Add custom pagination template

schema/ent/example/ent/pagination_query.go

@@ -0,0 +1,49 @@
+// Code generated by entc template, DO NOT EDIT.
+
+// Code generated by ent, DO NOT EDIT.
+
+package ent
+
+import (
+	"context"
+
+	"entgo.io/ent/dialect/sql"
+)
+
+// PaginateAfterID paginates User by monotonically increasing "id".
+// It preserves any existing filters/joins applied to the query, fetches up to "limit" items,
+// and returns the next cursor (last ID of this page) and whether a next page exists.
+func (q *UserQuery) PaginateAfterID(ctx context.Context, afterID, limit int) ([]*User, int, bool, error) {
+	if limit <= 0 {
+		limit = 20
+	}
+
+	qq := q.Clone().
+		Order(func(s *sql.Selector) {
+			s.OrderBy(s.C("id"))
+		}).
+		Limit(limit + 1) // fetch one extra to detect "has next"
+
+	if afterID > 0 {
+		qq = qq.Where(func(s *sql.Selector) {
+			s.Where(sql.GT(s.C("id"), afterID))
+		})
+	}
+
+	rows, err := qq.All(ctx)
+	if err != nil {
+		return nil, 0, false, err
+	}
+
+	hasNext := len(rows) > limit
+	if hasNext {
+		rows = rows[:limit]
+	}
+
+	next := 0
+	if len(rows) > 0 {
+		next = rows[len(rows)-1].ID
+	}
+
+	return rows, next, hasNext, nil
+}

schema/ent/example/generate_schema.go

@@ -9,7 +9,16 @@ import (
 
 func main() {
 	log.Println("ersteller start")
-	must(entc.Generate("./schema/ent/example/ent/schema", &gen.Config{}))
+	// Parse our custom pagination template (per-entity Query methods).
+	paginationPath := "schema/ent/pagination_query.tmpl"
+	//paginationTmpl := gen.MustParse(gen.NewTemplate("pagination_query").
+	//	ParseFiles(paginationPath))
+
+	must(entc.Generate(
+		"./schema/ent/example/ent/schema",
+		&gen.Config{},
+		entc.TemplateFiles(paginationPath),
+	))
 }
 
 func must(err error) {

schema/ent/example/start.go

@@ -3,11 +3,9 @@ package main
 import (
 	"context"
 	"ersteller-lib/schema/ent/example/ent"
-	"ersteller-lib/schema/ent/example/ent/user"
 	"log"
 	"time"
 
-	"entgo.io/ent/dialect/sql"
 	_ "github.com/mattn/go-sqlite3"
 )
 
@@ -40,7 +38,8 @@ func main() {
 	//	log.Fatalf("failed updating user: %w", err)
 	//}j
 	//log.Println("user was updated", u)
-	users, nextId, hasNext, err := ListUsersAfterID(ctx, client, 0, 2)
+	query := client.User.Query()
+	users, nextId, hasNext, err := query.PaginateAfterID(ctx, 0, 2)
 	if err != nil {
 		log.Fatalf("failed listing users: %w", err)
 	}
@@ -50,7 +49,7 @@ func main() {
 			log.Println("user", u.ID, u.Email, u.Password)
 		}
 	}
-	users, nextId, hasNext, err = ListUsersAfterID(ctx, client, nextId, 2)
+	users, nextId, hasNext, err = query.PaginateAfterID(ctx, nextId, 2)
 	if err != nil {
 		log.Fatalf("failed listing users: %w", err)
 	}
@@ -62,31 +61,3 @@ func main() {
 	}
 
 }
-
-// afterID is the last ID from the previous page. Use 0 for the first page.
-func ListUsersAfterID(ctx context.Context, client *ent.Client, afterID, limit int) ([]*ent.User, int, bool, error) {
-	q := client.User.Query().
-		Order(user.ByID(sql.OrderAsc())).
-		Limit(limit + 1) // fetch one extra to detect "has next"
-
-	if afterID > 0 {
-		q = q.Where(user.IDGT(afterID))
-	}
-
-	rows, err := q.All(ctx)
-	if err != nil {
-		return nil, -1, false, err
-	}
-
-	hasNext := len(rows) > limit
-	if hasNext {
-		rows = rows[:limit]
-	}
-
-	var next int
-	if len(rows) > 0 {
-		last := rows[len(rows)-1].ID
-		next = last
-	}
-	return rows, next, hasNext, nil
-}

schema/ent/pagination_query.tmpl

@@ -0,0 +1,52 @@
+{{ define "pagination_query" }}
+// Code generated by entc template, DO NOT EDIT.
+
+{{/* A template that adds the functionality for running each client <T> in debug mode */}}
+
+{{/* Add the base header for the generated file */}}
+{{ $pkg := base $.Config.Package }}
+{{ template "header" $ }}
+
+{{ range $n := $.Nodes }}
+
+// PaginateAfterID paginates {{ $n.Name }} by monotonically increasing "id".
+// It preserves any existing filters/joins applied to the query, fetches up to "limit" items,
+// and returns the next cursor (last ID of this page) and whether a next page exists.
+func (q *{{ $n.Name }}Query) PaginateAfterID(ctx context.Context, afterID, limit int) ([]*{{ $n.Name }}, int, bool, error) {
+	if limit <= 0 {
+		limit = 20
+	}
+
+	qq := q.Clone().
+		Order(func(s *sql.Selector) {
+			s.OrderBy(s.C("id"))
+		}).
+		Limit(limit + 1) // fetch one extra to detect "has next"
+
+	if afterID > 0 {
+		qq = qq.Where(func(s *sql.Selector) {
+			s.Where(sql.GT(s.C("id"), afterID))
+		})
+	}
+
+	rows, err := qq.All(ctx)
+	if err != nil {
+		return nil, 0, false, err
+	}
+
+	hasNext := len(rows) > limit
+	if hasNext {
+		rows = rows[:limit]
+	}
+
+	next := 0
+	if len(rows) > 0 {
+		next = rows[len(rows)-1].ID
+	}
+
+	return rows, next, hasNext, nil
+}
+
+{{ end }}
+
+{{ end }}