How can I get the Categories and Keyword hierarchy using OData?
When I tried to retrieve Keywords using [OData Service Object].Keywords, I get all of the Keywords. However, the parent is null and children count is 0, so I am unable to create the hierarchy.
Also, how can I get the Components and/or Pages that are associated to each Keyword using OData?
Try the below OData query to get the Parent and Child keyword hierarchy details.
/odata.svc/Publications(362)/Keywords/?$expand=Children,Parent
This is one web service call and once you have the results, use LINQ to query for a specific keyword.
The above using OData expand option to get Parent and Child node details.
e.g;
expand=Node1 --> expands Node1
expand=Node1,Node2 --> expands Node1 and Node2.
Hope this will help.
If you look at http://myserver.com/odata.svc/Keywords you'll see a linear collection of Keyword entities. Keywords that are nested within other Keywords (i.e. Children) will have a <link href=".../Parent" /> property point to the parent keyword, while any Keywords that have nested Keyword (i.e. Parents) will have HasChildren=true and <link href=".../Children /> point to a list of child Keyword entities.
The way that you can traverse the tree is by making separate web service calls to either get children or get parents via the <link> properties. As Ram mentioned you can use $expand to get the relationships in one call.
$expand" on them.