Source file based relative linking

ala GitHub repository markdown for both md files and non-md files

Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au>

helpers/content.go

@@ -43,27 +43,29 @@ var SummaryDivider = []byte("<!--more-->")
 
 // Blackfriday holds configuration values for Blackfriday rendering.
 type Blackfriday struct {
-	Smartypants     bool
-	AngledQuotes    bool
-	Fractions       bool
-	HrefTargetBlank bool
-	SmartDashes     bool
-	LatexDashes     bool
-	PlainIDAnchors  bool
-	Extensions      []string
-	ExtensionsMask  []string
+	Smartypants             bool
+	AngledQuotes            bool
+	Fractions               bool
+	HrefTargetBlank         bool
+	SmartDashes             bool
+	LatexDashes             bool
+	PlainIDAnchors          bool
+	SourceRelativeLinksEval bool
+	Extensions              []string
+	ExtensionsMask          []string
 }
 
 // NewBlackfriday creates a new Blackfriday filled with site config or some sane defaults
 func NewBlackfriday() *Blackfriday {
 	combinedParam := map[string]interface{}{
-		"smartypants":     true,
-		"angledQuotes":    false,
-		"fractions":       true,
-		"hrefTargetBlank": false,
-		"smartDashes":     true,
-		"latexDashes":     true,
-		"plainIDAnchors":  false,
+		"smartypants":         true,
+		"angledQuotes":        false,
+		"fractions":           true,
+		"hrefTargetBlank":     false,
+		"smartDashes":         true,
+		"latexDashes":         true,
+		"plainIDAnchors":      false,
+		"sourceRelativeLinks": false,
 	}
 
 	siteParam := viper.GetStringMap("blackfriday")
@@ -198,7 +200,9 @@ func GetHTMLRenderer(defaultFlags int, ctx *RenderingContext) blackfriday.Render
 	}
 
 	return &HugoHtmlRenderer{
-		blackfriday.HtmlRendererWithParameters(htmlFlags, "", "", renderParameters),
+		FileResolver: ctx.FileResolver,
+		LinkResolver: ctx.LinkResolver,
+		Renderer:     blackfriday.HtmlRendererWithParameters(htmlFlags, "", "", renderParameters),
 	}
 }
 
@@ -329,11 +333,13 @@ func ExtractTOC(content []byte) (newcontent []byte, toc []byte) {
 // RenderingContext holds contextual information, like content and configuration,
 // for a given content renderin.g
 type RenderingContext struct {
-	Content    []byte
-	PageFmt    string
-	DocumentID string
-	Config     *Blackfriday
-	configInit sync.Once
+	Content      []byte
+	PageFmt      string
+	DocumentID   string
+	Config       *Blackfriday
+	FileResolver FileResolverFunc
+	LinkResolver LinkResolverFunc
+	configInit   sync.Once
 }
 
 func (c *RenderingContext) getConfig() *Blackfriday {

helpers/content_renderer.go

@@ -19,12 +19,18 @@ import (
 
 	"github.com/miekg/mmark"
 	"github.com/russross/blackfriday"
+	jww "github.com/spf13/jwalterweatherman"
 	"github.com/spf13/viper"
 )
 
+type LinkResolverFunc func(ref string) (string, error)
+type FileResolverFunc func(ref string) (string, error)
+
 // Wraps a blackfriday.Renderer, typically a blackfriday.Html
 // Enabling Hugo to customise the rendering experience
 type HugoHtmlRenderer struct {
+	FileResolver FileResolverFunc
+	LinkResolver LinkResolverFunc
 	blackfriday.Renderer
 }
 
@@ -38,6 +44,33 @@ func (renderer *HugoHtmlRenderer) BlockCode(out *bytes.Buffer, text []byte, lang
 	}
 }
 
+func (renderer *HugoHtmlRenderer) Link(out *bytes.Buffer, link []byte, title []byte, content []byte) {
+	if renderer.LinkResolver == nil || bytes.HasPrefix(link, []byte("{@{@HUGOSHORTCODE")) {
+		// Use the blackfriday built in Link handler
+		renderer.Renderer.Link(out, link, title, content)
+	} else {
+		newLink, err := renderer.LinkResolver(string(link))
+		if err != nil {
+			newLink = string(link)
+			jww.ERROR.Printf("LinkResolver: %s", err)
+		}
+		renderer.Renderer.Link(out, []byte(newLink), title, content)
+	}
+}
+func (renderer *HugoHtmlRenderer) Image(out *bytes.Buffer, link []byte, title []byte, alt []byte) {
+	if renderer.FileResolver == nil || bytes.HasPrefix(link, []byte("{@{@HUGOSHORTCODE")) {
+		// Use the blackfriday built in Image handler
+		renderer.Renderer.Image(out, link, title, alt)
+	} else {
+		newLink, err := renderer.FileResolver(string(link))
+		if err != nil {
+			newLink = string(link)
+			jww.ERROR.Printf("FileResolver: %s", err)
+		}
+		renderer.Renderer.Image(out, []byte(newLink), title, alt)
+	}
+}
+
 // Wraps a mmark.Renderer, typically a mmark.html
 // Enabling Hugo to customise the rendering experience
 type HugoMmarkHtmlRenderer struct {

