github.com/linchen2chris/hugo@v0.0.0-20230307053224-cec209389705/resources/page/page_lazy_contentprovider.go (about)

     1  // Copyright 2019 The Hugo Authors. All rights reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  // http://www.apache.org/licenses/LICENSE-2.0
     7  //
     8  // Unless required by applicable law or agreed to in writing, software
     9  // distributed under the License is distributed on an "AS IS" BASIS,
    10  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package page
    15  
    16  import (
    17  	"context"
    18  	"html/template"
    19  
    20  	"github.com/gohugoio/hugo/lazy"
    21  	"github.com/gohugoio/hugo/markup/converter"
    22  	"github.com/gohugoio/hugo/markup/tableofcontents"
    23  )
    24  
    25  // OutputFormatContentProvider represents the method set that is "outputFormat aware" and that we
    26  // provide lazy initialization for in case they get invoked outside of their normal rendering context, e.g. via .Translations.
    27  // Note that this set is currently not complete, but should cover the most common use cases.
    28  // For the others, the implementation will be from the page.NoopPage.
    29  type OutputFormatContentProvider interface {
    30  	OutputFormatPageContentProvider
    31  
    32  	// for internal use.
    33  	ContentRenderer
    34  }
    35  
    36  // OutputFormatPageContentProvider holds the exported methods from Page that are "outputFormat aware".
    37  type OutputFormatPageContentProvider interface {
    38  	ContentProvider
    39  	TableOfContentsProvider
    40  	PageRenderProvider
    41  }
    42  
    43  // LazyContentProvider initializes itself when read. Each method of the
    44  // ContentProvider interface initializes a content provider and shares it
    45  // with other methods.
    46  //
    47  // Used in cases where we cannot guarantee whether the content provider
    48  // will be needed. Must create via NewLazyContentProvider.
    49  type LazyContentProvider struct {
    50  	init *lazy.Init
    51  	cp   OutputFormatContentProvider
    52  }
    53  
    54  // NewLazyContentProvider returns a LazyContentProvider initialized with
    55  // function f. The resulting LazyContentProvider calls f in order to
    56  // retrieve a ContentProvider
    57  func NewLazyContentProvider(f func() (OutputFormatContentProvider, error)) *LazyContentProvider {
    58  	lcp := LazyContentProvider{
    59  		init: lazy.New(),
    60  		cp:   NopCPageContentRenderer,
    61  	}
    62  	lcp.init.Add(func(context.Context) (any, error) {
    63  		cp, err := f()
    64  		if err != nil {
    65  			return nil, err
    66  		}
    67  		lcp.cp = cp
    68  		return nil, nil
    69  	})
    70  	return &lcp
    71  }
    72  
    73  func (lcp *LazyContentProvider) Reset() {
    74  	lcp.init.Reset()
    75  }
    76  
    77  func (lcp *LazyContentProvider) TableOfContents(ctx context.Context) template.HTML {
    78  	lcp.init.Do(ctx)
    79  	return lcp.cp.TableOfContents(ctx)
    80  
    81  }
    82  
    83  func (lcp *LazyContentProvider) Fragments(ctx context.Context) *tableofcontents.Fragments {
    84  	lcp.init.Do(ctx)
    85  	return lcp.cp.Fragments(ctx)
    86  }
    87  
    88  func (lcp *LazyContentProvider) Content(ctx context.Context) (any, error) {
    89  	lcp.init.Do(ctx)
    90  	return lcp.cp.Content(ctx)
    91  }
    92  
    93  func (lcp *LazyContentProvider) Plain(ctx context.Context) string {
    94  	lcp.init.Do(ctx)
    95  	return lcp.cp.Plain(ctx)
    96  }
    97  
    98  func (lcp *LazyContentProvider) PlainWords(ctx context.Context) []string {
    99  	lcp.init.Do(ctx)
   100  	return lcp.cp.PlainWords(ctx)
   101  }
   102  
   103  func (lcp *LazyContentProvider) Summary(ctx context.Context) template.HTML {
   104  	lcp.init.Do(ctx)
   105  	return lcp.cp.Summary(ctx)
   106  }
   107  
   108  func (lcp *LazyContentProvider) Truncated(ctx context.Context) bool {
   109  	lcp.init.Do(ctx)
   110  	return lcp.cp.Truncated(ctx)
   111  }
   112  
   113  func (lcp *LazyContentProvider) FuzzyWordCount(ctx context.Context) int {
   114  	lcp.init.Do(ctx)
   115  	return lcp.cp.FuzzyWordCount(ctx)
   116  }
   117  
   118  func (lcp *LazyContentProvider) WordCount(ctx context.Context) int {
   119  	lcp.init.Do(ctx)
   120  	return lcp.cp.WordCount(ctx)
   121  }
   122  
   123  func (lcp *LazyContentProvider) ReadingTime(ctx context.Context) int {
   124  	lcp.init.Do(ctx)
   125  	return lcp.cp.ReadingTime(ctx)
   126  }
   127  
   128  func (lcp *LazyContentProvider) Len(ctx context.Context) int {
   129  	lcp.init.Do(ctx)
   130  	return lcp.cp.Len(ctx)
   131  }
   132  
   133  func (lcp *LazyContentProvider) Render(ctx context.Context, layout ...string) (template.HTML, error) {
   134  	lcp.init.Do(context.TODO())
   135  	return lcp.cp.Render(ctx, layout...)
   136  }
   137  
   138  func (lcp *LazyContentProvider) RenderString(ctx context.Context, args ...any) (template.HTML, error) {
   139  	lcp.init.Do(ctx)
   140  	return lcp.cp.RenderString(ctx, args...)
   141  }
   142  
   143  func (lcp *LazyContentProvider) ParseAndRenderContent(ctx context.Context, content []byte, renderTOC bool) (converter.ResultRender, error) {
   144  	lcp.init.Do(ctx)
   145  	return lcp.cp.ParseAndRenderContent(ctx, content, renderTOC)
   146  }
   147  
   148  func (lcp *LazyContentProvider) ParseContent(ctx context.Context, content []byte) (converter.ResultParse, bool, error) {
   149  	lcp.init.Do(ctx)
   150  	return lcp.cp.ParseContent(ctx, content)
   151  }
   152  func (lcp *LazyContentProvider) RenderContent(ctx context.Context, content []byte, doc any) (converter.ResultRender, bool, error) {
   153  	lcp.init.Do(ctx)
   154  	return lcp.cp.RenderContent(ctx, content, doc)
   155  }