added docs for router context (ThreeDotsLabs#167)

roblaszczak · m110 · commit 791f4c70ea6c · 2019-12-08T22:09:14.000+01:00
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/router_context.go b/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/router_context_test.go b/message/router_context_test.go

Original file line number	Diff line number	Diff line change
`@@ -22,22 +22,29 @@ func valFromCtx(ctx context.Context, key ctxKey) string {`
`22`	`22`	`return val`
`23`	`23`	`}`
`24`	`24`
	`25`	`+// HandlerNameFromCtx returns the name of the message handler in the router that consumed the message.`
`25`	`26`	`func HandlerNameFromCtx(ctx context.Context) string {`
`26`	`27`	`return valFromCtx(ctx, handlerNameKey)`
`27`	`28`	`}`
`28`	`29`
	`30`	`+// PublisherNameFromCtx returns the name of the message publisher type that published the message in the router.`
	`31`	+// For example, for Kafka it will be `kafka.Publisher`.
`29`	`32`	`func PublisherNameFromCtx(ctx context.Context) string {`
`30`	`33`	`return valFromCtx(ctx, publisherNameKey)`
`31`	`34`	`}`
`32`	`35`
	`36`	`+// SubscriberNameFromCtx returns the name of the message subscriber type that subscribed to the message in the router.`
	`37`	+// For example, for Kafka it will be `kafka.Subscriber`.
`33`	`38`	`func SubscriberNameFromCtx(ctx context.Context) string {`
`34`	`39`	`return valFromCtx(ctx, subscriberNameKey)`
`35`	`40`	`}`
`36`	`41`
	`42`	`+// SubscribeTopicFromCtx returns the topic from which message was received in the router.`
`37`	`43`	`func SubscribeTopicFromCtx(ctx context.Context) string {`
`38`	`44`	`return valFromCtx(ctx, subscribeTopicKey)`
`39`	`45`	`}`
`40`	`46`
	`47`	`+// PublishTopicFromCtx returns the topic to which message will be published by the router.`
`41`	`48`	`func PublishTopicFromCtx(ctx context.Context) string {`
`42`	`49`	`return valFromCtx(ctx, publishTopicKey)`
`43`	`50`	`}`