hugolib/page.go

@@ -234,14 +234,34 @@ func (p *Page) setSummary() {
 }
 
 func (p *Page) renderBytes(content []byte) []byte {
+	var fn helpers.LinkResolverFunc
+	var fileFn helpers.FileResolverFunc
+	if p.getRenderingConfig().SourceRelativeLinksEval {
+		fn = func(ref string) (string, error) {
+			return p.Node.Site.GitHub(ref, p)
+		}
+		fileFn = func(ref string) (string, error) {
+			return p.Node.Site.GitHubFileLink(ref, p)
+		}
+	}
 	return helpers.RenderBytes(
 		&helpers.RenderingContext{Content: content, PageFmt: p.guessMarkupType(),
-			DocumentID: p.UniqueID(), Config: p.getRenderingConfig()})
+			DocumentID: p.UniqueID(), Config: p.getRenderingConfig(), LinkResolver: fn, FileResolver: fileFn})
 }
 
 func (p *Page) renderContent(content []byte) []byte {
+	var fn helpers.LinkResolverFunc
+	var fileFn helpers.FileResolverFunc
+	if p.getRenderingConfig().SourceRelativeLinksEval {
+		fn = func(ref string) (string, error) {
+			return p.Node.Site.GitHub(ref, p)
+		}
+		fileFn = func(ref string) (string, error) {
+			return p.Node.Site.GitHubFileLink(ref, p)
+		}
+	}
 	return helpers.RenderBytesWithTOC(&helpers.RenderingContext{Content: content, PageFmt: p.guessMarkupType(),
-		DocumentID: p.UniqueID(), Config: p.getRenderingConfig()})
+		DocumentID: p.UniqueID(), Config: p.getRenderingConfig(), LinkResolver: fn, FileResolver: fileFn})
 }
 
 func (p *Page) getRenderingConfig() *helpers.Blackfriday {

hugolib/site.go

@@ -100,7 +100,7 @@ type SiteInfo struct {
 	Social                SiteSocial
 	Sections              Taxonomy
 	Pages                 *Pages
-	Files                 []*source.File
+	Files                 *[]*source.File
 	Menus                 *Menus
 	Hugo                  *HugoInfo
 	Title                 string
@@ -217,6 +217,166 @@ func (s *SiteInfo) RelRef(ref string, page *Page) (string, error) {
 	return s.refLink(ref, page, true)
 }
 
