Refactor pagination system with flexible ordering support
This commit overhauls the pagination system to support flexible ordering beyond the default created_at timestamp: - Change CursorKey from fixed byte array to structured object with ID and Value - Add OrderField and OrderDirection types to support different sorting options - Update SQLFragment to dynamically generate SQL based on field and direction - Modify cursor navigation logic to consider custom ordering - Simplify Position type to use string constants instead of numeric values - Update Page struct to include reference to Cursor These changes allow paginated queries to be ordered by different fields (created_at, updated_at, name) in either ascending or descending order while maintaining consistent cursor-based pagination behavior. Signed-off-by: gearnode <bryan@frimin.fr>
This commit is contained in:
gearnode
@@ -15,80 +15,80 @@
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package page
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import (
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"fmt"
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"github.com/jackc/pgx/v5"
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)
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type (
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Cursor struct {
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Size int
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Key *CursorKey
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Position Position
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Key *CursorKey
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OrderBy OrderBy
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}
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Position int8
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Position string
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OrderBy struct {
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Field OrderField
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Direction OrderDirection
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}
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)
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const (
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DefaultCursorSize = 25
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Tail Position = iota
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Head
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Tail Position = "TAIL"
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Head Position = "HEAD"
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)
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func (p Position) ToDirection() string {
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switch p {
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case Tail:
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return "ASC"
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case Head:
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return "DESC"
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default:
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panic(fmt.Errorf("unknown direction: %d", p))
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}
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}
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func NewCursor(size int, from *CursorKey, pos Position) *Cursor {
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func NewCursor(size int, from *CursorKey, pos Position, orderBy *OrderBy) *Cursor {
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if size == 0 {
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size = DefaultCursorSize
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}
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if orderBy == nil {
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orderBy = &OrderBy{
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Field: OrderFieldCreatedAt,
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Direction: OrderDirectionDesc,
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}
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}
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return &Cursor{
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Size: size,
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Key: from,
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Position: pos,
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OrderBy: *orderBy,
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}
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}
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func (c *Cursor) SQLFragment() string {
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return `
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CASE
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WHEN @cursor_order = 'DESC' AND @cursor_from_id::TEXT IS NOT NULL THEN (
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(created_at <= @cursor_from_ts) AND NOT (created_at = @cursor_from_ts AND id > @cursor_from_id)
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)
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WHEN @cursor_order = 'ASC' AND @cursor_from_id::TEXT IS NOT NULL THEN (
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(created_at >= @cursor_from_ts) AND NOT (created_at = @cursor_from_ts AND id < @cursor_from_id)
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)
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ELSE TRUE
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END
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ORDER BY
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CASE
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WHEN @cursor_order = 'ASC' THEN created_at
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END ASC,
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CASE
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WHEN @cursor_order = 'ASC' THEN id
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END ASC,
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CASE
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WHEN @cursor_order = 'DESC' THEN created_at
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END DESC,
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CASE
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WHEN @cursor_order = 'DESC' THEN id
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END DESC
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LIMIT @cursor_limit
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`
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fieldName := c.OrderBy.Field.Column()
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var orderDirection string
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switch {
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case c.OrderBy.Direction == OrderDirectionAsc && c.Position == Head:
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orderDirection = "ASC"
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case c.OrderBy.Direction == OrderDirectionDesc && c.Position == Head:
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orderDirection = "DESC"
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case c.OrderBy.Direction == OrderDirectionAsc && c.Position == Tail:
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orderDirection = "DESC"
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case c.OrderBy.Direction == OrderDirectionDesc && c.Position == Tail:
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orderDirection = "ASC"
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}
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whereClause := "TRUE"
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if c.Key != nil && orderDirection == "DESC" {
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whereClause = "(" + fieldName + " <= @cursor_field_value) AND NOT (" + fieldName + " = @cursor_field_value AND id > @cursor_id)"
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} else if c.Key != nil && orderDirection == "ASC" {
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whereClause = "(" + fieldName + " >= @cursor_field_value) AND NOT (" + fieldName + " = @cursor_field_value AND id < @cursor_id)"
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}
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orderByClause := fieldName + " " + orderDirection + ", id " + orderDirection
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return whereClause + " ORDER BY " + orderByClause + " LIMIT @cursor_limit"
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}
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func (c *Cursor) SQLArguments() pgx.StrictNamedArgs {
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func (c *Cursor) SQLArguments() pgx.NamedArgs {
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var size = c.Size
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if c.Key == nil {
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size += 1
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@@ -96,16 +96,13 @@ func (c *Cursor) SQLArguments() pgx.StrictNamedArgs {
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size += 2
