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author | Daniel Baumann <daniel@debian.org> | 2024-10-18 20:33:49 +0200 |
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committer | Daniel Baumann <daniel@debian.org> | 2024-12-12 23:57:56 +0100 |
commit | e68b9d00a6e05b3a941f63ffb696f91e554ac5ec (patch) | |
tree | 97775d6c13b0f416af55314eb6a89ef792474615 /modules/paginator | |
parent | Initial commit. (diff) | |
download | forgejo-e68b9d00a6e05b3a941f63ffb696f91e554ac5ec.tar.xz forgejo-e68b9d00a6e05b3a941f63ffb696f91e554ac5ec.zip |
Adding upstream version 9.0.3.
Signed-off-by: Daniel Baumann <daniel@debian.org>
Diffstat (limited to '')
-rw-r--r-- | modules/paginator/paginator.go | 204 | ||||
-rw-r--r-- | modules/paginator/paginator_test.go | 312 |
2 files changed, 516 insertions, 0 deletions
diff --git a/modules/paginator/paginator.go b/modules/paginator/paginator.go new file mode 100644 index 0000000..8258d19 --- /dev/null +++ b/modules/paginator/paginator.go @@ -0,0 +1,204 @@ +// Copyright 2022 The Gitea Authors. +// Copyright 2015 https://github.com/unknwon. Licensed under the Apache License, Version 2.0 +// SPDX-License-Identifier: Apache-2.0 + +package paginator + +/* +In template: + +```html +{{if not .Page.IsFirst}}[First](1){{end}} +{{if .Page.HasPrevious}}[Previous]({{.Page.Previous}}){{end}} + +{{range .Page.Pages}} + {{if eq .Num -1}} + ... + {{else}} + {{.Num}}{{if .IsCurrent}}(current){{end}} + {{end}} +{{end}} + +{{if .Page.HasNext}}[Next]({{.Page.Next}}){{end}} +{{if not .Page.IsLast}}[Last]({{.Page.TotalPages}}){{end}} +``` + +Output: + +``` +[First](1) [Previous](2) ... 2 3(current) 4 ... [Next](4) [Last](5) +``` +*/ + +// Paginator represents a set of results of pagination calculations. +type Paginator struct { + total int // total rows count + pagingNum int // how many rows in one page + current int // current page number + numPages int // how many pages to show on the UI +} + +// New initialize a new pagination calculation and returns a Paginator as result. +func New(total, pagingNum, current, numPages int) *Paginator { + if pagingNum <= 0 { + pagingNum = 1 + } + if current <= 0 { + current = 1 + } + p := &Paginator{total, pagingNum, current, numPages} + if p.current > p.TotalPages() { + p.current = p.TotalPages() + } + return p +} + +// IsFirst returns true if current page is the first page. +func (p *Paginator) IsFirst() bool { + return p.current == 1 +} + +// HasPrevious returns true if there is a previous page relative to current page. +func (p *Paginator) HasPrevious() bool { + return p.current > 1 +} + +func (p *Paginator) Previous() int { + if !p.HasPrevious() { + return p.current + } + return p.current - 1 +} + +// HasNext returns true if there is a next page relative to current page. +func (p *Paginator) HasNext() bool { + return p.total > p.current*p.pagingNum +} + +func (p *Paginator) Next() int { + if !p.HasNext() { + return p.current + } + return p.current + 1 +} + +// IsLast returns true if current page