Custom Azure Blob Storage Provider
Create Custom Azure Blob Providers to extend or take over the built-in functionality.
To create a Custom Azure Blob Provider, you will need to:
You might also be interested in the Other Scenarios we have on this topic.
Create the Provider Class
Create a Class which inherits from the Telerik.Web.UI.AzureProvider and add your overrides.
Example
using System;
using Telerik.Web.UI;
namespace MyNamespace
{
public class CustomAzureProvider : AzureProvider
{
// Override the methods
}
}
Imports System
Imports Telerik.Web.UI
Namespace MyNamespace
Public Class CustomAzureProvider
Inherits AzureProvider
'Override the methods
End Class
End Namespace
Register the provider in web.config
Register the newly created Custom Providers in the web.config
Example
<telerik.web.ui>
<radCloudUpload>
<storageProviders>
<!-- Add a new storage with a Type of the Custom Provider. Note that the Type is a combination of the name space and the class name. -->
<add name="Azure" type="MyNamespace.CustomAzureProvider"/>
</storageProviders>
</radCloudUpload>
</telerik.web.ui>
</configuration>
Add the Overrides
By adding Overrides to the Custom Provider, you will be able to take Control over the Provider's methods.
Examples of Overrides:
Setting the Credentials
To set the Azure credentials for the custom provider, override its Initialize method and set the values to the AccountKey, AccountName, and BlobContainer properties.
Example
public override void Initialize(string name, System.Collections.Specialized.NameValueCollection config)
{
AccountKey = "{ACCOUNT_KEY}";
AccountName = "{ACCOUNT_NAME}";
BlobContainer = "{BLOB_CONTAINER}";
SubFolderStructure = "{SUB_FOLDER_STRUCTURE}/";
}
Public Overrides Sub Initialize(name As String, config As System.Collections.Specialized.NameValueCollection)
AccountKey = "{ACCOUNT_KEY}"
AccountName = "{ACCOUNT_NAME}"
BlobContainer = "{BLOB_CONTAINER}"
SubFolderStructure = "{SUB_FOLDER_STRUCTURE}/"
End Sub
In case you have set the required values during the registration in the web.config, the values will be present in the config parameter (NameValueCollection)
Example
public override void Initialize(string name, System.Collections.Specialized.NameValueCollection config)
{
//Values from the config NameValueCollection are passed from the web.config file.
AccountKey = config["accountKey"];
AccountName = config["accountName"];
BlobContainer = config["blobContainer"];
SubFolderStructure = config["subFolderStructure"];
UncommitedFilesExpirationPeriod = config["uncommitedFilesExpirationPeriod"];
}
Public Overrides Sub Initialize(name As String, config As System.Collections.Specialized.NameValueCollection)
'Values from the config NameValueCollection are passed from the web.config file.
AccountKey = config("accountKey")
AccountName = config("accountName")
BlobContainer = config("blobContainer")
SubFolderStructure = config("subFolderStructure")
UncommitedFilesExpirationPeriod = config("uncommitedFilesExpirationPeriod")
End Sub
Append a forward slash "
/" to the value provided in the SubFolderStructure property for the directory to work. Otherwise, the file will be uploaded to the main container with its name containing the value from the SubFolderStructure property.
Upload Files with their original name
By default the CloudUpload will prepend the Guid to the uploaded file names to prevent overriding existing ones. To keep the original filename, override the UploadFile customize the full path (DirectoryStructure/FileName.ext) that well be used to upload the files to the Azure Blob Storage.
Example
public override void UploadFile(string keyName, NameValueCollection metaData, Stream fileStream)
{
// Get the original filename from the metadata parameter
string originalFileName = metaData["fileName"];
// build the full path with a new file name by concatenating the SubFolderStructure and the original filename
string pathWithNewFileName = string.Format("{0}{1}", SubFolderStructure, originalFileName);
// overwrite the keyName param with the new value
keyName = pathWithNewFileName;
// Call the base UploadFile() method
base.UploadFile(keyName, metaData, fileStream);
}
Public Overrides Sub UploadFile(ByVal keyName As String, ByVal metaData As NameValueCollection, ByVal fileStream As Stream)
'Get the original filename from the metadata parameter
Dim originalFileName As String = metaData("fileName")
'build the full path with a new file name by concatenating the SubFolderStructure and the original filename
Dim pathWithNewFileName As String = String.Format("{0}{1}", SubFolderStructure, originalFileName)
'overwrite the keyName param with the new value
keyName = pathWithNewFileName
'Call the base UploadFile() method
MyBase.UploadFile(keyName, metaData, fileStream)
End Sub
Other Scenarios
One common scenario includes uploading files to different Azure Blob Containers based logged in user, based on file-type, etc. To do so, you can create multiple Custom Azure Providers and switch between them.