+func (s *SiteInfo) GitHub(ref string, page *Page) (string, error) {
+	return s.githubLink(ref, page, true)
+}
+
+func (s *SiteInfo) githubLink(ref string, currentPage *Page, relative bool) (string, error) {
+	var refURL *url.URL
+	var err error
+
+	// TODO can I make this a param to `hugo --use-github-links=/docs`?
+	// SVEN: add more tests - the prefix might be a real dir inside tho - add some pages that have it as a legitimate path
+	repositoryPathPrefix := "/docs"
+
+	refURL, err = url.Parse(strings.TrimPrefix(ref, repositoryPathPrefix))
+	if err != nil {
+		return "", err
+	}
+
+	if refURL.Scheme != "" {
+		// TODO: consider looking for http(s?)://github.com/user/project/prefix and replacing it - tho this may be intentional, so idk
+		//return "", fmt.Errorf("Not a plain filepath link (%s)", ref)
+		// Treat this as not an error, as the link is used as-is
+		return ref, nil
+	}
+
+	var target *Page
+	var link string
+
+	if refURL.Path != "" {
+		refPath := filepath.Clean(filepath.FromSlash(refURL.Path))
+
+		if strings.IndexRune(refPath, os.PathSeparator) == 0 { // filepath.IsAbs fails to me.
+			refPath = refPath[1:]
+		} else {
+			if currentPage != nil {
+				refPath = filepath.Join(currentPage.Source.Dir(), refURL.Path)
+			}
+		}
+
+		for _, page := range []*Page(*s.Pages) {
+			if page.Source.Path() == refPath {
+				target = page
+				break
+			}
+		}
+		// need to exhaust the test, then try with the others :/
+		// if the refPath doesn't end in a filename with extension `.md`, then try with `.md` , and then `/index.md`
+		mdPath := strings.TrimSuffix(refPath, string(os.PathSeparator)) + ".md"
+		for _, page := range []*Page(*s.Pages) {
+			if page.Source.Path() == mdPath {
+				target = page
+				break
+			}
+		}
+		indexPath := filepath.Join(refPath, "index.md")
+		for _, page := range []*Page(*s.Pages) {
+			if page.Source.Path() == indexPath {
+				target = page
+				break
+			}
+		}
+
+		if target == nil {
+			return "", fmt.Errorf("No page found for \"%s\" on page \"%s\".\n", ref, currentPage.Source.Path())
+		}
+
+		// SVEN: look at filepath.Rel() it might help, got the rel/non-rel url's (dangerous tho)
+		if relative {
+			link, err = target.RelPermalink()
+		} else {
+			link, err = target.Permalink()
+		}
+
+		if err != nil {
+			return "", err
+		}
+	}
+
+	// SVEN: add tests for github style relative fragments
+	if refURL.Fragment != "" {
+		link = link + "#" + refURL.Fragment
+
+		if refURL.Path != "" && target != nil && !target.getRenderingConfig().PlainIDAnchors {
+			link = link + ":" + target.UniqueID()
+		} else if currentPage != nil && !currentPage.getRenderingConfig().PlainIDAnchors {
+			link = link + ":" + currentPage.UniqueID()
+		}
+	}
+
+	return link, nil
+}
+
+func (s *SiteInfo) GitHubFileLink(ref string, page *Page) (string, error) {
+	return s.githubFileLink(ref, page, false)
+}
+
+// for non-pages in the site tree
+func (s *SiteInfo) githubFileLink(ref string, currentPage *Page, relative bool) (string, error) {
+	var refURL *url.URL
+	var err error
+
+	// TODO can I make this a param to `hugo --use-github-links=/docs`?
+	// SVEN: add more tests - the prefix might be a real dir inside tho - add some pages that have it as a legitimate path
+	repositoryPathPrefix := "/docs"
+
+	refURL, err = url.Parse(strings.TrimPrefix(ref, repositoryPathPrefix))
+	if err != nil {
+		return "", err
+	}
+
+	if refURL.Scheme != "" {
+		// TODO: consider looking for http(s?)://github.com/user/project/prefix and replacing it - tho this may be intentional, so idk
+		//return "", fmt.Errorf("Not a plain filepath link (%s)", ref)
+		// Treat this as not an error, as the link is used as-is
+		return ref, nil
+	}
+
+	var target *source.File
+	var link string
+
+	if refURL.Path != "" {
+		refPath := filepath.Clean(filepath.FromSlash(refURL.Path))
+
+		if strings.IndexRune(refPath, os.PathSeparator) == 0 { // filepath.IsAbs fails to me.
+			refPath = refPath[1:]
+		} else {
+			if currentPage != nil {
+				refPath = filepath.Join(currentPage.Source.Dir(), refURL.Path)
+			}
+		}
+
+		for _, file := range []*source.File(*s.Files) {
+			if file.Path() == refPath {
+				target = file
+				break
+			}
+		}
+
+		if target == nil {
+			return "", fmt.Errorf("No file found for \"%s\" on page \"%s\".\n", ref, currentPage.Source.Path())
+		}
+
+		link = target.Path()
+		// SVEN: look at filepath.Rel() it might help, got the rel/non-rel url's (dangerous tho)
+		// SVEN: reconsider the fact I hardcoded the `relative` bool in both github resolvers
+		if relative {
+			return "./" + filepath.ToSlash(link), nil
+		} else {
+			return "/" + filepath.ToSlash(link), nil
+		}
+
+		if err != nil {
+			return "", err
+		}
+
+		return link, nil
+	}
+
+	return "", fmt.Errorf("failed to find a file to match \"%s\" on page \"%s\"", ref, currentPage.Source.Path())
+}
+
 func (s *SiteInfo) addToPaginationPageCount(cnt uint64) {
 	atomic.AddUint64(&s.paginationPageCount, cnt)
 }
@@ -479,6 +639,7 @@ func (s *Site) initializeSiteInfo() {
 		canonifyURLs:          viper.GetBool("CanonifyURLs"),
 		preserveTaxonomyNames: viper.GetBool("PreserveTaxonomyNames"),
 		Pages:      &s.Pages,
+		Files:      &s.Files,
 		Menus:      &s.Menus,
 		Params:     params,
 		Permalinks: permalinks,
@@ -1395,6 +1556,7 @@ func (s *Site) Stats() {
 	jww.FEEDBACK.Println(s.draftStats())
 	jww.FEEDBACK.Println(s.futureStats())
 	jww.FEEDBACK.Printf("%d pages created\n", len(s.Pages))
+	jww.FEEDBACK.Printf("%d non-page files copied\n", len(s.Files))
 	jww.FEEDBACK.Printf("%d paginator pages created\n", s.Info.paginationPageCount)
 	taxonomies := viper.GetStringMapString("Taxonomies")