Neo4j Ruby - Practical Neo4j - page 236

The Cypher in the delete method begins by finding the user and content that will be used in the rest of the query.
In the first MATCH , you can determine if this status update is the CURRENTPOST by checking to see if it is related to a
NEXTPOST . If this relationship pattern matches, make the NEXTPOST into the CURRENTPOST with CREATE UNIQUE .
Next, the query will ask if the status update is somewhere the middle of the list, which is performed by
determining if the status update has incoming and outgoing NEXTPOST relationships. If the pattern is matched, then
connect the before and after status updates via NEXTPOST .
Regardless of the status update's location in the linked list, retrieve it and its relationships and then delete the
node along with all of its relationships.
To recap, if one of the relationship patterns matches, replace that pattern with the nodes on either side of the status
update in question. Once that has been performed, the node and its relationships can be removed from the graph.

Interest Graph Model
This section looks at the interest graph and examines some basic ways it can be used to explicitly define a degree of
interest. The following topics are covered:

• Adding filters for owned content

• Adding filters for connected content

• Analyzing connected content (count tags)

Interest in Aggregate
Using the /interest route, we retrieve all of the user's tags and their friends' tags by calling, respectively, the
user_tags and tags_in_network methods, which can be found in the Tag service class. This is displayed in
Figure 10-12 in the left-hand column.

Figure 10-12. Filtering the current user's content