add change table.

models/change.go

@@ -1,7 +1,9 @@
 package models
 
 import (
+	"fmt"
 	"reflect"
+	"strings"
 	"time"
 )
 
@@ -15,19 +17,23 @@ type Change struct {
 	Keys   []ChangeKey `bson:"keys"`
 	Date   time.Time   `bson:"date"`
 
-	Logs       []*Log       `bson:"logs"`
-	Characters []*Character `bson:"characters"`
-	Channels   []*Channel   `bson:"channels"`
-	Posts      []*Post      `bson:"posts"`
-	Stories    []*Story     `bson:"stories"`
-	Tags       []*Tag       `bson:"tags"`
-	Chapters   []*Chapter   `bson:"chapters"`
-	Comments   []*Comment   `bson:"comments"`
-	Files      []*File      `bson:"files"`
+	ChangeObjectSet
+}
+
+type ChangeObjectSet struct {
+	Logs       []*Log       `bson:"logs" json:"logs,omitempty"`
+	Characters []*Character `bson:"characters" json:"characters,omitempty"`
+	Channels   []*Channel   `bson:"channels" json:"channels,omitempty"`
+	Posts      []*Post      `bson:"posts" json:"posts,omitempty"`
+	Stories    []*Story     `bson:"stories" json:"stories,omitempty"`
+	Tags       []*Tag       `bson:"tags" json:"tags,omitempty"`
+	Chapters   []*Chapter   `bson:"chapters" json:"chapters,omitempty"`
+	Comments   []*Comment   `bson:"comments" json:"comments,omitempty"`
+	Files      []*File      `bson:"files" json:"files,omitempty"`
 }
 
 // AddObject adds the model into the appropriate array.
-func (change *Change) AddObject(object interface{}) bool {
+func (change *ChangeObjectSet) AddObject(object interface{}) bool {
 	if v := reflect.ValueOf(object); v.Kind() == reflect.Struct {
 		ptr := reflect.PtrTo(v.Type())
 		ptrValue := reflect.New(ptr.Elem())
@@ -174,10 +180,32 @@ type ChangeKey struct {
 	ID    string      `bson:"id"`
 }
 
+func (ck *ChangeKey) String() string {
+	return ck.Model.String() + ":" + ck.ID
+}
+
+func (ck *ChangeKey) Decode(str string) error {
+	split := strings.Split(str, ":")
+	if len(split) != 2 {
+		return fmt.Errorf("invalid change key: %s", str)
+	}
+
+	model := ChangeModel(split[0])
+	if !model.IsValid() {
+		return fmt.Errorf("invalid change key model: %s", model)
+	}
+
+	ck.Model = model
+	ck.ID = split[1]
+
+	return nil
+}
+
 // ChangeFilter is a filter for listing changes.
 type ChangeFilter struct {
 	Keys         []ChangeKey
 	EarliestDate *time.Time
+	LatestDate   *time.Time
 	Author       *string
 	Limit        *int
 }