snapshot of https://github.com/ent/ent.git (master, 2026-09-15; blobs > 131072B omitted)

schema/edge/edge.go

@@ -0,0 +1,276 @@
+// Copyright 2019-present Facebook Inc. All rights reserved.
+// This source code is licensed under the Apache 2.0 license found
+// in the LICENSE file in the root directory of this source tree.
+
+package edge
+
+import (
+	"reflect"
+
+	"entgo.io/ent/schema"
+)
+
+// A Descriptor for edge configuration.
+type Descriptor struct {
+	Tag         string                 // struct tag.
+	Type        string                 // edge type.
+	Name        string                 // edge name.
+	Field       string                 // edge field name (e.g. foreign-key).
+	RefName     string                 // ref name; inverse only.
+	Ref         *Descriptor            // edge reference; to/from of the same type.
+	Through     *struct{ N, T string } // through type and name.
+	Unique      bool                   // unique edge.
+	Inverse     bool                   // inverse edge.
+	Required    bool                   // required on creation.
+	Immutable   bool                   // create only edge.
+	StorageKey  *StorageKey            // optional storage-key configuration.
+	Annotations []schema.Annotation    // edge annotations.
+	Comment     string                 // edge comment.
+}
+
+// To defines an association edge between two vertices.
+func To(name string, t any) *assocBuilder {
+	return &assocBuilder{desc: &Descriptor{Name: name, Type: typ(t)}}
+}
+
+// From represents a reversed-edge between two vertices that has a back-reference to its source edge.
+func From(name string, t any) *inverseBuilder {
+	return &inverseBuilder{desc: &Descriptor{Name: name, Type: typ(t), Inverse: true}}
+}
+
+func typ(t any) string {
+	if rt := reflect.TypeOf(t); rt.NumIn() > 0 {
+		return rt.In(0).Name()
+	}
+	return ""
+}
+
+// assocBuilder is the builder for assoc edges.
+type assocBuilder struct {
+	desc *Descriptor
+}
+
+// Unique sets the edge type to be unique. Basically, it limits the edge to be one of the two:
+// one2one or one2many. one2one applied if the inverse-edge is also unique.
+func (b *assocBuilder) Unique() *assocBuilder {
+	b.desc.Unique = true
+	return b
+}
+
+// Required indicates that this edge is a required field on creation.
+// Unlike fields, edges are optional by default.
+func (b *assocBuilder) Required() *assocBuilder {
+	b.desc.Required = true
+	return b
+}
+
+// Immutable indicates that this edge cannot be updated.
+func (b *assocBuilder) Immutable() *assocBuilder {
+	b.desc.Immutable = true
+	return b
+}
+
+// StructTag sets the struct tag of the assoc edge.
+func (b *assocBuilder) StructTag(s string) *assocBuilder {
+	b.desc.Tag = s
+	return b
+}
+
+// From creates an inverse-edge with the same type.
+func (b *assocBuilder) From(name string) *inverseBuilder {
+	return &inverseBuilder{desc: &Descriptor{Name: name, Type: b.desc.Type, Inverse: true, Ref: b.desc}}
+}
+
+// Field is used to bind an edge (with a foreign-key) to a field in the schema.
+//
+//	field.Int("owner_id").
+//		Optional()
+//
+//	edge.To("owner", User.Type).
+//		Field("owner_id").
+//		Unique(),
+func (b *assocBuilder) Field(f string) *assocBuilder {
+	b.desc.Field = f
+	return b
+}
+
+// Through allows setting an "edge schema" to interact explicitly with M2M edges.
+//
+//	edge.To("friends", User.Type).
+//		Through("friendships", Friendship.Type)
+func (b *assocBuilder) Through(name string, t any) *assocBuilder {
+	b.desc.Through = &struct{ N, T string }{N: name, T: typ(t)}
+	return b
+}
+
+// Comment used to put annotations on the schema.
+func (b *assocBuilder) Comment(c string) *assocBuilder {
+	b.desc.Comment = c
+	return b
+}
+
+// StorageKey sets the storage key of the edge.
+//
+//	edge.To("groups", Group.Type).
+//		StorageKey(edge.Table("user_groups"), edge.Columns("user_id", "group_id"))
+func (b *assocBuilder) StorageKey(opts ...StorageOption) *assocBuilder {
+	if b.desc.StorageKey == nil {
+		b.desc.StorageKey = &StorageKey{}
+	}
+	for i := range opts {
+		opts[i](b.desc.StorageKey)
+	}
+	return b
+}
+
+// Annotations adds a list of annotations to the edge object to be used by
+// codegen extensions.
+//
+//	edge.To("pets", Pet.Type).
+//		Annotations(entgql.Bind())
+func (b *assocBuilder) Annotations(annotations ...schema.Annotation) *assocBuilder {
+	b.desc.Annotations = append(b.desc.Annotations, annotations...)
