(Classic ASP) Azure Blob - Get Tags (Check if Blob Exists)

See more Azure Cloud Storage Examples

Gets the user-defined tags for a specified blob. This can also be used as a way to check to see if a blob exists.

For more information, see https://learn.microsoft.com/en-us/rest/api/storageservices/get-blob-tags

Chilkat ActiveX Downloads

ActiveX for 32-bit and 64-bit Windows

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

' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.Rest")
set rest = Server.CreateObject("Chilkat.Rest")

' Connect to the Azure Storage Blob Service
bTls = 1
port = 443
bAutoReconnect = 1
' In this example, the storage account name is "chilkat".
success = rest.Connect("chilkat.blob.core.windows.net",port,bTls,bAutoReconnect)
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( rest.LastErrorText) & "</pre>"
    Response.End
End If

' Provide Azure Cloud credentials for the REST call.
' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.AuthAzureStorage")
set azAuth = Server.CreateObject("Chilkat.AuthAzureStorage")
azAuth.AccessKey = "AZURE_ACCESS_KEY"
' The account name used here should match the 1st part of the domain passed in the call to Connect (above).
azAuth.Account = "chilkat"
azAuth.Scheme = "SharedKey"
azAuth.Service = "Blob"
' This causes the "x-ms-version: 2021-08-06" header to be automatically added.
azAuth.XMsVersion = "2021-08-06"
success = rest.SetAuthAzureStorage(azAuth)

' Note: The application does not need to explicitly set the following
' headers: Content-Length, x-ms-date, Authorization.  These headers
' are automatically set by Chilkat.

' The Azure blob container is "test", the file is "helloWorld.txt"
' Add "?comp=tags" to get the user-defined tags instead of the actual blob content.
' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.StringBuilder")
set sb = Server.CreateObject("Chilkat.StringBuilder")
success = rest.FullRequestNoBodySb("GET","/test/helloWorldajdfadf.txt?comp=tags",sb)
If (success = 0) Then
    ' Examine the request/response to see what happened.
    Response.Write "<pre>" & Server.HTMLEncode( "response status code = " & rest.ResponseStatusCode) & "</pre>"
    Response.Write "<pre>" & Server.HTMLEncode( "response status text = " & rest.ResponseStatusText) & "</pre>"
    Response.Write "<pre>" & Server.HTMLEncode( "response header: " & rest.ResponseHeader) & "</pre>"
    Response.Write "<pre>" & Server.HTMLEncode( "---") & "</pre>"
    Response.Write "<pre>" & Server.HTMLEncode( "LastRequestStartLine: " & rest.LastRequestStartLine) & "</pre>"
    Response.Write "<pre>" & Server.HTMLEncode( "LastRequestHeader: " & rest.LastRequestHeader) & "</pre>"
    Response.End
End If

' A typical blob with no tags will return this:

' <?xml version="1.0" encoding="utf-8"?>
' <Tags><TagSet/></Tags>

' If the blob does not exist, you get this:

' <?xml version="1.0" encoding="utf-8"?>
' <Error>
'     <Code>BlobNotFound</Code>
'     <Message>The specified blob does not exist.
' 	RequestId:fcfefdd9-301e-001a-2135-3a23d2000000
' 	Time:2023-02-06T14:17:00.7805577Z
'     </Message>
' </Error>

Response.Write "<pre>" & Server.HTMLEncode( sb.GetAsString()) & "</pre>"

' To see if we got Tags or an Error, then examine the XML.
' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.Xml")
set xml = Server.CreateObject("Chilkat.Xml")
success = xml.LoadSb(sb,1)

' Examine the tag..
If (xml.TagEquals("Tags") = 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( "Blob exists!") & "</pre>"
Else

    If (xml.ChildContentMatches("Code","BlobNotFound",1) = 1) Then
        Response.Write "<pre>" & Server.HTMLEncode( "Blob does not exist.") & "</pre>"
    Else
        Response.Write "<pre>" & Server.HTMLEncode( "Some other error...") & "</pre>"
    End If

End If

Response.Write "<pre>" & Server.HTMLEncode( "Success.") & "</pre>"

%>
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