added docs for router context (#167)

ThreeDotsLabs · Dec 8, 2019 · 791f4c7 · 791f4c7
1 parent c9213ee
commit 791f4c7
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Showing 5 changed files with 18 additions and 2 deletions.
diff --git a/docs/build.sh b/docs/build.sh
@@ -38,6 +38,7 @@ else
         "message/message.go"
         "message/pubsub.go"
         "message/router.go"
+        "message/router_context.go"
         "pubsub/gochannel/pubsub.go"
 
         "components/cqrs/command_bus.go"

diff --git a/docs/content/docs/messages-router.md b/docs/content/docs/messages-router.md
@@ -104,3 +104,11 @@ A full list of standard middlewares can be found in [Middlewares]({{< ref "/docs
 {{% /render-md %}}
 
 A full list of standard plugins can be found in [message/router/plugin](https://github.com/ThreeDotsLabs/watermill/tree/master/message/router/plugin).
+
+### Context
+
+Each message received by handler holds some useful values in the `context`:
+
+{{% render-md %}}
+{{% load-snippet-partial file="src-link/message/router_context.go" first_line_contains="// HandlerNameFromCtx" last_line_contains="func PublishTopicFromCtx" padding_after="2" %}}
+{{% /render-md %}}
diff --git a/docs/content/pubsubs/kafka.md b/docs/content/pubsubs/kafka.md
@@ -40,7 +40,7 @@ When `nil` is passed, default config is used (`DefaultSaramaSubscriberConfig`).
 
 ##### Publisher
 {{% render-md %}}
-{{% load-snippet-partial file="src-link/watermill-kafka/pkg/kafka/publisher.go" first_line_contains="// NewPublisher" last_line_contains="(message.Publisher, error)" padding_after="0" %}}
+{{% load-snippet-partial file="src-link/watermill-kafka/pkg/kafka/publisher.go" first_line_contains="// NewPublisher" last_line_contains="(*Publisher, error)" padding_after="0" %}}
 
 Example:
 {{% load-snippet-partial file="src-link/_examples/pubsubs/kafka/main.go" first_line_contains="saramaSubscriberConfig :=" last_line_contains="panic(err)" padding_after="1" %}}
@@ -49,7 +49,7 @@ Example:
 
 ##### Subscriber
 {{% render-md %}}
-{{% load-snippet-partial file="src-link/watermill-kafka/pkg/kafka/subscriber.go" first_line_contains="// NewSubscriber" last_line_contains="(message.Subscriber, error)" padding_after="0" %}}
+{{% load-snippet-partial file="src-link/watermill-kafka/pkg/kafka/subscriber.go" first_line_contains="// NewSubscriber" last_line_contains="(*Subscriber, error)" padding_after="0" %}}
 
 Example:
 {{% load-snippet-partial file="src-link/_examples/pubsubs/kafka/main.go" first_line_contains="publisher, err := kafka.NewPublisher" last_line_contains="panic(err)" padding_after="1" %}}

diff --git a/message/context.go → message/router_context.go b/message/context.go → message/router_context.go
@@ -22,22 +22,29 @@ func valFromCtx(ctx context.Context, key ctxKey) string {
 	return val
 }
 
+// HandlerNameFromCtx returns the name of the message handler in the router that consumed the message.
 func HandlerNameFromCtx(ctx context.Context) string {
 	return valFromCtx(ctx, handlerNameKey)
 }
 
+// PublisherNameFromCtx returns the name of the message publisher type that published the message in the router.
+// For example, for Kafka it will be `kafka.Publisher`.
 func PublisherNameFromCtx(ctx context.Context) string {
 	return valFromCtx(ctx, publisherNameKey)
 }
 
+// SubscriberNameFromCtx returns the name of the message subscriber type that subscribed to the message in the router.
+// For example, for Kafka it will be `kafka.Subscriber`.
 func SubscriberNameFromCtx(ctx context.Context) string {
 	return valFromCtx(ctx, subscriberNameKey)
 }
 
+// SubscribeTopicFromCtx returns the topic from which message was received in the router.
 func SubscribeTopicFromCtx(ctx context.Context) string {
 	return valFromCtx(ctx, subscribeTopicKey)
 }
 
+// PublishTopicFromCtx returns the topic to which message will be published by the router.
 func PublishTopicFromCtx(ctx context.Context) string {
 	return valFromCtx(ctx, publishTopicKey)
 }
diff --git a/message/context_test.go → message/router_context_test.go b/message/context_test.go → message/router_context_test.go