Add a new Cursor form type

To hold the common logic of detecting pagination, forming the key, and
splitting its values later on.

I can take advantage that a form with action="get" already adds its
fields to the query string to have a common template for pagination. The
only problem is that i have different column spans for different tables,
therefore had to add a colspan to the struct.

pkg/booking/admin.go

@@ -172,7 +172,7 @@ func collectBookingEntries(ctx context.Context, conn *database.Conn, lang langua
 		order by lower(stay) desc
 		       , booking_id desc
 		LIMIT %d
-	`, where, filters.perPage+1), args...)
+	`, where, filters.PerPage()+1), args...)
 	if err != nil {
 		return nil, err
 	}
@@ -235,7 +235,7 @@ func (page bookingIndex) MustRender(w http.ResponseWriter, r *http.Request, user
 		}
 		ods.MustWriteResponse(w, table, user.Locale.Pgettext("bookings.ods", "filename"))
 	default:
-		if httplib.IsHTMxRequest(r) && page.Filters.pagination {
+		if httplib.IsHTMxRequest(r) && page.Filters.Paginated() {
 			template.MustRenderAdminNoLayout(w, r, user, company, "booking/results.gohtml", page)
 		} else {
 			template.MustRenderAdminFiles(w, r, user, company, page, "booking/index.gohtml", "booking/results.gohtml")

pkg/booking/filter.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"net/http"
+	"strconv"
 	"strings"
 
 	"dev.tandem.ws/tandem/camper/pkg/auth"
@@ -13,22 +14,17 @@ import (
 )
 
 type filterForm struct {
-	locale        *locale.Locale
 	company       *auth.Company
-	perPage       int
-	pagination    bool
 	HolderName    *form.Input
 	BookingStatus *form.Select
 	FromDate      *form.Input
 	ToDate        *form.Input
-	Cursor        *form.Input
+	Cursor        *form.Cursor
 }
 
 func newFilterForm(ctx context.Context, conn *database.Conn, company *auth.Company, locale *locale.Locale) *filterForm {
 	return &filterForm{
-		locale:  locale,
 		company: company,
-		perPage: 25,
 		HolderName: &form.Input{
 			Name: "holder_name",
 		},
@@ -42,8 +38,9 @@ func newFilterForm(ctx context.Context, conn *database.Conn, company *auth.Compa
 		ToDate: &form.Input{
 			Name: "to_date",
 		},
-		Cursor: &form.Input{
+		Cursor: &form.Cursor{
-			Name: "cursor",
+			Name:    "cursor",
+			PerPage: 25,
 		},
 	}
 }
@@ -68,7 +65,6 @@ func (f *filterForm) Parse(r *http.Request) error {
 	f.FromDate.FillValue(r)
 	f.ToDate.FillValue(r)
 	f.Cursor.FillValue(r)
-	f.pagination = f.Cursor.Val != ""
 	return nil
 }
 
@@ -100,8 +96,8 @@ func (f *filterForm) BuildQuery(args []interface{}) (string, []interface{}) {
 	maybeAppendWhere("lower(stay) >= $%d", f.FromDate.Val, nil)
 	maybeAppendWhere("lower(stay) <= $%d", f.ToDate.Val, nil)
 
-	if f.Cursor.Val != "" {
+	if f.Paginated() {
-		params := strings.Split(f.Cursor.Val, ";")
+		params := f.Cursor.Params()
 		if len(params) == 2 {
 			where = append(where, fmt.Sprintf("(lower(stay), booking_id) < ($%d, $%d)", len(args)+1, len(args)+2))
 			args = append(args, params[0])
@@ -113,14 +109,9 @@ func (f *filterForm) BuildQuery(args []interface{}) (string, []interface{}) {
 }
 
 func (f *filterForm) buildCursor(bookings []*bookingEntry) []*bookingEntry {
-	if len(bookings) <= f.perPage {
+	return form.BuildCursor(f.Cursor, bookings, func(entry *bookingEntry) []string {
-		f.Cursor.Val = ""
+		return []string{entry.ArrivalDate.Format(database.ISODateFormat), strconv.Itoa(entry.ID)}
-		return bookings
+	})
-	}
-	bookings = bookings[:f.perPage]
-	last := bookings[f.perPage-1]
-	f.Cursor.Val = fmt.Sprintf("%s;%d", last.ArrivalDate.Format(database.ISODateFormat), last.ID)
-	return bookings
 }
 
 func (f *filterForm) HasValue() bool {
@@ -129,3 +120,11 @@ func (f *filterForm) HasValue() bool {
 		f.FromDate.Val != "" ||
 		f.ToDate.Val != ""
 }
+
+func (f *filterForm) PerPage() int {
+	return f.Cursor.PerPage
+}
+
+func (f *filterForm) Paginated() bool {
+	return f.Cursor.Pagination
+}

