-
Notifications
You must be signed in to change notification settings - Fork 0
/
pagination.go
210 lines (167 loc) · 4.98 KB
/
pagination.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
// Copyright 2019 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package page
import (
"errors"
"fmt"
"github.com/spf13/cast"
"github.com/sunwei/hugo-playground/config"
"math"
)
// PaginatorProvider provides two ways to create a page paginator.
type PaginatorProvider interface {
Paginator(options ...any) (*Pager, error)
Paginate(seq any, options ...any) (*Pager, error)
}
// Pager represents one of the elements in a paginator.
// The number, starting on 1, represents its place.
type Pager struct {
number int
*Paginator
}
func (p Pager) String() string {
return fmt.Sprintf("Pager %d", p.number)
}
type paginatedElement interface {
Len() int
}
type pagers []*Pager
type Paginator struct {
paginatedElements []paginatedElement
pagers
paginationURLFactory
total int
size int
}
type paginationURLFactory func(int) string
func ResolvePagerSize(cfg config.Provider, options ...any) (int, error) {
if len(options) == 0 {
return cfg.GetInt("paginate"), nil
}
if len(options) > 1 {
return -1, errors.New("too many arguments, 'pager size' is currently the only option")
}
pas, err := cast.ToIntE(options[0])
if err != nil || pas <= 0 {
return -1, errors.New("'pager size' must be a positive integer")
}
return pas, nil
}
func Paginate(td TargetPathDescriptor, seq any, pagerSize int) (*Paginator, error) {
if pagerSize <= 0 {
return nil, errors.New("'paginate' configuration setting must be positive to paginate")
}
urlFactory := newPaginationURLFactory(td)
var paginator *Paginator
groups, err := ToPagesGroup(seq)
if err != nil {
return nil, err
}
if groups != nil {
paginator, _ = newPaginatorFromPageGroups(groups, pagerSize, urlFactory)
} else {
pages, err := ToPages(seq)
if err != nil {
return nil, err
}
paginator, _ = newPaginatorFromPages(pages, pagerSize, urlFactory)
}
return paginator, nil
}
func newPaginationURLFactory(d TargetPathDescriptor) paginationURLFactory {
return func(pageNumber int) string {
pathDescriptor := d
var rel string
if pageNumber > 1 {
rel = fmt.Sprintf("/%s/%d/", d.PathSpec.PaginatePath, pageNumber)
pathDescriptor.Addends = rel
}
return CreateTargetPaths(pathDescriptor).RelPermalink(d.PathSpec)
}
}
func newPaginatorFromPageGroups(pageGroups PagesGroup, size int, urlFactory paginationURLFactory) (*Paginator, error) {
if size <= 0 {
return nil, errors.New("Paginator size must be positive")
}
split := splitPageGroups(pageGroups, size)
return newPaginator(split, pageGroups.Len(), size, urlFactory)
}
func splitPageGroups(pageGroups PagesGroup, size int) []paginatedElement {
type keyPage struct {
key any
page Page
}
var (
split []paginatedElement
flattened []keyPage
)
for _, g := range pageGroups {
for _, p := range g.Pages {
flattened = append(flattened, keyPage{g.Key, p})
}
}
numPages := len(flattened)
for low, j := 0, numPages; low < j; low += size {
high := int(math.Min(float64(low+size), float64(numPages)))
var (
pg PagesGroup
key any
groupIndex = -1
)
for k := low; k < high; k++ {
kp := flattened[k]
if key == nil || key != kp.key {
key = kp.key
pg = append(pg, PageGroup{Key: key})
groupIndex++
}
pg[groupIndex].Pages = append(pg[groupIndex].Pages, kp.page)
}
split = append(split, pg)
}
return split
}
func newPaginator(elements []paginatedElement, total, size int, urlFactory paginationURLFactory) (*Paginator, error) {
p := &Paginator{total: total, paginatedElements: elements, size: size, paginationURLFactory: urlFactory}
var ps pagers
if len(elements) > 0 {
ps = make(pagers, len(elements))
for i := range p.paginatedElements {
ps[i] = &Pager{number: (i + 1), Paginator: p}
}
} else {
ps = make(pagers, 1)
ps[0] = &Pager{number: 1, Paginator: p}
}
p.pagers = ps
return p, nil
}
func newPaginatorFromPages(pages Pages, size int, urlFactory paginationURLFactory) (*Paginator, error) {
if size <= 0 {
return nil, errors.New("Paginator size must be positive")
}
split := splitPages(pages, size)
return newPaginator(split, len(pages), size, urlFactory)
}
func splitPages(pages Pages, size int) []paginatedElement {
var split []paginatedElement
for low, j := 0, len(pages); low < j; low += size {
high := int(math.Min(float64(low+size), float64(len(pages))))
split = append(split, pages[low:high])
}
return split
}
// Pagers returns a list of pagers that can be used to build a pagination menu.
func (p *Paginator) Pagers() pagers {
return p.pagers
}