Method ReorderModels

migrator/migrator.go:919–1020

ReorderModels reorder models according to constraint dependencies

(values []interface{}, autoAdd bool)

// ReorderModels reorder models according to constraint dependencies
func (m Migrator) ReorderModels(values []interface{}, autoAdd bool) (results []interface{}) {
	type Dependency struct {
		*gorm.Statement
		Depends []*schema.Schema
	}

	var (
		modelNames, orderedModelNames []string
		orderedModelNamesMap          = map[string]bool{}
		parsedSchemas                 = map[*schema.Schema]bool{}
		valuesMap                     = map[string]Dependency{}
		insertIntoOrderedList         func(name string)
		parseDependence               func(value interface{}, addToList bool)
	)

	parseDependence = func(value interface{}, addToList bool) {
		dep := Dependency{
			Statement: &gorm.Statement{DB: m.DB, Dest: value},
		}
		beDependedOn := map[*schema.Schema]bool{}
		// support for special table name
		if err := dep.ParseWithSpecialTableName(value, m.DB.Statement.Table); err != nil {
			m.DB.Logger.Error(context.Background(), "failed to parse value %#v, got error %v", value, err)
		}
		if _, ok := parsedSchemas[dep.Statement.Schema]; ok {
			return
		}
		parsedSchemas[dep.Statement.Schema] = true

		if !m.DB.IgnoreRelationshipsWhenMigrating {
			for _, rel := range dep.Schema.Relationships.Relations {
				if rel.Field.IgnoreMigration {
					continue
				}
				if c := rel.ParseConstraint(); c != nil && c.Schema == dep.Statement.Schema && c.Schema != c.ReferenceSchema {
					dep.Depends = append(dep.Depends, c.ReferenceSchema)
				}

				if rel.Type == schema.HasOne || rel.Type == schema.HasMany {
					beDependedOn[rel.FieldSchema] = true
				}

				if rel.JoinTable != nil {
					// append join value
					defer func(rel *schema.Relationship, joinValue interface{}) {
						if !beDependedOn[rel.FieldSchema] {
							dep.Depends = append(dep.Depends, rel.FieldSchema)
						} else {
							fieldValue := reflect.New(rel.FieldSchema.ModelType).Interface()
							parseDependence(fieldValue, autoAdd)
						}
						parseDependence(joinValue, autoAdd)
					}(rel, reflect.New(rel.JoinTable.ModelType).Interface())
				}
			}
		}

		valuesMap[dep.Schema.Table] = dep