pkg/booking/prebooking.go

@@ -59,7 +59,7 @@ type prebookingIndex struct {
 }
 
 func (page prebookingIndex) MustRender(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company) {
-	if httplib.IsHTMxRequest(r) && page.Filters.pagination {
+	if httplib.IsHTMxRequest(r) && page.Filters.Paginated() {
 		template.MustRenderAdminNoLayout(w, r, user, company, "prebooking/results.gohtml", page)
 	} else {
 		template.MustRenderAdminFiles(w, r, user, company, page, "prebooking/index.gohtml", "prebooking/results.gohtml")

pkg/customer/admin.go

@@ -109,7 +109,7 @@ func collectCustomerEntries(ctx context.Context, conn *database.Conn, company *a
 		where (%s)
 		order by name, contact_id
 		LIMIT %d
-	`, where, filters.perPage+1), args...)
+	`, where, filters.PerPage()+1), args...)
 	if err != nil {
 		return nil, err
 	}
@@ -141,7 +141,7 @@ type customerIndex struct {
 }
 
 func (page *customerIndex) MustRender(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company) {
-	if httplib.IsHTMxRequest(r) && page.Filters.pagination {
+	if httplib.IsHTMxRequest(r) && page.Filters.Paginated() {
 		template.MustRenderAdminNoLayout(w, r, user, company, "customer/results.gohtml", page)
 	} else {
 		template.MustRenderAdminFiles(w, r, user, company, page, "customer/index.gohtml", "customer/results.gohtml")

pkg/customer/filter.go

@@ -3,6 +3,7 @@ package customer
 import (
 	"fmt"
 	"net/http"
+	"strconv"
 	"strings"
 
 	"dev.tandem.ws/tandem/camper/pkg/auth"
@@ -10,26 +11,24 @@ import (
 )
 
 type filterForm struct {
-	company    *auth.Company
+	company *auth.Company
-	perPage    int
+	Name    *form.Input
-	pagination bool
+	Email   *form.Input
-	Name       *form.Input
+	Cursor  *form.Cursor
-	Email      *form.Input
-	Cursor     *form.Input
 }
 
 func newFilterForm(company *auth.Company) *filterForm {
 	return &filterForm{
 		company: company,
-		perPage: 25,
 		Name: &form.Input{
 			Name: "name",
 		},
 		Email: &form.Input{
 			Name: "email",
 		},
-		Cursor: &form.Input{
+		Cursor: &form.Cursor{
-			Name: "cursor",
+			Name:    "cursor",
+			PerPage: 25,
 		},
 	}
 }
@@ -41,7 +40,6 @@ func (f *filterForm) Parse(r *http.Request) error {
 	f.Name.FillValue(r)
 	f.Email.FillValue(r)
 	f.Cursor.FillValue(r)
-	f.pagination = f.Cursor.Val != ""
 	return nil
 }
 
@@ -69,8 +67,8 @@ func (f *filterForm) BuildQuery(args []interface{}) (string, []interface{}) {
 		return "%" + v + "%"
 	})
 
-	if f.Cursor.Val != "" {
+	if f.Paginated() {
-		params := strings.Split(f.Cursor.Val, ";")
+		params := f.Cursor.Params()
 		if len(params) == 2 {
 			where = append(where, fmt.Sprintf("(name, contact_id) > ($%d, $%d)", len(args)+1, len(args)+2))
 			args = append(args, params[0])
@@ -82,17 +80,20 @@ func (f *filterForm) BuildQuery(args []interface{}) (string, []interface{}) {
 }
 
 func (f *filterForm) buildCursor(customers []*customerEntry) []*customerEntry {
-	if len(customers) <= f.perPage {
+	return form.BuildCursor(f.Cursor, customers, func(entry *customerEntry) []string {
-		f.Cursor.Val = ""
+		return []string{entry.Name, strconv.Itoa(entry.ID)}
-		return customers
+	})
-	}
-	customers = customers[:f.perPage]
-	last := customers[f.perPage-1]
-	f.Cursor.Val = fmt.Sprintf("%s;%d", last.Name, last.ID)
-	return customers
 }
 
 func (f *filterForm) HasValue() bool {
 	return f.Name.Val != "" ||
 		f.Email.Val != ""
 }
+
+func (f *filterForm) PerPage() int {
+	return f.Cursor.PerPage
+}
+
+func (f *filterForm) Paginated() bool {
+	return f.Cursor.Pagination
+}

