkat-176611.iam.gserviceaccount.com",
*    "bucket": "chilkat-ocean",
*    "object": "starfish.jpg",
*    "generation": "1502670320090292",
*    "entity": "user-starfish@chilkat-176611.iam.gserviceaccount.com",
*    "role": "OWNER",
*    "email": "starfish@chilkat-176611.iam.gserviceaccount.com",
*    "etag": "CLT5kpW71dUCEAE="
*   }
*  ],
*  "owner": {
*   "entity": "user-starfish@chilkat-176611.iam.gserviceaccount.com"
*  },
*  "crc32c": "9RjgwQ==",
*  "etag": "CLT5kpW71dUCEAE="
* }
* 

RELEASE loSbToken
RELEASE loHttp
RELEASE loSbMetaData