graph2, changes, rpdata-server: Added changes subscription.

graph2/graph.go

@@ -26,6 +26,10 @@ func (r *rootResolver) Mutation() MutationResolver {
 	return queries.MutationResolver
 }
 
+func (r *rootResolver) Subscription() SubscriptionResolver {
+	return queries.SubscriptionResolver
+}
+
 func (r *rootResolver) Log() LogResolver {
 	return &types.LogResolver
 }

graph2/queries/changes.go

@@ -2,6 +2,7 @@ package queries
 
 import (
 	"context"
+	"errors"
 
 	"git.aiterp.net/rpdata/api/models"
 	"git.aiterp.net/rpdata/api/models/changes"
@@ -12,3 +13,13 @@ import (
 func (r *resolver) Changes(ctx context.Context, filter *changes.Filter) ([]models.Change, error) {
 	return changes.List(filter)
 }
+
+/// Subscriptions
+
+func (r *subscriptionResolver) Changes(ctx context.Context, keys []models.ChangeKey) (<-chan models.Change, error) {
+	if len(keys) == 0 {
+		return nil, errors.New("At least one key is required for a subscription")
+	}
+
+	return changes.Subscribe(ctx, keys, false), nil
+}

graph2/queries/resolver.go

@@ -2,9 +2,13 @@ package queries
 
 type resolver struct{}
 type mutationResolver struct{}
+type subscriptionResolver struct{}
 
 // Resolver has all the queries
 var Resolver resolver
 
 // MutationResolver brings the mutagens.
 var MutationResolver *mutationResolver
+
+// SubscriptionResolver has the real-time magic.
+var SubscriptionResolver *subscriptionResolver

graph2/schema/root.gql

@@ -1,6 +1,7 @@
 schema {
   query: Query
   mutation: Mutation
+  subscription: Subscription
 }
 
 type Query {
@@ -141,6 +142,13 @@ type Mutation {
   editChannel(input: ChannelEditInput!): Channel!
 }
 
+type Subscription {
+  """
+  Changes subscribes to the changes matching the following keys.
+  """
+  changes(keys: [ChangeKeyInput!]!): Change!
+}
+
 # A Date represents a RFC3339 encoded date with up to millisecond precision.
 scalar Date