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}
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arguments := pgx.StrictNamedArgs{
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"cursor_order": c.Position.ToDirection(),
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"cursor_limit": size,
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"cursor_from_id": nil,
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"cursor_from_ts": nil,
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arguments := pgx.NamedArgs{
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"cursor_limit": size,
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}
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if c.Key != nil {
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arguments["cursor_from_id"] = c.Key.ID()
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arguments["cursor_from_ts"] = c.Key.Timestamp()
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arguments["cursor_id"] = c.Key.ID
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arguments["cursor_field_value"] = c.Key.Value
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}
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return arguments
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@@ -16,16 +16,16 @@ package page
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import (
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"encoding/base64"
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"encoding/binary"
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"encoding/json"
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"errors"
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"time"
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"github.com/getprobo/probo/pkg/gid"
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)
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type (
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CursorKey [byteLength]byte
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)
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type CursorKey struct {
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ID gid.GID
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Value any
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}
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var (
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CursorKeyNil CursorKey
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@@ -33,63 +33,64 @@ var (
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ErrInvalidFormat = errors.New("invalid format")
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)
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const (
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byteLength = 24
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)
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func ParseCursorKey(s string) (CursorKey, error) {
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b, err := base64.RawURLEncoding.DecodeString(s)
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data, err := base64.RawURLEncoding.DecodeString(s)
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if err != nil {
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return CursorKeyNil, ErrInvalidFormat
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}
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ck, err := CursorKeyFromBytes(b)
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var arr []json.RawMessage
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if err := json.Unmarshal(data, &arr); err != nil {
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return CursorKeyNil, ErrInvalidFormat
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}
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if len(arr) != 2 {
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return CursorKeyNil, ErrInvalidFormat
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}
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var idStr string
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if err := json.Unmarshal(arr[0], &idStr); err != nil {
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return CursorKeyNil, ErrInvalidFormat
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}
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id, err := gid.ParseGID(idStr)
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if err != nil {
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return CursorKeyNil, ErrInvalidFormat
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}
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return ck, nil
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}
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func CursorKeyFromBytes(b []byte) (CursorKey, error) {
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var ck CursorKey
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if len(b) != byteLength {
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var value any
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if err := json.Unmarshal(arr[1], &value); err != nil {
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return CursorKeyNil, ErrInvalidFormat
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}
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copy(ck[:], b)
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return ck, nil
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return CursorKey{
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ID: id,
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Value: value,
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}, nil
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}
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func NewCursorKey(id gid.GID, t time.Time) CursorKey {
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var cursorKey CursorKey
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copy(cursorKey[:16], id[:])
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_ = binary.PutVarint(cursorKey[16:], t.UnixMicro())
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return cursorKey
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func NewCursorKey(id gid.GID, value any) CursorKey {
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return CursorKey{
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ID: id,
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Value: value,
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}
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}
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func (ck CursorKey) Bytes() []byte {
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return ck[:]
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data, _ := ck.MarshalBinary()
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return data
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}
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func (ck CursorKey) String() string {
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return base64.RawURLEncoding.EncodeToString(ck.Bytes())
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data, err := ck.MarshalBinary()
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if err != nil {
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return ""
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}
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return base64.RawURLEncoding.EncodeToString(data)
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}
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func (ck CursorKey) Timestamp() time.Time {
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unixMicro, _ := binary.Varint(ck[16:])
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seconds := unixMicro / 1e6
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nanoseconds := (unixMicro % 1e6) * 1e3
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return time.Unix(seconds, nanoseconds)
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}
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func (ck CursorKey) ID() gid.GID {
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return gid.GID(ck[:16])
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func (ck CursorKey) FieldValue() any {
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return ck.Value
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}
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func (ck CursorKey) MarshalText() ([]byte, error) {
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@@ -97,27 +98,92 @@ func (ck CursorKey) MarshalText() ([]byte, error) {
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}
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func (ck *CursorKey) UnmarshalText(data []byte) error {
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ck2, err := ParseCursorKey(string(data))
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newCk, err := ParseCursorKey(string(data))
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if err != nil {
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return err
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}
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*ck = ck2
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*ck = newCk
