Merge pull request #36 from rizalgowandy/arwego/feat/pagination

Add Pagination Package
rizalgowandy · May 8, 2022 · 71de41b · 71de41b
2 parents 7ebf47a + 3f71532
commit 71de41b
Showing 1 changed file with 103 additions and 0 deletions.
diff --git a/pkg/pagination/pagination.go b/pkg/pagination/pagination.go
@@ -0,0 +1,103 @@
+package pagination
+
+import (
+	"strconv"
+)
+
+// Request is a parameter to return list of data with pagination.
+// Request is optional, most fields automatically filled by system.
+// If you already have a response with pagination,
+// you can generate pagination request directly to traverse next or prev page.
+type Request struct {
+	// Order of the resources in the response. desc (default), asc.
+	// Order is optional.
+	Order string `json:"order"`
+	// Limit number of results per call. Accepted values: 0 - 100. Default 25
+	// Limit is optional.
+	Limit int `json:"limit"`
+	// StartingAfter is a cursor for use in pagination.
+	// StartingAfter is a resource ID that defines your place in the list.
+	// StartingAfter is optional.
+	StartingAfter *string `json:"starting_after"`
+	// EndingBefore is cursor for use in pagination.
+	// EndingBefore is a resource ID that defines your place in the list.
+	// EndingBefore is optional.
+	EndingBefore *string `json:"ending_before"`
+}
+
+func (p Request) QueryParams() map[string]string {
+	res := map[string]string{}
+	if p.Order != "" {
+		res["order"] = p.Order
+	}
+	if p.Limit > 0 {
+		res["limit"] = strconv.Itoa(p.Limit)
+	}
+	if p.StartingAfter != nil {
+		res["starting_after"] = *p.StartingAfter
+	}
+	if p.EndingBefore != nil {
+		res["ending_before"] = *p.EndingBefore
+	}
+	return res
+}
+
+type Response struct {
+	Order         string  `json:"order"`
+	StartingAfter *string `json:"starting_after"`
+	EndingBefore  *string `json:"ending_before"`
+	Total         int     `json:"total"`
+	Yielded       int     `json:"yielded"`
+	Limit         int     `json:"limit"`
+	PreviousURI   *string `json:"previous_uri"`
+	NextURI       *string `json:"next_uri"`
+	// CursorRange returns cursors for starting after and ending before.
+	// Format: [starting_after, ending_before].
+	CursorRange []string `json:"cursor_range"`
+}
+
+// HasPrevPage returns true if prev page exists and can be traversed.
+func (p *Response) HasPrevPage() bool {
+	return p.PreviousURI != nil
+}
+
+// HasNextPage returns true if next page exists and can be traversed.
+func (p *Response) HasNextPage() bool {
+	return p.NextURI != nil
+}
+
+// PrevPageCursor returns cursor to be used as ending before value.
+func (p *Response) PrevPageCursor() *string {
+	if len(p.CursorRange) < 1 {
+		return nil
+	}
+	return &p.CursorRange[0]
+}
+
+// NextPageCursor returns cursor to be used as starting after value.
+func (p *Response) NextPageCursor() *string {
+	if len(p.CursorRange) < 2 {
+		return nil
+	}
+	return &p.CursorRange[1]
+}
+
+// PrevPageRequest returns pagination request for the prev page result.
+func (p *Response) PrevPageRequest() Request {
+	return Request{
+		Order:         p.Order,
+		Limit:         p.Limit,
+		StartingAfter: nil,
+		EndingBefore:  p.PrevPageCursor(),
+	}
+}
+
+// NextPageRequest returns pagination request for the next page result.
+func (p *Response) NextPageRequest() Request {
+	return Request{
+		Order:         p.Order,
+		Limit:         p.Limit,
+		StartingAfter: p.NextPageCursor(),
+		EndingBefore:  nil,
+	}
+}