ref: 02eaddc2fbe92c26e67d9f82dd9aabecbbf2106c
dir: /hugolib/page_output.go/
// Copyright 2017 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 (
"fmt"
"html/template"
"os"
"strings"
"sync"
bp "github.com/gohugoio/hugo/bufferpool"
"github.com/gohugoio/hugo/tpl"
"github.com/gohugoio/hugo/resources/resource"
"github.com/gohugoio/hugo/media"
"github.com/gohugoio/hugo/output"
)
// PageOutput represents one of potentially many output formats of a given
// Page.
type PageOutput struct {
*Page
// Pagination
paginator *Pager
paginatorInit sync.Once
// Page output specific resources
resources resource.Resources
resourcesInit sync.Once
// Keep this to create URL/path variations, i.e. paginators.
targetPathDescriptor targetPathDescriptor
outputFormat output.Format
}
func (p *PageOutput) targetPath(addends ...string) (string, error) {
tp, err := p.createTargetPath(p.outputFormat, false, addends...)
if err != nil {
return "", err
}
return tp, nil
}
func newPageOutput(p *Page, createCopy, initContent bool, f output.Format) (*PageOutput, error) {
// TODO(bep) This is only needed for tests and we should get rid of it.
if p.targetPathDescriptorPrototype == nil {
if err := p.initPaths(); err != nil {
return nil, err
}
}
if createCopy {
p = p.copy(initContent)
}
td, err := p.createTargetPathDescriptor(f)
if err != nil {
return nil, err
}
return &PageOutput{
Page: p,
outputFormat: f,
targetPathDescriptor: td,
}, nil
}
// copy creates a copy of this PageOutput with the lazy sync.Once vars reset
// so they will be evaluated again, for word count calculations etc.
func (p *PageOutput) copyWithFormat(f output.Format, initContent bool) (*PageOutput, error) {
c, err := newPageOutput(p.Page, true, initContent, f)
if err != nil {
return nil, err
}
c.paginator = p.paginator
return c, nil
}
func (p *PageOutput) copy() (*PageOutput, error) {
return p.copyWithFormat(p.outputFormat, false)
}
func (p *PageOutput) layouts(layouts ...string) ([]string, error) {
if len(layouts) == 0 && p.selfLayout != "" {
return []string{p.selfLayout}, nil
}
layoutDescriptor := p.layoutDescriptor
if len(layouts) > 0 {
layoutDescriptor.Layout = layouts[0]
layoutDescriptor.LayoutOverride = true
}
return p.s.layoutHandler.For(
layoutDescriptor,
p.outputFormat)
}
func (p *PageOutput) Render(layout ...string) template.HTML {
l, err := p.layouts(layout...)
if err != nil {
p.s.DistinctErrorLog.Printf("in .Render: Failed to resolve layout %q for page %q", layout, p.pathOrTitle())
return ""
}
for _, layout := range l {
templ, found := p.s.Tmpl.Lookup(layout)
if !found {
// This is legacy from when we had only one output format and
// HTML templates only. Some have references to layouts without suffix.
// We default to good old HTML.
templ, found = p.s.Tmpl.Lookup(layout + ".html")
}
if templ != nil {
res, err := executeToString(templ, p)
if err != nil {
p.s.DistinctErrorLog.Printf("in .Render: Failed to execute template %q: %s", layout, err)
return template.HTML("")
}
return template.HTML(res)
}
}
return ""
}
func executeToString(templ tpl.Template, data interface{}) (string, error) {
b := bp.GetBuffer()
defer bp.PutBuffer(b)
if err := templ.Execute(b, data); err != nil {
return "", err
}
return b.String(), nil
}
func (p *Page) Render(layout ...string) template.HTML {
if p.mainPageOutput == nil {
panic(fmt.Sprintf("programming error: no mainPageOutput for %q", p.Path()))
}
return p.mainPageOutput.Render(layout...)
}
// OutputFormats holds a list of the relevant output formats for a given resource.
type OutputFormats []*OutputFormat
// OutputFormat links to a representation of a resource.
type OutputFormat struct {
// Rel constains a value that can be used to construct a rel link.
// This is value is fetched from the output format definition.
// Note that for pages with only one output format,
// this method will always return "canonical".
// As an example, the AMP output format will, by default, return "amphtml".
