updating references to activity.Register, uppercase for component/con…

…cept names (#306)

activity/doc.go

@@ -23,17 +23,17 @@
 // THE SOFTWARE.
 
 /*
-Package activity contains functions and types used to implement Temporal activities.
+Package activity contains functions and types used to implement Temporal Activities.
 
-The activity is an implementation of a task to be performed as part of a larger workflow. There is no limitation of
-what an activity can do. In the context of a workflow, it is in the activities where all operations that affect the
+An Activity is an implementation of a task to be performed as part of a larger Workflow. There is no limitation of
+what an Activity can do. In the context of a Workflow, it is in the Activities where all operations that affect the
 desired results must be implemented.
 
 Overview
 
 Temporal Go SDK does all the heavy lifting of handling the async communication between the Temporal
-managed service and the worker running the activity. As such, the implementation of the activity can, for the most
-part, focus on the business logic. The sample code below shows the implementation of a simple activity that accepts a
+managed service and the Worker running the Activity. As such, the implementation of the Activity can, for the most
+part, focus on the business logic. The sample code below shows the implementation of a simple Activity that accepts a
 string parameter, appends a word to it and then returns the result.
 
 	import (
@@ -42,10 +42,6 @@ string parameter, appends a word to it and then returns the result.
 		"go.temporal.io/sdk/activity"
 	)
 
-	func init() {
-		activity.Register(SimpleActivity)
-	}
-
 	func SimpleActivity(ctx context.Context, value string) (string, error) {
 		activity.GetLogger(ctx).Info("SimpleActivity called.", "Value", value)
 		return "Processed: ” + value, nil
@@ -55,37 +51,37 @@ The following sections explore the elements of the above code.
 
 Declaration
 
-In the Temporal programing model, an activity is implemented with a function. The function declaration specifies the
-parameters the activity accepts as well as any values it might return. An activity function can take zero or many
-activity specific parameters and can return one or two values. It must always at least return an error value. The
-activity function can accept as parameters and return as results any serializable type.
+In the Temporal programing model, an Activity is implemented with a function. The function declaration specifies the
+parameters the Activity accepts as well as any values it might return. An Activity function can take zero or many
+Activity specific parameters and can return one or two values. It must always at least return an error value. The
+Activity function can accept as parameters and return as results any serializable type.
 
     func SimpleActivity(ctx context.Context, value string) (string, error)
 
 The first parameter to the function is context.Context. This is an optional parameter and can be omitted. This
 parameter is the standard Go context.
 
-The second string parameter is a custom activity-specific parameter that can be used to pass in data into the activity
-on start. An activity can have one or more such parameters. All parameters to an activity function must be
+The second string parameter is a custom Activity-specific parameter that can be used to pass in data into the Activity
+on start. An Activity can have one or more such parameters. All parameters to an Activity function must be
 serializable, which essentially means that params can’t be channels, functions, variadic, or unsafe pointer.
 
-The activity declares two return values: (string, error). The string return value is used to return the result of the
-activity. The error return value is used to indicate an error was encountered during execution.
+The Activity declares two return values: (string, error). The string return value is used to return the result of the
+Activity. The error return value is used to indicate an error was encountered during execution.
 
 Implementation
 
-There is nothing special about activity code. You can write activity implementation code the same way you would any
+There is nothing special about Activity code. You can write Activity implementation code the same way you would any
 other Go service code. You can use the usual loggers and metrics collectors. You can use the standard Go concurrency
 constructs.
 
-Failing the activity
+Failing the Activity
 
-To mark an activity as failed, all that needs to happen is for the activity function to return an error via the error
+To mark an Activity as failed, all that needs to happen is for the Activity function to return an error via the error
 return value.
 
 Activity Heartbeating
 
-For long running activities, Temporal provides an API for the activity code to report both liveness and progress back to
+For long running Activities, Temporal provides an API for the Activity code to report both liveness and progress back to
 the Temporal managed service.
 
     progress := 0
@@ -97,10 +93,10 @@ the Temporal managed service.
         progress++
     }
 
-When the activity times out due to a missed heartbeat, the last value of the details (progress in the above sample) is
+When the Activity times out due to a missed heartbeat, the last value of the details (progress in the above sample) is
 returned from the workflow.ExecuteActivity function as the details field of TimeoutError with TimeoutType_HEARTBEAT.
 
-It is also possible to heartbeat an activity from an external source:
+It is also possible to heartbeat an Activity from an external source:
 
     // instantiate a Temporal service Client
     client.Client client = client.NewClient(...)
@@ -109,21 +105,21 @@ It is also possible to heartbeat an activity from an external source:
     err := client.RecordActivityHeartbeat(ctx, taskToken, details)
 
 It expects an additional parameter, "taskToken", which is the value of the binary "TaskToken" field of the
-"ActivityInfo" struct retrieved inside the activity (GetActivityInfo(ctx).TaskToken). "details" is the serializable
+"ActivityInfo" struct retrieved inside the Activity (GetActivityInfo(ctx).TaskToken). "details" is the serializable
 payload containing progress information.
 
 Activity Cancellation
 
-When an activity is canceled (or its workflow execution is completed or failed) the context passed into its function
-is canceled which sets its Done channel’s closed state. So an activity can use that to perform any necessary cleanup
-and abort its execution. Currently cancellation is delivered only to activities that call RecordHeartbeat.
+When an Activity is canceled (or its Workflow execution is completed or failed) the context passed into its function
+is canceled which sets its Done channel’s closed state. So an Activity can use that to perform any necessary cleanup
+and abort its execution. Currently cancellation is delivered only to Activities that call RecordHeartbeat.
 