pkg/form/cursor.go

@@ -0,0 +1,33 @@
+package form
+
+import (
+	"net/http"
+	"strings"
+)
+
+type Cursor struct {
+	PerPage    int
+	Pagination bool
+	Name       string
+	Val        string
+	Colspan    int
+}
+
+func (cursor *Cursor) FillValue(r *http.Request) {
+	cursor.Val = strings.TrimSpace(r.FormValue(cursor.Name))
+	cursor.Pagination = cursor.Val != ""
+}
+
+func (cursor *Cursor) Params() []string {
+	return strings.Split(cursor.Val, ";")
+}
+
+func BuildCursor[K interface{}](cursor *Cursor, elems []K, build func(K) []string) []K {
+	if len(elems) <= cursor.PerPage {
+		cursor.Val = ""
+		return elems
+	}
+	elems = elems[:cursor.PerPage]
+	cursor.Val = strings.Join(build(elems[cursor.PerPage-1]), ";")
+	return elems
+}

pkg/template/render.go

@@ -24,6 +24,7 @@ import (
 	"dev.tandem.ws/tandem/camper/pkg/auth"
 	"dev.tandem.ws/tandem/camper/pkg/build"
 	"dev.tandem.ws/tandem/camper/pkg/database"
+	"dev.tandem.ws/tandem/camper/pkg/form"
 	httplib "dev.tandem.ws/tandem/camper/pkg/http"
 )
 
@@ -161,6 +162,10 @@ func mustRenderLayout(w io.Writer, user *auth.User, company *auth.Company, templ
 			return int(num)
 		},
 		"slugify": Slugify,
+		"colspan": func(colspan int, cursor *form.Cursor) *form.Cursor {
+			cursor.Colspan = colspan
+			return cursor
+		},
 	})
 	templates = append(templates, "form.gohtml")
 	files := make([]string, len(templates))

web/templates/admin/booking/results.gohtml

@@ -7,22 +7,4 @@
         <td class="booking-status">{{ .StatusLabel }}</td>
     </tr>
 {{- end }}
-{{ if .Filters.Cursor.Val }}
+{{ template "pagination" .Filters.Cursor | colspan 5 }}
-    <tr>
-        <td colspan="5">
-            {{ with .Filters -}}
-                <form data-hx-get="/admin/bookings" data-hx-target="closest tr" data-hx-swap="outerHTML">
-                    {{ with .HolderName -}}<input type="hidden" name="{{ .Name }}"
-                                                  value="{{ .Val }}">{{- end }}
-                    {{ with .BookingStatus -}}<input type="hidden" name="{{ .Name }}"
-                                                     value="{{ .String }}">{{- end }}
-                    {{ with .FromDate -}}<input type="hidden" name="{{ .Name }}"
-                                                value="{{ .Val }}">{{- end }}
-                    {{ with .ToDate -}}<input type="hidden" name="{{ .Name }}" value="{{ .Val }}">{{- end }}
-                    {{ with .Cursor -}}<input type="hidden" name="{{ .Name }}" value="{{ .Val }}">{{- end }}
-                    <button type="submit">{{( pgettext "Load more" "action" )}}</button>
-                </form>
-            {{- end }}
-        <td>
-    </tr>
-{{- end }}

web/templates/admin/customer/results.gohtml

@@ -5,15 +5,4 @@
         <td>{{ .Phone }}</td>
     </tr>
 {{- end }}
-{{ if .Filters.Cursor.Val }}
+{{ template "pagination" .Filters.Cursor | colspan 3 }}
-    <tr>
-        <td colspan="3">
-            {{ with .Filters -}}
-                <form method="get" data-hx-push-url="false" data-hx-boost="true" data-hx-target="closest tr" data-hx-swap="outerHTML">
-                    {{ with .Cursor -}}<input type="hidden" name="{{ .Name }}" value="{{ .Val }}">{{- end }}
-                    <button type="submit">{{( pgettext "Load more" "action" )}}</button>
-                </form>
-            {{- end }}
-        <td>
-    </tr>
-{{- end }}

web/templates/admin/form.gohtml

@@ -82,3 +82,17 @@
             @click="document.body.classList.toggle('filters-visible')"
             type="button">{{(pgettext "Filters" "action")}}</button>
 {{- end }}
+
+{{ define "pagination" -}}
+    {{ if .Val }}
+        <tr>
+            <td colspan="{{ .Colspan }}">
+                <form method="get" data-hx-push-url="false" data-hx-boost="true" data-hx-target="closest tr"
+                      data-hx-swap="outerHTML">
+                    <input type="hidden" name="{{ .Name }}" value="{{ .Val }}">
+                    <button type="submit">{{( pgettext "Load more" "action" )}}</button>
+                </form>
+            <td>
+        </tr>
+    {{- end }}
+{{- end }}