//
// See:
// https://www.ampproject.org/docs/guides/deploy/discovery
//
// Most other output formats will have "alternate" as value for this.
Rel string
// It may be tempting to export this, but let us hold on to that horse for a while.
f output.Format
p *Page
}
// Name returns this OutputFormat's name, i.e. HTML, AMP, JSON etc.
func (o OutputFormat) Name() string {
return o.f.Name
}
// MediaType returns this OutputFormat's MediaType (MIME type).
func (o OutputFormat) MediaType() media.Type {
return o.f.MediaType
}
// OutputFormats gives the output formats for this Page.
func (p *Page) OutputFormats() OutputFormats {
var o OutputFormats
for _, f := range p.outputFormats {
o = append(o, newOutputFormat(p, f))
}
return o
}
func newOutputFormat(p *Page, f output.Format) *OutputFormat {
rel := f.Rel
isCanonical := len(p.outputFormats) == 1
if isCanonical {
rel = "canonical"
}
return &OutputFormat{Rel: rel, f: f, p: p}
}
// AlternativeOutputFormats gives the alternative output formats for this PageOutput.
// Note that we use the term "alternative" and not "alternate" here, as it
// does not necessarily replace the other format, it is an alternative representation.
func (p *PageOutput) AlternativeOutputFormats() (OutputFormats, error) {
var o OutputFormats
for _, of := range p.OutputFormats() {
if of.f.NotAlternative || of.f.Name == p.outputFormat.Name {
continue
}
o = append(o, of)
}
return o, nil
}
// deleteResource removes the resource from this PageOutput and the Page. They will
// always be of the same length, but may contain different elements.
func (p *PageOutput) deleteResource(i int) {
p.resources = append(p.resources[:i], p.resources[i+1:]...)
p.Page.Resources = append(p.Page.Resources[:i], p.Page.Resources[i+1:]...)
}
func (p *PageOutput) Resources() resource.Resources {
p.resourcesInit.Do(func() {
// If the current out shares the same path as the main page output, we reuse
// the resource set. For the "amp" use case, we need to clone them with new
// base folder.
ff := p.outputFormats[0]
if p.outputFormat.Path == ff.Path {
p.resources = p.Page.Resources
return
}
// Clone it with new base.
resources := make(resource.Resources, len(p.Page.Resources))
for i, r := range p.Page.Resources {
if c, ok := r.(resource.Cloner); ok {
// Clone the same resource with a new target.
resources[i] = c.WithNewBase(p.outputFormat.Path)
} else {
resources[i] = r
}
}
p.resources = resources
})
return p.resources
}
func (p *PageOutput) renderResources() error {
for i, r := range p.Resources() {
src, ok := r.(resource.Source)
if !ok {
// Pages gets rendered with the owning page.
continue
}
if err := src.Publish(); err != nil {
if os.IsNotExist(err) {
// The resource has been deleted from the file system.
// This should be extremely rare, but can happen on live reload in server
// mode when the same resource is member of different page bundles.
p.deleteResource(i)
} else {
p.s.Log.ERROR.Printf("Failed to publish Resource for page %q: %s", p.pathOrTitle(), err)
}
} else {
p.s.PathSpec.ProcessingStats.Incr(&p.s.PathSpec.ProcessingStats.Files)
}
}
return nil
}
// AlternativeOutputFormats is only available on the top level rendering
// entry point, and not inside range loops on the Page collections.
// This method is just here to inform users of that restriction.
func (p *Page) AlternativeOutputFormats() (OutputFormats, error) {
return nil, fmt.Errorf("AlternativeOutputFormats only available from the top level template context for page %q", p.Path())
}
// Get gets a OutputFormat given its name, i.e. json, html etc.
// It returns nil if not found.
func (o OutputFormats) Get(name string) *OutputFormat {
for _, f := range o {
if strings.EqualFold(f.f.Name, name) {
return f
}
}
return nil
}
// Permalink returns the absolute permalink to this output format.
func (o *OutputFormat) Permalink() string {
rel := o.p.createRelativePermalinkForOutputFormat(o.f)
perm, _ := o.p.s.permalinkForOutputFormat(rel, o.f)
return perm
}
// RelPermalink returns the relative permalink to this output format.
func (o *OutputFormat) RelPermalink() string {
rel := o.p.createRelativePermalinkForOutputFormat(o.f)
return o.p.s.PathSpec.PrependBasePath(rel, false)
}