is the last page. +func (p *Paginator) IsLast() bool { + if p.total == 0 { + return true + } + return p.total > (p.current-1)*p.pagingNum && !p.HasNext() +} + +// Total returns number of total rows. +func (p *Paginator) Total() int { + return p.total +} + +// TotalPages returns number of total pages. +func (p *Paginator) TotalPages() int { + if p.total == 0 { + return 1 + } + return (p.total + p.pagingNum - 1) / p.pagingNum +} + +// Current returns current page number. +func (p *Paginator) Current() int { + return p.current +} + +// PagingNum returns number of page size. +func (p *Paginator) PagingNum() int { + return p.pagingNum +} + +// Page presents a page in the paginator. +type Page struct { + num int + isCurrent bool +} + +func (p *Page) Num() int { + return p.num +} + +func (p *Page) IsCurrent() bool { + return p.isCurrent +} + +func getMiddleIdx(numPages int) int { + return (numPages + 1) / 2 +} + +// Pages returns a list of nearby page numbers relative to current page. +// If value is -1 means "..." that more pages are not showing. +func (p *Paginator) Pages() []*Page { + if p.numPages == 0 { + return []*Page{} + } else if p.numPages == 1 && p.TotalPages() == 1 { + // Only show current page. + return []*Page{{1, true}} + } + + // Total page number is less or equal. + if p.TotalPages() <= p.numPages { + pages := make([]*Page, p.TotalPages()) + for i := range pages { + pages[i] = &Page{i + 1, i+1 == p.current} + } + return pages + } + + numPages := p.numPages + offsetIdx := 0 + hasMoreNext := false + + // Check more previous and next pages. + previousNum := getMiddleIdx(p.numPages) - 1 + if previousNum > p.current-1 { + previousNum -= previousNum - (p.current - 1) + } + nextNum := p.numPages - previousNum - 1 + if p.current+nextNum > p.TotalPages() { + delta := nextNum - (p.TotalPages() - p.current) + nextNum -= delta + previousNum += delta + } + + offsetVal := p.current - previousNum + if offsetVal > 1 { + numPages++ + offsetIdx = 1 + } + + if p.current+nextNum < p.TotalPages() { + numPages++ + hasMoreNext = true + } + + pages := make([]*Page, numPages) + + // There are more previous pages. + if offsetIdx == 1 { + pages[0] = &Page{-1, false} + } + // There are more next pages. + if hasMoreNext { + pages[len(pages)-1] = &Page{-1, false} + } + + // Check previous pages. + for i := 0; i < previousNum; i++ { + pages[offsetIdx+i] = &Page{i + offsetVal, false} + } + + pages[offsetIdx+previousNum] = &Page{p.current, true} + + // Check next pages. + for i := 1; i <= nextNum; i++ { + pages[offsetIdx+previousNum+i] = &Page{p.current + i, false} + } + + return pages +} diff --git a/modules/paginator/paginator_test.go b/modules/paginator/paginator_test.go new file mode 100644 index 0000000..8a56ee5 --- /dev/null +++ b/modules/paginator/paginator_test.go @@ -0,0 +1,312 @@ +// Copyright 2022 The Gitea Authors. +// Copyright 2015 https://github.com/unknwon. Licensed under the Apache License, Version 2.0 +// SPDX-License-Identifier: Apache-2.0 + +package