refactor: resolve project labels at runtime (resolve #227)

migrations/20210411_drop_migrations_table.go

@@ -11,7 +11,7 @@ func init() {
 	f := migrationFunc{
 		name: name,
 		f: func(db *gorm.DB, cfg *config.Config) error {
-			if err := db.Migrator().DropTable("gorp_migrations"); err != nil {
+			if err := db.Migrator().DropTable("gorp_migrations"); err == nil {
 				logbuch.Info("dropped table 'gorp_migrations'")
 			}
 			return nil

migrations/20210806_remove_persisted_project_labels.go

@@ -0,0 +1,49 @@
+package migrations
+
+import (
+	"github.com/emvi/logbuch"
+	"github.com/muety/wakapi/config"
+	"github.com/muety/wakapi/models"
+	"gorm.io/gorm"
+)
+
+func init() {
+	const name = "20210806-remove_persisted_project_labels"
+	f := migrationFunc{
+		name: name,
+		f: func(db *gorm.DB, cfg *config.Config) error {
+			condition := "key = ?"
+			if cfg.Db.Dialect == config.SQLDialectMysql {
+				condition = "`key` = ?"
+			}
+
+			lookupResult := db.Where(condition, name).First(&models.KeyStringValue{})
+			if lookupResult.Error == nil && lookupResult.RowsAffected > 0 {
+				logbuch.Info("no need to migrate '%s'", name)
+				return nil
+			}
+
+			rawDb, err := db.DB()
+			if err != nil {
+				logbuch.Error("failed to retrieve raw sql db instance")
+				return err
+			}
+			if _, err := rawDb.Exec("delete from summary_items where type = ?", models.SummaryLabel); err != nil {
+				logbuch.Error("failed to delete project label summary items")
+				return err
+			}
+			logbuch.Info("successfully deleted project label summary items")
+
+			if err := db.Create(&models.KeyStringValue{
+				Key:   name,
+				Value: "done",
+			}).Error; err != nil {
+				return err
+			}
+
+			return nil
+		},
+	}
+
+	registerPostMigration(f)
+}

models/summary.go

@@ -30,7 +30,7 @@ type Summary struct {
 	Editors          SummaryItems `json:"editors" gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE"`
 	OperatingSystems SummaryItems `json:"operating_systems" gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE"`
 	Machines         SummaryItems `json:"machines" gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE"`
-	Labels           SummaryItems `json:"labels" gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE"`
+	Labels           SummaryItems `json:"labels" gorm:"-"` // labels are not persisted, but calculated at runtime, i.e. when summary is retrieved
 }
 
 type SummaryItems []*SummaryItem

repositories/summary.go

@@ -23,7 +23,6 @@ func (r *SummaryRepository) GetAll() ([]*models.Summary, error) {
 		Preload("Editors", "type = ?", models.SummaryEditor).
 		Preload("OperatingSystems", "type = ?", models.SummaryOS).
 		Preload("Machines", "type = ?", models.SummaryMachine).
-		Preload("Labels", "type = ?", models.SummaryLabel).
 		Find(&summaries).Error; err != nil {
 		return nil, err
 	}
@@ -49,7 +48,6 @@ func (r *SummaryRepository) GetByUserWithin(user *models.User, from, to time.Tim
 		Preload("Editors", "type = ?", models.SummaryEditor).
 		Preload("OperatingSystems", "type = ?", models.SummaryOS).
 		Preload("Machines", "type = ?", models.SummaryMachine).
-		Preload("Labels", "type = ?", models.SummaryLabel).
 		Find(&summaries).Error; err != nil {
 		return nil, err
 	}

services/summary.go

@@ -94,6 +94,7 @@ func (srv *SummaryService) Retrieve(from, to time.Time, user *models.User) (*mod
 	if err != nil {
 		return nil, err
 	}
+	summary = srv.withProjectLabels(summary)
 
 	return summary.Sorted(), nil
 }

views/settings.tpl.html

@@ -212,7 +212,7 @@
             <div class="w-full" id="project-labels">
                 <div class="text-gray-300 text-sm mb-4 mt-6">
                     You can assign labels (aka. tags) to projects to group them together, e.g. by <span class="inline-block mb-1 text-gray-500 italic">private</span> and <span
-                        class="inline-block mb-1 text-gray-500 italic">work</span>. Please note that labels are only applied to new data, not to existing summaries in retrospect. To label historic data, you will need to clear and regenerate your summaries (see down below).
+                        class="inline-block mb-1 text-gray-500 italic">work</span>.
                 </div>
 
                 {{ if .Labels }}