Follow the instructions from the Switching between Custom Azure Providers section.
Switching between Custom Azure Providers
To test it out, create two Custom Azure Providers
Example Custom Azure Provider 1
using System;
using Telerik.Web.UI;
namespace MyNamespace
{
public class CustomAzureProvider1 : AzureProvider
{
// Overrides for Custom Azure Provider 1
}
}
Imports System
Imports Telerik.Web.UI
Namespace MyNamespace
Public Class CustomAzureProvider1
Inherits AzureProvider
'Overrides for Custom Azure Provider 1
End Class
End Namespace
Example Custom Azure Provider 2
using Telerik.Web.UI;
namespace MyNamespace
{
public class CustomAzureProvider2 : AzureProvider
{
// Overrides for Custom Azure Provider 2
}
}
Imports Telerik.Web.UI
Namespace MyNamespace
Public Class CustomAzureProvider2
Inherits AzureProvider
'Overrides for Custom Azure Provider 2
End Class
End Namespace
Register the newly created Custom Azure Providers in the web.config
Example
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<sectionGroup name="telerik.web.ui">
<section name="radCloudUpload" type="Telerik.Web.UI.CloudUploadConfigurationSection" allowDefinition="MachineToApplication" requirePermission="false" />
</sectionGroup>
</configSections>
...
<telerik.web.ui>
<radCloudUpload>
<storageProviders>
<!-- Add a new storage providers with a Type of the Custom Provider. Note that the Type is a combination of the name space and the class name. -->
<add name="CustomAzureProvider1 " type="MyNamespace.CustomAzureProvider1"/>
<!--Keys defined in the configuration file-->
<add name="CustomAzureProvider2 " type="MyNamespace.CustomAzureProvider2" accountKey="{ACCOUNT_KEY}" accountName="{ACCOUNT_NAME}" blobContainer="{BLOB_CONTAINER}" subFolderStructure="{SUB_FOLDER-STRUCTURE}" ensureContainer="true" uncommitedFilesExpirationPeriod="2" defaultEndpointsProtocol="https" />
</storageProviders>
</radCloudUpload>
</telerik.web.ui>
</configuration>
Create a Custom CloudUpload Handler which will switch between the Custom Azure Providers
Example CustomCloudUploadHandler.ashx
<%@ WebHandler Language="C#" Class="CustomCloudUploadHandler" %>
using System;
using System.Web;
public class CustomCloudUploadHandler : Telerik.Web.UI.CloudUploadHandler {
public override void SetCustomProvider(object sender, Telerik.Web.UI.CloudUpload.CustomProviderSetupEventArgs e)
{
//Check for some condition and select Custom Provider
if (true)
{
e.Name = "CustomAzureProvider1";
}
else
{
e.Name = "CustomAzureProvider2";
}
}
}
<%@ WebHandler Language="VB" Class="CustomCloudUploadHandler" %>
Imports System
Imports System.Web
Public Class CustomCloudUploadHandler
Inherits Telerik.Web.UI.CloudUploadHandler
Public Overrides Sub SetCustomProvider(ByVal sender As Object, ByVal e As Telerik.Web.UI.CloudUpload.CustomProviderSetupEventArgs)
If True Then
e.Name = "CustomAzureProvider1"
Else
e.Name = "CustomAzureProvider2"
End If
End Sub
End Class
Finally, assign the Custom CloudUpload Handler to the CloudUpload control by providing the url to the ProviderType property.
Example
<telerik:RadCloudUpload ID="RadCloudUpload1" runat="server" ProviderType="Azure" HttpHandlerUrl="~/CustomCloudUploadHandler.ashx"></telerik:RadCloudUpload>