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return nil
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}
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func (ck CursorKey) MarshalBinary() ([]byte, error) {
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return ck.Bytes(), nil
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arr := []any{ck.ID.String(), ck.Value}
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return json.Marshal(arr)
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}
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func (ck *CursorKey) UnmarshalBinary(b []byte) error {
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ck2, err := CursorKeyFromBytes(b)
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if err != nil {
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func (ck *CursorKey) UnmarshalBinary(data []byte) error {
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var arr []json.RawMessage
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if err := json.Unmarshal(data, &arr); err != nil {
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return err
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}
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*ck = ck2
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if len(arr) != 2 {
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return ErrInvalidFormat
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}
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// Parse the ID
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var idStr string
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if err := json.Unmarshal(arr[0], &idStr); err != nil {
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return ErrInvalidFormat
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}
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id, err := gid.ParseGID(idStr)
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if err != nil {
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return ErrInvalidFormat
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}
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var value any
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if err := json.Unmarshal(arr[1], &value); err != nil {
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return ErrInvalidFormat
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}
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ck.ID = id
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ck.Value = value
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return nil
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}
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func (ck CursorKey) MarshalJSON() ([]byte, error) {
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arr := []any{ck.ID.String(), ck.Value}
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return json.Marshal(arr)
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}
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func (ck *CursorKey) UnmarshalJSON(data []byte) error {
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var arr []json.RawMessage
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if err := json.Unmarshal(data, &arr); err != nil {
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var s string
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if err := json.Unmarshal(data, &s); err != nil {
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return err
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}
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parsed, err := ParseCursorKey(s)
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if err != nil {
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return err
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}
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*ck = parsed
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return nil
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}
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if len(arr) != 2 {
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return ErrInvalidFormat
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}
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var idStr string
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if err := json.Unmarshal(arr[0], &idStr); err != nil {
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return ErrInvalidFormat
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}
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id, err := gid.ParseGID(idStr)
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if err != nil {
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return ErrInvalidFormat
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}
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var value any
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if err := json.Unmarshal(arr[1], &value); err != nil {
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return ErrInvalidFormat
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}
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ck.ID = id
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ck.Value = value
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return nil
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}
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49
pkg/page/order_direction.go
Normal file
49
pkg/page/order_direction.go
Normal file
@@ -0,0 +1,49 @@
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// Copyright (c) 2025 Probo Inc <hello@getprobo.com>.
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//
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// Permission to use, copy, modify, and/or distribute this software for any
|
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// purpose with or without fee is hereby granted, provided that the above
|
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// copyright notice and this permission notice appear in all copies.
|
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//
|
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// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
|
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// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
|
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// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
|
||||
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
|
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// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
|
||||
// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
|
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// PERFORMANCE OF THIS SOFTWARE.
|
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|
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package page
|
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|
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import (
|
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"fmt"
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)
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|
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type OrderDirection string
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const (
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OrderDirectionAsc OrderDirection = "ASC"
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OrderDirectionDesc OrderDirection = "DESC"
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)
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func (od OrderDirection) MarshalText() ([]byte, error) {
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return []byte(od.String()), nil
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}
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func (od *OrderDirection) UnmarshalText(data []byte) error {
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val := string(data)
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switch val {
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case OrderDirectionAsc.String():
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*od = OrderDirectionAsc
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case OrderDirectionDesc.String():
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*od = OrderDirectionDesc
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default:
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return fmt.Errorf("invalid OrderDirection value: %q", val)
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}
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|
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return nil
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}
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|
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func (od OrderDirection) String() string {
|
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return string(od)
|
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}
|
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71
pkg/page/order_field.go
Normal file
71
pkg/page/order_field.go
Normal file
@@ -0,0 +1,71 @@
|
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// Copyright (c) 2025 Probo Inc <hello@getprobo.com>.
