3.5. Retrieving a List of Resources from a Collection

In these examples a list of resources is retrieved from a collection using the list method.

Example 3.3. Retrieving a List of all Resources in a Collection

Retrieving a list of all resources in the datacenters collection. The query parameter of the list method allows the use of engine based queries. In this way the SDK supports the use of queries in the same format as those executed in the Administration and User Portals. The query parameter is also the mechanism for providing pagination arguments while iterating through the collection. 
dc_list = []
dc_page_index = 1
dc_page_current = api.datacenters.list(query="page %s" % dc_page_index)
while(len(dc_page_current) != 0):
    dc_list = dc_list + dc_page_current
    dc_page_index = dc_page_index + 1
    dc_page_current = api.datacenters.list(query="page %s" % dc_page_index)
In this example the list of resources contained in the datacenters collection is ultimately stored in the locally defined dc_list list variable.

Warning

The list method of a collection is restricted to returning only as many elements as allowed by the SearchResultsLimit Red Hat Virtualization Manager configuration key.
To ensure that all records in a the list are returned it is recommended that you paginate through the results as illustrated in this example.
Alternatively you may choose to set the max parameter of the list method to the maximum number of records that you wish to retrieve.

Example 3.4. Retrieving a List of Resources in a Collection Matching a Keyword Based Filter

Retrieving a list of all resources in the datacenters collection that have a storage type of nfs. In this example both the query parameter and **kwargs parameter are supplied. The query is used for pagination in the same way as illustrated in the previous example. The **kwargs parameter is used to filter based on the storage type of the data center. 
dc_list = []
dc_page_index = 1
dc_page_current = api.datacenters.list(query="page %s" % dc_page_index, **{"storage_type": "nfs"})
while(len(dc_page_current) != 0):
    dc_list = dc_list + dc_page_current
    dc_page_index = dc_page_index + 1
    dc_page_current = api.datacenters.list(query="page %s" % dc_page_index, **{"storage_type": "nfs"})
In this example the list of resources contained in the datacenters collection with a storage type of nfs is ultimately stored in the locally defined dc_list list variable.