Add BoolFlag for rawdatastore.

service/rawdatastore/properties.go

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package rawdatastore
 
 import (
         "errors"
         "fmt"
         "math"
@@ skipping 329 matching lines @@
         //   type MyStruct struct {
         //     CoolField int64 `gae:"$id,1"`
         //   }
         //   val, err := helper.GetPLS(&MyStruct{}).GetMeta("id")
         //   // val == 1
         //   // err == nil
         //
         //   val, err := helper.GetPLS(&MyStruct{10}).GetMeta("id")
         //   // val == 10
         //   // err == nil
+        //
+        // Struct fields of type Toggle (which is an Auto/On/Off) allow you to
+        // specify a value of 'true' or 'false' for the default value of the struct
+        // tag, and GetMeta will return the combined value as a regular boolean true
+        // or false value. If a field is Toggle, a <value> MUST be specified.
+        //
+        // Example:
+        //   type MyStruct struct {
+        //     TFlag Toggle `gae:"$flag1,true"`  // defaults to true
+        //     FFlag Toggle `gae:"$flag2,false"` // defaults to false
+        //     // BadFlag  Toggle `gae:"$flag3"` // ILLEGAL
+        //   }
         GetMeta(key string) (interface{}, error)
 
         // SetMeta allows you to set the current value of the meta-keyed field.
         SetMeta(key string, val interface{}) error
 
         // Problem indicates that this PLS has a fatal problem. Usually this is
         // set when the underlying struct has recursion, invalid field types, nested
         // slices, etc.
         Problem() error
 }
@@ skipping 70 matching lines @@
                 return err
         }
         pm["$"+key] = []Property{prop}
         return nil
 }
 
 // Problem implements PropertyLoadSaver.Problem. It ALWAYS returns nil.
 func (pm PropertyMap) Problem() error {
         return nil
 }