|
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//
|
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// Permission to use, copy, modify, and/or distribute this software for any
|
||||
// purpose with or without fee is hereby granted, provided that the above
|
||||
// copyright notice and this permission notice appear in all copies.
|
||||
//
|
||||
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
|
||||
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
|
||||
// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
|
||||
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
|
||||
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
|
||||
// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
|
||||
// PERFORMANCE OF THIS SOFTWARE.
|
||||
|
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package page
|
||||
|
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import (
|
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"fmt"
|
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)
|
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|
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type (
|
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OrderField interface {
|
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Column() string
|
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}
|
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|
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BaseOrderField string
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)
|
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|
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const (
|
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OrderFieldCreatedAt BaseOrderField = "CREATED_AT"
|
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OrderFieldUpdatedAt BaseOrderField = "UPDATED_AT"
|
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OrderFieldName BaseOrderField = "NAME"
|
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)
|
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|
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func (of BaseOrderField) String() string {
|
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return string(of)
|
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}
|
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|
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func (of BaseOrderField) Column() string {
|
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switch of {
|
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case OrderFieldCreatedAt:
|
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return "created_at"
|
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case OrderFieldUpdatedAt:
|
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return "updated_at"
|
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case OrderFieldName:
|
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return "name"
|
||||
default:
|
||||
return ""
|
||||
}
|
||||
}
|
||||
|
||||
func (of BaseOrderField) MarshalText() ([]byte, error) {
|
||||
return []byte(of.String()), nil
|
||||
}
|
||||
|
||||
func (of *BaseOrderField) UnmarshalText(data []byte) error {
|
||||
val := string(data)
|
||||
|
||||
switch val {
|
||||
case OrderFieldCreatedAt.String():
|
||||
*of = OrderFieldCreatedAt
|
||||
case OrderFieldUpdatedAt.String():
|
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*of = OrderFieldUpdatedAt
|
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case OrderFieldName.String():
|
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*of = OrderFieldName
|
||||
default:
|
||||
return fmt.Errorf("invalid BaseOrderField value: %q", val)
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
@@ -16,7 +16,7 @@ package page
|
||||
|
||||
type (
|
||||
Paginable interface {
|
||||
CursorKey() CursorKey
|
||||
CursorKey(orderBy OrderField) CursorKey
|
||||
}
|
||||
|
||||
PageInfo struct {
|
||||
@@ -25,8 +25,9 @@ type (
|
||||
}
|
||||
|
||||
Page[T Paginable] struct {
|
||||
Info *PageInfo
|
||||
Data []T
|
||||
Info *PageInfo
|
||||
Cursor *Cursor
|
||||
Data []T
|
||||
}
|
||||
)
|
||||
|
||||
@@ -73,7 +74,7 @@ func NewPage[T Paginable](data []T, c *Cursor) *Page[T] {
|
||||
edges = edges[0 : len(edges)-1]
|
||||
}
|
||||
|
||||
if c.Key != nil && *c.Key == firstFromData.CursorKey() {
|
||||
if c.Key != nil && c.Key.String() == firstFromData.CursorKey(c.OrderBy.Field).String() {
|
||||
pi.HasPrev = true
|
||||
}
|
||||
|
||||
@@ -97,7 +98,7 @@ func NewPage[T Paginable](data []T, c *Cursor) *Page[T] {
|
||||
edges = edges[1:]
|
||||
}
|
||||
|
||||
if c.Key != nil && *c.Key == firstFromData.CursorKey() {
|
||||
if c.Key != nil && c.Key.String() == firstFromData.CursorKey(c.OrderBy.Field).String() {
|
||||
pi.HasNext = true
|
||||
}
|
||||
|
||||
@@ -109,7 +110,8 @@ func NewPage[T Paginable](data []T, c *Cursor) *Page[T] {
|
||||
}
|
||||
|
||||
return &Page[T]{
|
||||
Info: pi,
|
||||
Data: edges,
|
||||
Info: pi,
|
||||
Cursor: c,
|
||||
Data: edges,
|
||||
}
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user