hugo/hugolib/pagination.go
Bjørn Erik Pedersen dea71670c0
Add Hugo Piper with SCSS support and much more
Before this commit, you would have to use page bundles to do image processing etc. in Hugo.

This commit adds

* A new `/assets` top-level project or theme dir (configurable via `assetDir`)
* A new template func, `resources.Get` which can be used to "get a resource" that can be further processed.

This means that you can now do this in your templates (or shortcodes):

```bash
{{ $sunset := (resources.Get "images/sunset.jpg").Fill "300x200" }}
```

This also adds a new `extended` build tag that enables powerful SCSS/SASS support with source maps. To compile this from source, you will also need a C compiler installed:

```
HUGO_BUILD_TAGS=extended mage install
```

Note that you can use output of the SCSS processing later in a non-SCSSS-enabled Hugo.

The `SCSS` processor is a _Resource transformation step_ and it can be chained with the many others in a pipeline:

```bash
{{ $css := resources.Get "styles.scss" | resources.ToCSS | resources.PostCSS | resources.Minify | resources.Fingerprint }}
<link rel="stylesheet" href="{{ $styles.RelPermalink }}" integrity="{{ $styles.Data.Digest }}" media="screen">
```

The transformation funcs above have aliases, so it can be shortened to:

```bash
{{ $css := resources.Get "styles.scss" | toCSS | postCSS | minify | fingerprint }}
<link rel="stylesheet" href="{{ $styles.RelPermalink }}" integrity="{{ $styles.Data.Digest }}" media="screen">
```

A quick tip would be to avoid the fingerprinting part, and possibly also the not-superfast `postCSS` when you're doing development, as it allows Hugo to be smarter about the rebuilding.

Documentation will follow, but have a look at the demo repo in https://github.com/bep/hugo-sass-test

New functions to create `Resource` objects:

* `resources.Get` (see above)
* `resources.FromString`: Create a Resource from a string.

New `Resource` transformation funcs:

* `resources.ToCSS`: Compile `SCSS` or `SASS` into `CSS`.
* `resources.PostCSS`: Process your CSS with PostCSS. Config file support (project or theme or passed as an option).
* `resources.Minify`: Currently supports `css`, `js`, `json`, `html`, `svg`, `xml`.
* `resources.Fingerprint`: Creates a fingerprinted version of the given Resource with Subresource Integrity..
* `resources.Concat`: Concatenates a list of Resource objects. Think of this as a poor man's bundler.
* `resources.ExecuteAsTemplate`: Parses and executes the given Resource and data context (e.g. .Site) as a Go template.