 Async/Manual Activity Completion
 
-In certain scenarios completing an activity upon completion of its function is not possible or desirable.
+In certain scenarios completing an Activity upon completion of its function is not possible or desirable.
 
-One example would be the UberEATS order processing workflow that gets kicked off once an eater pushes the “Place Order”
-button. Here is how that workflow could be implemented using Temporal and the “async activity completion”:
+One example would be the UberEATS order processing Workflow that gets kicked off once an eater pushes the “Place Order”
+button. Here is how that Workflow could be implemented using Temporal and the “async Activity completion”:
 
   - Activity 1: send order to restaurant
   - Activity 2: wait for restaurant to accept order
@@ -133,46 +129,46 @@ button. Here is how that workflow could be implemented using Temporal and the 
   - Activity 6: complete order
 
 Activities 2 & 4 in the above flow require someone in the restaurant to push a button in the Uber app to complete the
-activity. The activities could be implemented with some sort of polling mechanism. However, they can be implemented
-much simpler and much less resource intensive as a Temporal activity that is completed asynchronously.
+Activity. The Activities could be implemented with some sort of polling mechanism. However, they can be implemented
+much simpler and much less resource intensive as a Temporal Activity that is completed asynchronously.
 
-There are 2 parts to implementing an asynchronously completed activity. The first part is for the activity to provide
+There are 2 parts to implementing an asynchronously completed Activity. The first part is for the Activity to provide
 the information necessary to be able to be completed from an external system and notify the Temporal service that it is
 waiting for that outside callback:
 
-    // retrieve activity information needed to complete activity asynchronously
+    // retrieve Activity information needed to complete Activity asynchronously
     activityInfo := activity.GetInfo(ctx)
     taskToken := activityInfo.TaskToken
 
-    // send the taskToken to external service that will complete the activity
+    // send the taskToken to external service that will complete the Activity
     ...
 
-    // return from activity function indicating the Temporal should wait for an async completion message
+    // return from Activity function indicating the Temporal should wait for an async completion message
     return "", activity.ErrResultPending
 
-The second part is then for the external service to call the Temporal service to complete the activity. To complete the
-activity successfully you would do the following:
+The second part is then for the external service to call the Temporal service to complete the Activity. To complete the
+Activity successfully you would do the following:
 
     // instantiate a Temporal service Client
-    // the same client can be used complete or fail any number of activities
+    // the same client can be used complete or fail any number of Activities
     client.Client client = client.NewClient(...)
 
-    // complete the activity
+    // complete the Activity
     client.CompleteActivity(taskToken, result, nil)
 
-And here is how you would fail the activity:
+And here is how you would fail the Activity:
 
-    // fail the activity
+    // fail the Activity
     client.CompleteActivity(taskToken, nil, err)
 
 The parameters of the CompleteActivity function are:
 
   - taskToken: This is the value of the binary “TaskToken” field of the
-    “ActivityInfo” struct retrieved inside the activity.
-  - result: This is the return value that should be recorded for the activity.
+    “ActivityInfo” struct retrieved inside the Activity.
+  - result: This is the return value that should be recorded for the Activity.
 	The type of this value needs to match the type of the return value
-	declared by the activity function.
-  - err: The error code to return if the activity should terminate with an
+	declared by the Activity function.
+  - err: The error code to return if the Activity should terminate with an
     error.
 
 If error is not null the value of the result field is ignored.
@@ -181,14 +177,22 @@ For a full example of implementing this pattern see the Expense sample.
 
 Registration
 
-In order to for some workflow execution to be able to invoke an activity type, the worker process needs to be aware of
-all the implementations it has access to. An activity is registered with the following call:
-
-    activity.Register(SimpleActivity)
-
-This call essentially creates an in-memory mapping inside the worker process between the fully qualified function name
-and the implementation. Unlike in Amazon SWF, workflow and activity types are not registered with the managed service.
-If the worker receives a request to start an activity execution for an activity type it does not know it will fail that
+In order to for some Workflow execution to be able to invoke an Activity type, the Worker process needs to be aware of
+all the implementations it has access to. To do that, create a Worker and register the Activity like so:
+
+```
+  c, err := client.NewClient(client.Options{})
+  if err != nil {
+    log.Fatalln("unable to create Temporal client", err)
+  }
+  defer c.Close()
+  w := worker.New(c, "SomeTaskQueue", worker.Options{})
+  w.RegisterActivity(SomeActivityFunction)
+```
+
+This call essentially creates an in-memory mapping inside the Worker process between the fully qualified function name
+and the implementation. Unlike in Amazon SWF, Workflow and Activity types are not registered with the managed service.
+If the Worker receives a request to start an Activity execution for an Activity type it does not know it will fail that
 request.
 
 */

worker/worker.go

@@ -118,7 +118,6 @@ type (
 		// Serialization of all primitive types, structures is supported ... except channels, functions, variadic, unsafe pointer.
 		// This method panics if activityFunc doesn't comply with the expected format or an activity with the same
 		// type name is registered more than once.
-		// For global registration consider activity.Register
 		RegisterActivity(a interface{})
 
 		// RegisterActivityWithOptions registers the activity function or struct pointer with options.