Implement the client part for the logger worker.

state/api/logger/logger.go

+// Copyright 2013 Canonical Ltd.
+// Licensed under the AGPLv3, see LICENCE file for details.
+
+package logger
+
+import (
+        "fmt"
+
+        "launchpad.net/juju-core/state/api/common"
+        "launchpad.net/juju-core/state/api/params"
+        "launchpad.net/juju-core/state/api/watcher"
+)
+
+// State provides access to an logger worker's view of the state.
+type State struct {
+        caller common.Caller
+}
+
+// NewState returns a version of the state that provides functionality
+// required by the logger worker.
+func NewState(caller common.Caller) *State {
+        return &State{caller}
+}
+
+func (st *State) LoggingConfig(tag string) (string, error) {

[wallyworld, 2013/09/13 02:50:33]

Doc string please. At first glance, I don't know what tag is.

+        var results params.StringResults
+        args := params.Entities{
+                Entities: []params.Entity{{Tag: tag}},
+        }
+        err := st.caller.Call("Logger", "", "LoggingConfig", args, &results)
+        if err != nil {
+                // TODO: Not directly tested
+                return "", err
+        }
+        if len(results.Results) != 1 {
+                // TODO: Not directly tested
+                return "", fmt.Errorf("expected one result, got %d", len(results.Results))
+        }
+        result := results.Results[0]
+        if err := result.Error; err != nil {
+                return "", err
+        }
+        return result.Result, nil
+}
+
+func (st *State) WatchLoggingConfig(agentTag string) (watcher.NotifyWatcher, error) {

[wallyworld, 2013/09/13 02:50:33]

Doc string again. Also, why agentTag here and tag above?

+        var results params.NotifyWatchResults
+        args := params.Entities{
+                Entities: []params.Entity{{Tag: agentTag}},
+        }
+        err := st.caller.Call("Logger", "", "WatchLoggingConfig", args, &results)
+        if err != nil {
+                // TODO: Not directly tested
+                return nil, err
+        }
+        if len(results.Results) != 1 {
+                // TODO: Not directly tested
+                return nil, fmt.Errorf("expected one result, got %d", len(results.Results))
+        }
+        result := results.Results[0]
+        if result.Error != nil {
+                //  TODO: Not directly tested
+                return nil, result.Error
+        }
+        w := watcher.NewNotifyWatcher(st.caller, result)
+        return w, nil
+}