Fixes #4381
Fixes #4903
Fixes #4858
2018-07-06 11:46:12 +02:00

545 lines
12 KiB
Go

// Copyright 2015 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 hugolib
import (
"errors"
"fmt"
"html/template"
"math"
"reflect"
"strings"
"github.com/gohugoio/hugo/config"
"github.com/spf13/cast"
)
// 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
}
// Len returns the number of pages in the list.
func (p Pages) Len() int {
return len(p)
}
// Len returns the number of pages in the page group.
func (psg PagesGroup) Len() int {
l := 0
for _, pg := range psg {
l += len(pg.Pages)
}
return l
}
type pagers []*Pager
var (
paginatorEmptyPages Pages
paginatorEmptyPageGroups PagesGroup
)
type paginator struct {
paginatedElements []paginatedElement
pagers
paginationURLFactory
total int
size int
source interface{}
options []interface{}
}
type paginationURLFactory func(int) string
// PageNumber returns the current page's number in the pager sequence.
func (p *Pager) PageNumber() int {
return p.number
}
// URL returns the URL to the current page.
func (p *Pager) URL() template.HTML {
return template.HTML(p.paginationURLFactory(p.PageNumber()))
}
// Pages returns the Pages on this page.
// Note: If this return a non-empty result, then PageGroups() will return empty.
func (p *Pager) Pages() Pages {
if len(p.paginatedElements) == 0 {
return paginatorEmptyPages
}
if pages, ok := p.element().(Pages); ok {
return pages
}
return paginatorEmptyPages
}
// PageGroups return Page groups for this page.
// Note: If this return non-empty result, then Pages() will return empty.
func (p *Pager) PageGroups() PagesGroup {
if len(p.paginatedElements) == 0 {
return paginatorEmptyPageGroups
}
if groups, ok := p.element().(PagesGroup); ok {
return groups
}
return paginatorEmptyPageGroups
}
func (p *Pager) element() paginatedElement {
if len(p.paginatedElements) == 0 {
return paginatorEmptyPages
}
return p.paginatedElements[p.PageNumber()-1]
}
// page returns the Page with the given index
func (p *Pager) page(index int) (*Page, error) {
if pages, ok := p.element().(Pages); ok {
if pages != nil && len(pages) > index {
return pages[index], nil
}
return nil, nil
}
// must be PagesGroup
// this construction looks clumsy, but ...
// ... it is the difference between 99.5% and 100% test coverage :-)
groups := p.element().(PagesGroup)
i := 0
for _, v := range groups {
for _, page := range v.Pages {
if i == index {
return page, nil
}
i++
}
}
return nil, nil
}
// NumberOfElements gets the number of elements on this page.
func (p *Pager) NumberOfElements() int {
return p.element().Len()
}
// HasPrev tests whether there are page(s) before the current.
func (p *Pager) HasPrev() bool {
return p.PageNumber() > 1
}
// Prev returns the pager for the previous page.
func (p *Pager) Prev() *Pager {
if !p.HasPrev() {
return nil
}
return p.pagers[p.PageNumber()-2]
}
// HasNext tests whether there are page(s) after the current.
func (p *Pager) HasNext() bool {
return p.PageNumber() < len(p.paginatedElements)
}
// Next returns the pager for the next page.
func (p *Pager) Next() *Pager {
if !p.HasNext() {
return nil
}
return p.pagers[p.PageNumber()]
}
// First returns the pager for the first page.
func (p *Pager) First() *Pager {
return p.pagers[0]
}
// Last returns the pager for the last page.
func (p *Pager) Last() *Pager {
return p.pagers[len(p.pagers)-1]
}
// Pagers returns a list of pagers that can be used to build a pagination menu.
func (p *paginator) Pagers() pagers {
return p.pagers
}
// PageSize returns the size of each paginator page.
func (p *paginator) PageSize() int {
return p.size
}
// TotalPages returns the number of pages in the paginator.
func (p *paginator) TotalPages() int {
return len(p.paginatedElements)
}
// TotalNumberOfElements returns the number of elements on all pages in this paginator.
func (p *paginator) TotalNumberOfElements() int {
return p.total
}
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
}
func splitPageGroups(pageGroups PagesGroup, size int) []paginatedElement {
type keyPage struct {
key interface{}
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 interface{}
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
}
// Paginator get this Page's main output's paginator.
func (p *Page) Paginator(options ...interface{}) (*Pager, error) {
return p.mainPageOutput.Paginator(options...)
}
// Paginator gets this PageOutput's paginator if it's already created.
// If it's not, one will be created with all pages in Data["Pages"].
func (p *PageOutput) Paginator(options ...interface{}) (*Pager, error) {
if !p.IsNode() {
return nil, fmt.Errorf("Paginators not supported for pages of type %q (%q)", p.Kind, p.title)
}
pagerSize, err := resolvePagerSize(p.s.Cfg, options...)
