edge

Access information about page connections.

Edges represent the connections between resources. They are implemented as tuples `{EdgeId, SubjectId, PredicateId, ObjectId, OrderNr}`. The edge id is a unique id representing the edge, it can be used with edit actions. The OrderNr defines the order of the edges with respect to the subject.

Most edge information is accessed using the m_rsc model, but some information can only accessed with the m_edge model.

This model implements two template accessible options. They are mainly used to obtain the edge's id for edit pages.

The following m_edge model properties are available in templates:

Example return value for {% print m.edge[10635] %}:

[{about,[[{id,86060},
          {subject_id,10635},
          {predicate_id,300},
          {name,<<"about">>},
          {object_id,17433},
          {seq,1},
          {created,{{2015,11,17},{11,22,11}}},
          {creator_id,1}]]},
 {author,[[{id,6},
           {subject_id,10635},
           {predicate_id,301},
           {name,<<"author">>},
           {object_id,10634},
           {seq,1000000},
           {created,{{2015,2,3},{16,23,20}}},
           {creator_id,1}]]}]

Other Topics

model/edge/post/o/+subject/+predicate/+object or model/edge/post/s/+object/+predicate/+subject inserts a new edge between resources.

The posted message can optionally include the name or id of the object, predicate and subject.

cotonic.broker.publish("bridge/origin/edge/post/o/4312",
                       {
                         predicate: "author",
                         subject: 7575
                       });

It is also possible to insert edges via cotonics onclick topics.

<div data-onclick-topic="bridge/origin/model/edge/post/o/{{ id }}/?/{{ m.acl.user }}">
   <button data-edge-predicate="is_going">Is Going</button>
   <button data-edge-predicate="is_interested">Might Go</button>
</div>

When a user clicks on a button, the model retrieves the predicate name (or id) from the data-edge-predicate attribute. This is also possible by for the object and subject attributes of the edge. When there is a ? in the topic path, the value can be retrieved from a data attribute. The attribute value for object is: data-edge-object. For subject it is: data-edge-subject. If all path parts from the first ? to the end are ?, then those trailing ? parts may be omitted from the topic path.

model/edge/delete/o/+subject/+predicate/+object, model/edge/delete/s/+object/+predicate/+subject or model/edge/delete/edge/+edge_id deletes the specified edge.

cotonic.broker.publish("bridge/origin/edge/delete/edge/6776");

Or via a onclick topic.

<button data-onclick-topic="bridge/origin/edge/delete/{{ edge_id }}">Delete</button

Available Model API Paths

/+name marks a variable path segment. A trailing /... means extra path segments are accepted for further lookups.

Post Method Examples

Path orientation notes:

• Object-oriented path (/o/...) uses order: subject / predicate / object.

• Subject-oriented path (/s/...) uses order: object / predicate / subject.

• Both forms create or delete the same edge triple in storage: (subject, predicate, object).

• Trailing wildcard parts can be omitted: if all path parts from the first ? to the end are ?, you may stop the path at that first ?.

Insert via object-oriented path:

cotonic.broker.call(
    "bridge/origin/model/edge/post/o/7575/author/4312",
    {}
);

Insert via wildcard path values (?) resolved from payload:

cotonic.broker.call(
    "bridge/origin/model/edge/post/o/?/?/?",
    {
        subject: 7575,
        predicate: "author",
        object: 4312
    }
);

Insert with trailing wildcards omitted (only subject in path, predicate/object from payload):

cotonic.broker.call(
    "bridge/origin/model/edge/post/o/7575",
    {
        predicate: "author",
        object: 4312
    }
);

Insert with all values from payload (shortest path):

cotonic.broker.call(
    "bridge/origin/model/edge/post/o",
    {
        subject: 7575,
        predicate: "author",
        object: 4312
    }
);

Insert via subject-oriented path:

cotonic.broker.call(
    "bridge/origin/model/edge/post/s/4312/author/7575",
    {}
);

See also

m_rsc, m_media