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Start using the library

Examples on how to use the library:

  • libraries to use
  • instantiate a client
  • manage your handle

With this example you can start using the B2HANDLE library in 5 minutes.

Libraries to import​

At the beginning of your python code just import

#!/usr/bin/env python

import sys
import b2handle
from b2handle.clientcredentials import PIDClientCredentials
from b2handle.handleclient import EUDATHandleClient
from b2handle.handleexceptions import *
from requests.exceptions import SSLError

Instantiate your client​

The first thing you have to do is to instantiate your client.

But before that you have to create a json file with the necessary data to connect to the handle server. The file uses certificates in order to authenticate with the Handle server.


{
  "handle_server_url": "https://myserver.com",
  "private_key": "privkey.pem",
  "certificate_only": "certificate_only.pem",
  "prefix": "21.11111",
  "handleowner": "301:11239/ADMINUSER",
  "HTTPS_verify": "True"
}

Then instantiate your client

    print "Creating credentials"
    cred = PIDClientCredentials.load_from_JSON('mycredentials.json')
    client = EUDATHandleClient.instantiate_with_credentials(cred)

    print('PID prefix ' + cred.get_prefix())
    print('Server ' + cred.get_server_URL())

Manage your handle​

The Example​

The example we are going to follow is to create is as follows

The data of the test handle​

In this section we set the data for the test handle.

    TEST_SUFFIX='MYTEST-HANDLE'
    VALUE_ORIG='http://www.example.com/1'
    VALUE_AFTER='http://www.example.com/2'
    handle = cred.get_prefix() + '/' + TEST_SUFFIX

Now that we have the data lets start managing the handle.

Creata a test handle​

The creation of a handle is the first available action which is supported with register_handle. Basic interactions

You may either register a new Handle with a unique random name (random UUID) or with a predefine value.

In this example we are creating a handle with the name TEST_SUFFIX='MYTEST-HANDLE'

    # Create test
    print "Creating handle " + handle
    create_result = client.register_handle(handle, VALUE_ORIG)

    if create_result == handle:
        print "OK: Create handle successful."
    else:
        print "PROBLEM: Create handle returned unexpected response."

Read test handle​

With the get_value_from_handle you may retrieve a single value from a single Handle. If several entries with this key exist, the methods returns the first one. If the handle does not exist, the method will raise an exception .Basic interactions

In this example we are reading the predefined handle with key=URL.

    # Read test
    key = 'URL'
    read_value = client.get_value_from_handle(handle, key)
        
    if read_value == VALUE_ORIG:
        print "OK: Read handle successful."
    else:
        print "PROBLEM: Read handle returned unexpected response."

Modify test handle​

The library supports the modification of a value in the handle. Basic interactions

With modify_handle_value() a user can modify any number of values in a specific Handle record.

In this example we are going to update the URL of the handle record with the value VALUE_AFTER

    # Modify test
    key = 'URL'
    client.modify_handle_value(handle, **{key: VALUE_AFTER} )
    get_value_result = client.get_value_from_handle(handle, key)

    if get_value_result == VALUE_AFTER:
        print "OK: Modify handle successful."
    else:
        print "CRITICAL: Modify handle value returned unexpected value."
        print "Expected : " + VALUE_AFTER
        print "Returned : " + get_value_result

Delete test handle​

The library supports the Deletion of the handle and its handle record with the delete_function. Basic interactions

In this example we are going to delete the handle we previously created.

    # Delete test
    delete_result = client.delete_handle(handle)
    print "OK: Delete handle successfully."