if err != nil {
return nil, err
}
var initError error
p.paginatorInit.Do(func() {
if p.paginator != nil {
return
}
pathDescriptor := p.targetPathDescriptor
if p.s.owner.IsMultihost() {
pathDescriptor.LangPrefix = ""
}
pagers, err := paginatePages(pathDescriptor, p.data["Pages"], pagerSize)
if err != nil {
initError = err
}
if len(pagers) > 0 {
// the rest of the nodes will be created later
p.paginator = pagers[0]
p.paginator.source = "paginator"
p.paginator.options = options
}
})
if initError != nil {
return nil, initError
}
return p.paginator, nil
}
// Paginate invokes this Page's main output's Paginate method.
func (p *Page) Paginate(seq interface{}, options ...interface{}) (*Pager, error) {
return p.mainPageOutput.Paginate(seq, options...)
}
// Paginate gets this PageOutput's paginator if it's already created.
// If it's not, one will be created with the qiven sequence.
// Note that repeated calls will return the same result, even if the sequence is different.
func (p *PageOutput) Paginate(seq interface{}, options ...interface{}) (*Pager, error) {
if !p.IsNode() {
return nil, fmt.Errorf("Paginators not supported for pages of type %q (%q)", p.Kind, p.title)
}
pagerSize, err := resolvePagerSize(p.s.Cfg, options...)
if err != nil {
return nil, err
}
var initError error
p.paginatorInit.Do(func() {
if p.paginator != nil {
return
}
pathDescriptor := p.targetPathDescriptor
if p.s.owner.IsMultihost() {
pathDescriptor.LangPrefix = ""
}
pagers, err := paginatePages(pathDescriptor, seq, pagerSize)
if err != nil {
initError = err
}
if len(pagers) > 0 {
// the rest of the nodes will be created later
p.paginator = pagers[0]
p.paginator.source = seq
p.paginator.options = options
}
})
if initError != nil {
return nil, initError
}
if p.paginator.source == "paginator" {
return nil, errors.New("a Paginator was previously built for this Node without filters; look for earlier .Paginator usage")
}
if !reflect.DeepEqual(options, p.paginator.options) || !probablyEqualPageLists(p.paginator.source, seq) {
return nil, errors.New("invoked multiple times with different arguments")
}
return p.paginator, nil
}
func resolvePagerSize(cfg config.Provider, options ...interface{}) (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 paginatePages(td targetPathDescriptor, seq interface{}, pagerSize int) (pagers, error) {
if pagerSize <= 0 {
return nil, errors.New("'paginate' configuration setting must be positive to paginate")
}
urlFactory := newPaginationURLFactory(td)
var paginator *paginator
if groups, ok := seq.(PagesGroup); ok {
paginator, _ = newPaginatorFromPageGroups(groups, pagerSize, urlFactory)
} else {
pages, err := toPages(seq)
if err != nil {
return nil, err
}
paginator, _ = newPaginatorFromPages(pages, pagerSize, urlFactory)
}
pagers := paginator.Pagers()
return pagers, nil
}
func toPages(seq interface{}) (Pages, error) {
if seq == nil {
return Pages{}, nil
}
switch seq.(type) {
case Pages:
return seq.(Pages), nil
case *Pages:
return *(seq.(*Pages)), nil
case WeightedPages:
return (seq.(WeightedPages)).Pages(), nil
case PageGroup:
return (seq.(PageGroup)).Pages, nil
default:
return nil, fmt.Errorf("unsupported type in paginate, got %T", seq)
}
}
// probablyEqual checks page lists for probable equality.
// It may return false positives.
// The motivation behind this is to avoid potential costly reflect.DeepEqual
// when "probably" is good enough.
func probablyEqualPageLists(a1 interface{}, a2 interface{}) bool {
if a1 == nil || a2 == nil {
return a1 == a2
}
t1 := reflect.TypeOf(a1)
t2 := reflect.TypeOf(a2)
if t1 != t2 {
return false
}
if g1, ok := a1.(PagesGroup); ok {
g2 := a2.(PagesGroup)
if len(g1) != len(g2) {
return false
}
if len(g1) == 0 {
return true
}
if g1.Len() != g2.Len() {
return false
}
return g1[0].Pages[0] == g2[0].Pages[0]
}
p1, err1 := toPages(a1)
p2, err2 := toPages(a2)
// probably the same wrong type
if err1 != nil && err2 != nil {
return true
}
if len(p1) != len(p2) {
return false
}
if len(p1) == 0 {
return true
}
return p1[0] == p2[0]
}
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 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 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 newPaginationURLFactory(d targetPathDescriptor) paginationURLFactory {
return func(page int) string {
pathDescriptor := d
var rel string
if page > 1 {
rel = fmt.Sprintf("/%s/%d/", d.PathSpec.PaginatePath, page)
pathDescriptor.Addends = rel
}
targetPath := createTargetPath(pathDescriptor)
targetPath = strings.TrimSuffix(targetPath, d.Type.BaseFilename())
link := d.PathSpec.PrependBasePath(targetPath)
// Note: The targetPath is massaged with MakePathSanitized
return d.PathSpec.URLizeFilename(link)
}
}