paginator + +import ( + "testing" + + "github.com/stretchr/testify/assert" +) + +func TestPaginator(t *testing.T) { + t.Run("Basic logics", func(t *testing.T) { + p := New(0, -1, -1, 0) + assert.Equal(t, 1, p.PagingNum()) + assert.True(t, p.IsFirst()) + assert.False(t, p.HasPrevious()) + assert.Equal(t, 1, p.Previous()) + assert.False(t, p.HasNext()) + assert.Equal(t, 1, p.Next()) + assert.True(t, p.IsLast()) + assert.Equal(t, 0, p.Total()) + + p = New(1, 10, 2, 0) + assert.Equal(t, 10, p.PagingNum()) + assert.True(t, p.IsFirst()) + assert.False(t, p.HasPrevious()) + assert.False(t, p.HasNext()) + assert.True(t, p.IsLast()) + + p = New(10, 10, 1, 0) + assert.Equal(t, 10, p.PagingNum()) + assert.True(t, p.IsFirst()) + assert.False(t, p.HasPrevious()) + assert.False(t, p.HasNext()) + assert.True(t, p.IsLast()) + + p = New(11, 10, 1, 0) + assert.Equal(t, 10, p.PagingNum()) + assert.True(t, p.IsFirst()) + assert.False(t, p.HasPrevious()) + assert.True(t, p.HasNext()) + assert.Equal(t, 2, p.Next()) + assert.False(t, p.IsLast()) + + p = New(11, 10, 2, 0) + assert.Equal(t, 10, p.PagingNum()) + assert.False(t, p.IsFirst()) + assert.True(t, p.HasPrevious()) + assert.Equal(t, 1, p.Previous()) + assert.False(t, p.HasNext()) + assert.True(t, p.IsLast()) + + p = New(20, 10, 2, 0) + assert.Equal(t, 10, p.PagingNum()) + assert.False(t, p.IsFirst()) + assert.True(t, p.HasPrevious()) + assert.False(t, p.HasNext()) + assert.True(t, p.IsLast()) + + p = New(25, 10, 2, 0) + assert.Equal(t, 10, p.PagingNum()) + assert.False(t, p.IsFirst()) + assert.True(t, p.HasPrevious()) + assert.True(t, p.HasNext()) + assert.False(t, p.IsLast()) + }) + + t.Run("Generate pages", func(t *testing.T) { + p := New(0, 10, 1, 0) + pages := p.Pages() + assert.Empty(t, pages) + }) + + t.Run("Only current page", func(t *testing.T) { + p := New(0, 10, 1, 1) + pages := p.Pages() + assert.Len(t, pages, 1) + assert.Equal(t, 1, pages[0].Num()) + assert.True(t, pages[0].IsCurrent()) + + p = New(1, 10, 1, 1) + pages = p.Pages() + assert.Len(t, pages, 1) + assert.Equal(t, 1, pages[0].Num()) + assert.True(t, pages[0].IsCurrent()) + }) + + t.Run("Total page number is less or equal", func(t *testing.T) { + p := New(1, 10, 1, 2) + pages := p.Pages() + assert.Len(t, pages, 1) + assert.Equal(t, 1, pages[0].Num()) + assert.True(t, pages[0].IsCurrent()) + + p = New(11, 10, 1, 2) + pages = p.Pages() + assert.Len(t, pages, 2) + assert.Equal(t, 1, pages[0].Num()) + assert.True(t, pages[0].IsCurrent()) + assert.Equal(t, 2, pages[1].Num()) + assert.False(t, pages[1].IsCurrent()) + + p = New(11, 10, 2, 2) + pages = p.Pages() + assert.Len(t, pages, 2) + assert.Equal(t, 1, pages[0].Num()) + assert.False(t, pages[0].IsCurrent()) + assert.Equal(t, 2, pages[1].Num()) + assert.True(t, pages[1].IsCurrent()) + + p = New(25, 10, 2, 3) + pages = p.Pages() + assert.Len(t, pages, 3) + assert.Equal(t, 1, pages[0].Num()) + assert.False(t, pages[0].IsCurrent()) + assert.Equal(t, 2, pages[1].Num()) + assert.True(t, pages[1].IsCurrent()) + assert.Equal(t, 3, pages[2].Num()) + assert.False(t, pages[2].IsCurrent()) + }) + + t.Run("Has more previous pages ", func(t *testing.T) { + // ... 