+	return b
+}
+
+// Descriptor implements the ent.Descriptor interface.
+func (b *assocBuilder) Descriptor() *Descriptor {
+	return b.desc
+}
+
+// inverseBuilder is the builder for inverse edges.
+type inverseBuilder struct {
+	desc *Descriptor
+}
+
+// Ref sets the referenced-edge of this inverse edge.
+func (b *inverseBuilder) Ref(ref string) *inverseBuilder {
+	b.desc.RefName = ref
+	return b
+}
+
+// Unique sets the edge type to be unique. Basically, it limits the edge to be one of the two:
+// one-2-one or one-2-many. one-2-one applied if the inverse-edge is also unique.
+func (b *inverseBuilder) Unique() *inverseBuilder {
+	b.desc.Unique = true
+	return b
+}
+
+// Required indicates that this edge is a required field on creation.
+// Unlike fields, edges are optional by default.
+func (b *inverseBuilder) Required() *inverseBuilder {
+	b.desc.Required = true
+	return b
+}
+
+// Immutable indicates that this edge cannot be updated.
+func (b *inverseBuilder) Immutable() *inverseBuilder {
+	b.desc.Immutable = true
+	return b
+}
+
+// StructTag sets the struct tag of the inverse edge.
+func (b *inverseBuilder) StructTag(s string) *inverseBuilder {
+	b.desc.Tag = s
+	return b
+}
+
+// Comment used to put annotations on the schema.
+func (b *inverseBuilder) Comment(c string) *inverseBuilder {
+	b.desc.Comment = c
+	return b
+}
+
+// Field is used to bind an edge (with a foreign-key) to a field in the schema.
+//
+//	field.Int("owner_id").
+//		Optional()
+//
+//	edge.From("owner", User.Type).
+//		Ref("pets").
+//		Field("owner_id").
+//		Unique(),
+func (b *inverseBuilder) Field(f string) *inverseBuilder {
+	b.desc.Field = f
+	return b
+}
+
+// Through allows setting an "edge schema" to interact explicitly with M2M edges.
+//
+//	edge.From("liked_users", User.Type).
+//		Ref("liked_tweets").
+//		Through("likes", TweetLike.Type)
+func (b *inverseBuilder) Through(name string, t any) *inverseBuilder {
+	b.desc.Through = &struct{ N, T string }{N: name, T: typ(t)}
+	return b
+}
+
+// Annotations adds a list of annotations to the edge object to be used by
+// codegen extensions.
+//
+//	edge.From("owner", User.Type).
+//		Ref("pets").
+//		Unique().
+//		Annotations(entgql.Bind())
+func (b *inverseBuilder) Annotations(annotations ...schema.Annotation) *inverseBuilder {
+	b.desc.Annotations = append(b.desc.Annotations, annotations...)
+	return b
+}
+
+// Descriptor implements the ent.Descriptor interface.
+func (b *inverseBuilder) Descriptor() *Descriptor {
+	return b.desc
+}
+
+// StorageKey holds the configuration for edge storage-key.
+type StorageKey struct {
+	Table   string   // Table or label.
+	Symbols []string // Symbols/names of the foreign-key constraints.
+	Columns []string // Foreign-key columns.
+}
+
+// StorageOption allows for setting the storage configuration using functional options.
+type StorageOption func(*StorageKey)
+
+// Table sets the table name option for M2M edges.
+func Table(name string) StorageOption {
+	return func(key *StorageKey) {
+		key.Table = name
+	}
+}
+
+// Symbol sets the symbol/name of the foreign-key constraint for O2O, O2M and M2O edges.
+// Note that, for M2M edges (2 columns and 2 constraints), use the edge.Symbols option.
+func Symbol(symbol string) StorageOption {
+	return func(key *StorageKey) {
+		key.Symbols = []string{symbol}
+	}
+}
+
+// Symbols sets the symbol/name of the foreign-key constraints for M2M edges.
+// The 1st column defines the name of the "To" edge, and the 2nd defines
+// the name of the "From" edge (inverse edge).
+// Note that, for O2O, O2M and M2O edges, use the edge.Symbol option.
+func Symbols(to, from string) StorageOption {
+	return func(key *StorageKey) {
+		key.Symbols = []string{to, from}
+	}
+}
+
+// Column sets the foreign-key column name option for O2O, O2M and M2O edges.
+// Note that, for M2M edges (2 columns), use the edge.Columns option.
+func Column(name string) StorageOption {
+	return func(key *StorageKey) {
+		key.Columns = []string{name}
+	}
+}
+
+// Columns sets the foreign-key column names option for M2M edges.
+// The 1st column defines the name of the "To" edge, and the 2nd defines
+// the name of the "From" edge (inverse edge).
+// Note that, for O2O, O2M and M2O edges, use the edge.Column option.
+func Columns(to, from string) StorageOption {
+	return func(key *StorageKey) {
+		key.Columns = []string{to, from}
+	}
+}