Merge pull request #21 from tapglue/connection-pagination

Add pagination to connection listed by state

core/connection.go

@@ -21,6 +21,7 @@ type ConnectionByStateFunc func(
 	currentApp *app.App,
 	originID uint64,
 	state connection.State,
+	opts connection.QueryOptions,
 ) (*ConnectionFeed, error)
 
 // ConnectionByState returns all connections for the given origin and state.
@@ -32,6 +33,7 @@ func ConnectionByState(
 		currentApp *app.App,
 		originID uint64,
 		state connection.State,
+		opts connection.QueryOptions,
 	) (*ConnectionFeed, error) {
 		switch state {
 		case connection.StatePending, connection.StateConfirmed, connection.StateRejected:
@@ -41,34 +43,61 @@ func ConnectionByState(
 		}
 
 		ics, err := connections.Query(currentApp.Namespace(), connection.QueryOptions{
+			Before:  opts.Before,
 			Enabled: &defaultEnabled,
 			FromIDs: []uint64{originID},
+			Limit:   opts.Limit,
 			States:  []connection.State{state},
 		})
 		if err != nil {
 			return nil, err
 		}
 
 		ocs, err := connections.Query(currentApp.Namespace(), connection.QueryOptions{
+			Before:  opts.Before,
 			Enabled: &defaultEnabled,
+			Limit:   opts.Limit,
 			States:  []connection.State{state},
 			ToIDs:   []uint64{originID},
 		})
 		if err != nil {
 			return nil, err
 		}
 
+		cons := append(ics, ocs...)
+
+		if len(cons) == 0 {
+			return &ConnectionFeed{
+				Connections: connection.List{},
+				UserMap:     user.Map{},
+			}, nil
+		}
+
+		if len(cons) > opts.Limit {
+			cons = cons[:opts.Limit-1]
+		}
+
+		ids := []uint64{}
+
+		for _, c := range cons {
+			if c.FromID == originID {
+				ids = append(ids, c.ToID)
+			} else {
+				ids = append(ids, c.FromID)
+			}
+		}
+
 		um, err := user.MapFromIDs(
 			users,
 			currentApp.Namespace(),
-			append(ics.ToIDs(), ocs.FromIDs()...)...,
+			ids...,
 		)
 		if err != nil {
 			return nil, err
 		}
 
 		return &ConnectionFeed{
-			Connections: append(ics, ocs...),
+			Connections: cons,
 			UserMap:     um,
 		}, nil
 	}
@@ -185,6 +214,7 @@ type ConnectionFollowerIDsFunc func(
 	origin uint64,
 ) ([]uint64, error)
 
+// ConnectionFollowerIDs returns the list of ids of users who follow origin.
 func ConnectionFollowerIDs(
 	connections connection.Service,
 ) ConnectionFollowerIDsFunc {
@@ -326,6 +356,8 @@ type ConnectionFriendIDsFunc func(
 	origin uint64,
 ) ([]uint64, error)
 
+// ConnectionFriendIDs returns the list of ids of users who are friends with
+// origin.
 func ConnectionFriendIDs(connections connection.Service) ConnectionFriendIDsFunc {
 	return func(currentApp *app.App, origin uint64) ([]uint64, error) {
 		fs, err := connections.Query(currentApp.Namespace(), connection.QueryOptions{

handler/http/connection.go

@@ -24,7 +24,25 @@ func ConnectionByState(fn core.ConnectionByStateFunc) Handler {
 			state       = extractState(r)
 		)
 
-		feed, err := fn(app, currentUser.ID, state)
+		opts, err := extractConnectionOpts(r)
+		if err != nil {
+			respondError(w, 0, wrapError(ErrBadRequest, err.Error()))
+			return
+		}
+
+		opts.Before, err = extractTimeCursorBefore(r)
+		if err != nil {
+			respondError(w, 0, wrapError(ErrBadRequest, err.Error()))
+			return
+		}
+
+		opts.Limit, err = extractLimit(r)
+		if err != nil {
+			respondError(w, 0, wrapError(ErrBadRequest, err.Error()))
+			return
+		}
+
+		feed, err := fn(app, currentUser.ID, state, opts)
 		if err != nil {
 			respondError(w, 0, err)
 			return
@@ -36,6 +54,12 @@ func ConnectionByState(fn core.ConnectionByStateFunc) Handler {
 		}
 
 		respondJSON(w, http.StatusOK, &payloadConnections{
+			pagination: pagination(
+				r,
+				opts.Limit,
+				connectionCursorAfter(feed.Connections, opts.Limit),
+				connectionCursorBefore(feed.Connections, opts.Limit),
+			),
 			cons:    feed.Connections,
 			origin:  currentUser.ID,
 			userMap: feed.UserMap,
@@ -571,9 +595,10 @@ func (p *payloadConnection) UnmarshalJSON(raw []byte) error {
 }
 
 type payloadConnections struct {
-	cons    connection.List
-	origin  uint64
-	userMap user.Map
+	cons       connection.List
+	origin     uint64
+	pagination *payloadPagination
+	userMap    user.Map
 }
 
 func (p *payloadConnections) MarshalJSON() ([]byte, error) {
@@ -582,11 +607,13 @@ func (p *payloadConnections) MarshalJSON() ([]byte, error) {
 		IncomingCount int                  `json:"incoming_connections_count"`
 		Outgoing      []*payloadConnection `json:"outgoing"`
 		OutgoingCount int                  `json:"outgoing_connections_count"`
+		Pagination    *payloadPagination   `json:"paging"`
 		Users         []*payloadUser       `json:"users"`
 		UsersCount    int                  `json:"users_count"`
 	}{
 		Incoming:   []*payloadConnection{},
 		Outgoing:   []*payloadConnection{},
+		Pagination: p.pagination,
 		Users:      []*payloadUser{},
 		UsersCount: len(p.userMap),
 	}