2 + p := New(11, 10, 2, 1) + pages := p.Pages() + assert.Len(t, pages, 2) + assert.Equal(t, -1, pages[0].Num()) + assert.False(t, pages[0].IsCurrent()) + assert.Equal(t, 2, pages[1].Num()) + assert.True(t, pages[1].IsCurrent()) + + // ... 2 3 + p = New(21, 10, 2, 2) + pages = p.Pages() + assert.Len(t, pages, 3) + assert.Equal(t, -1, pages[0].Num()) + assert.False(t, pages[0].IsCurrent()) + assert.Equal(t, 2, pages[1].Num()) + assert.True(t, pages[1].IsCurrent()) + assert.Equal(t, 3, pages[2].Num()) + assert.False(t, pages[2].IsCurrent()) + + // ... 2 3 4 + p = New(31, 10, 3, 3) + pages = p.Pages() + assert.Len(t, pages, 4) + assert.Equal(t, -1, pages[0].Num()) + assert.False(t, pages[0].IsCurrent()) + assert.Equal(t, 2, pages[1].Num()) + assert.False(t, pages[1].IsCurrent()) + assert.Equal(t, 3, pages[2].Num()) + assert.True(t, pages[2].IsCurrent()) + assert.Equal(t, 4, pages[3].Num()) + assert.False(t, pages[3].IsCurrent()) + + // ... 3 4 5 + p = New(41, 10, 4, 3) + pages = p.Pages() + assert.Len(t, pages, 4) + assert.Equal(t, -1, pages[0].Num()) + assert.False(t, pages[0].IsCurrent()) + assert.Equal(t, 3, pages[1].Num()) + assert.False(t, pages[1].IsCurrent()) + assert.Equal(t, 4, pages[2].Num()) + assert.True(t, pages[2].IsCurrent()) + assert.Equal(t, 5, pages[3].Num()) + assert.False(t, pages[3].IsCurrent()) + + // ... 4 5 6 7 8 9 10 + p = New(100, 10, 9, 7) + pages = p.Pages() + assert.Len(t, pages, 8) + assert.Equal(t, -1, pages[0].Num()) + assert.False(t, pages[0].IsCurrent()) + assert.Equal(t, 4, pages[1].Num()) + assert.False(t, pages[1].IsCurrent()) + assert.Equal(t, 5, pages[2].Num()) + assert.False(t, pages[2].IsCurrent()) + assert.Equal(t, 6, pages[3].Num()) + assert.False(t, pages[3].IsCurrent()) + assert.Equal(t, 7, pages[4].Num()) + assert.False(t, pages[4].IsCurrent()) + assert.Equal(t, 8, pages[5].Num()) + assert.False(t, pages[5].IsCurrent()) + assert.Equal(t, 9, pages[6].Num()) + assert.True(t, pages[6].IsCurrent()) + assert.Equal(t, 10, pages[7].Num()) + assert.False(t, pages[7].IsCurrent()) + }) + + t.Run("Has more next pages", func(t *testing.T) { + // 1 ... + p := New(21, 10, 1, 1) + pages := p.Pages() + assert.Len(t, pages, 2) + assert.Equal(t, 1, pages[0].Num()) + assert.True(t, pages[0].IsCurrent()) + assert.Equal(t, -1, pages[1].Num()) + assert.False(t, pages[1].IsCurrent()) + + // 1 2 ... + p = New(21, 10, 1, 2) + pages = p.Pages() + assert.Len(t, pages, 3) + assert.Equal(t, 1, pages[0].Num()) + assert.True(t, pages[0].IsCurrent()) + assert.Equal(t, 2, pages[1].Num()) + assert.False(t, pages[1].IsCurrent()) + assert.Equal(t, -1, pages[2].Num()) + assert.False(t, pages[2].IsCurrent()) + + // 1 2 3 ... + p = New(31, 10, 2, 3) + pages = p.Pages() + assert.Len(t, pages, 4) + assert.Equal(t, 1, pages[0].Num()) + assert.False(t, pages[0].IsCurrent()) + assert.Equal(t, 