hugo/resources/page/pages.go

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// 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 (
"fmt"
"math/rand"
"github.com/gohugoio/hugo/compare"
"github.com/gohugoio/hugo/resources/resource"
)
var (
_ resource.ResourcesConverter = Pages{}
_ compare.ProbablyEqer = Pages{}
)
// Pages is a slice of pages. This is the most common list type in Hugo.
type Pages []Page
func (ps Pages) String() string {
return fmt.Sprintf("Pages(%d)", len(ps))
}
// Used in tests.
func (ps Pages) shuffle() {
for i := range ps {
j := rand.Intn(i + 1)
ps[i], ps[j] = ps[j], ps[i]
}
}
// ToResources wraps resource.ResourcesConverter
func (pages Pages) ToResources() resource.Resources {
r := make(resource.Resources, len(pages))
for i, p := range pages {
r[i] = p
}
return r
}
// ToPages tries to convert seq into Pages.
func ToPages(seq interface{}) (Pages, error) {
if seq == nil {
return Pages{}, nil
}
switch v := seq.(type) {
case Pages:
return v, nil
case *Pages:
return *(v), nil
case WeightedPages:
return v.Pages(), nil
case PageGroup:
return v.Pages, nil
case []Page:
pages := make(Pages, len(v))
for i, vv := range v {
pages[i] = vv
}
return pages, nil
case []interface{}:
pages := make(Pages, len(v))
success := true
for i, vv := range v {
p, ok := vv.(Page)
if !ok {
success = false
break
}
pages[i] = p
}
if success {
return pages, nil
}
}
return nil, fmt.Errorf("cannot convert type %T to Pages", seq)
}
func (p Pages) Group(key interface{}, in interface{}) (interface{}, error) {
pages, err := ToPages(in)
if err != nil {
return nil, err
}
return PageGroup{Key: key, Pages: pages}, nil
}
// Len returns the number of pages in the list.
func (p Pages) Len() int {
return len(p)
}
// ProbablyEq wraps comare.ProbablyEqer
func (pages Pages) ProbablyEq(other interface{}) bool {
otherPages, ok := other.(Pages)
if !ok {
return false
}
if len(pages) != len(otherPages) {
return false
}
step := 1
for i := 0; i < len(pages); i += step {
if !pages[i].Eq(otherPages[i]) {
return false
}
if i > 50 {
// This is most likely the same.
step = 50
}
}
return true
}
func (ps Pages) removeFirstIfFound(p Page) Pages {
ii := -1
for i, pp := range ps {
if p.Eq(pp) {
ii = i
break
}
}
if ii != -1 {
ps = append(ps[:ii], ps[ii+1:]...)
}
return ps
}
// PagesFactory somehow creates some Pages.
// We do a lot of lazy Pages initialization in Hugo, so we need a type.
type PagesFactory func() Pages