2, pages[1].Num()) + assert.True(t, pages[1].IsCurrent()) + assert.Equal(t, 3, pages[2].Num()) + assert.False(t, pages[2].IsCurrent()) + assert.Equal(t, -1, pages[3].Num()) + assert.False(t, pages[3].IsCurrent()) + + // 1 2 3 ... + p = New(41, 10, 2, 3) + pages = p.Pages() + assert.Len(t, pages, 4) + assert.Equal(t, 1, pages[0].Num()) + assert.False(t, pages[0].IsCurrent()) + assert.Equal(t, 2, pages[1].Num()) + assert.True(t, pages[1].IsCurrent()) + assert.Equal(t, 3, pages[2].Num()) + assert.False(t, pages[2].IsCurrent()) + assert.Equal(t, -1, pages[3].Num()) + assert.False(t, pages[3].IsCurrent()) + + // 1 2 3 4 5 6 7 ... + p = New(100, 10, 1, 7) + pages = p.Pages() + assert.Len(t, pages, 8) + assert.Equal(t, 1, pages[0].Num()) + assert.True(t, pages[0].IsCurrent()) + assert.Equal(t, 2, pages[1].Num()) + assert.False(t, pages[1].IsCurrent()) + assert.Equal(t, 3, pages[2].Num()) + assert.False(t, pages[2].IsCurrent()) + assert.Equal(t, 4, pages[3].Num()) + assert.False(t, pages[3].IsCurrent()) + assert.Equal(t, 5, pages[4].Num()) + assert.False(t, pages[4].IsCurrent()) + assert.Equal(t, 6, pages[5].Num()) + assert.False(t, pages[5].IsCurrent()) + assert.Equal(t, 7, pages[6].Num()) + assert.False(t, pages[6].IsCurrent()) + assert.Equal(t, -1, pages[7].Num()) + assert.False(t, pages[7].IsCurrent()) + + // 1 2 3 4 5 6 7 ... + p = New(100, 10, 2, 7) + pages = p.Pages() + assert.Len(t, pages, 8) + assert.Equal(t, 1, pages[0].Num()) + assert.False(t, pages[0].IsCurrent()) + assert.Equal(t, 2, pages[1].Num()) + assert.True(t, pages[1].IsCurrent()) + assert.Equal(t, 3, pages[2].Num()) + assert.False(t, pages[2].IsCurrent()) + assert.Equal(t, 4, pages[3].Num()) + assert.False(t, pages[3].IsCurrent()) + assert.Equal(t, 5, pages[4].Num()) + assert.False(t, pages[4].IsCurrent()) + assert.Equal(t, 6, pages[5].Num()) + assert.False(t, pages[5].IsCurrent()) + assert.Equal(t, 7, pages[6].Num()) + assert.False(t, pages[6].IsCurrent()) + assert.Equal(t, -1, pages[7].Num()) + assert.False(t, pages[7].IsCurrent()) + }) + + t.Run("Has both more previous and next pages", func(t *testing.T) { + // ... 2 3 ... + p := New(35, 10, 2, 2) + pages := p.Pages() + assert.Len(t, pages, 4) + assert.Equal(t, -1, pages[0].Num()) + assert.False(t, pages[0].IsCurrent()) + assert.Equal(t, 2, pages[1].Num()) + assert.True(t, pages[1].IsCurrent()) + assert.Equal(t, 3, pages[2].Num()) + assert.False(t, pages[2].IsCurrent()) + assert.Equal(t, -1, pages[3].Num()) + assert.False(t, pages[3].IsCurrent()) + + // ... 2 3 4 ... + p = New(49, 10, 3, 3) + pages = p.Pages() + assert.Len(t, pages, 5) + assert.Equal(t, -1, pages[0].Num()) + assert.False(t, pages[0].IsCurrent()) + assert.Equal(t, 2, pages[1].Num()) + assert.False(t, pages[1].IsCurrent()) + assert.Equal(t, 3, pages[2].Num()) + assert.True(t, pages[2].IsCurrent()) + assert.Equal(t, 4, pages[3].Num()) + assert.False(t, pages[3].IsCurrent()) + assert.Equal(t, -1, pages[4].Num()) + assert.False(t, pages[4].IsCurrent()) + }) +} |