Use date from post filename in permalink

collection/collection.go

@@ -22,6 +22,7 @@ type Collection struct {
 // Site is the interface a site provides to collections it contains.
 type Site interface {
 	Config() *config.Config
+	Exclude(string) bool
 	RenderingPipeline() pipelines.PipelineInterface
 	OutputExt(pathname string) string
 }
@@ -36,22 +37,11 @@ func New(s Site, name string, metadata map[string]interface{}) *Collection {
 	}
 }
 
-// AbsDir is in the page.Container interface.
+// AbsDir returns the absolute path to the collection directory.
 func (c *Collection) AbsDir() string {
 	return filepath.Join(c.config.SourceDir(), c.PathPrefix())
 }
 
-// Config is in the page.Container interface.
-func (c *Collection) Config() *config.Config {
-	return c.config
-}
-
-// OutputExt is in the page.Container interface.
-func (c *Collection) OutputExt(pathname string) string {
-	return c.site.OutputExt(pathname)
-}
-
-// PathPrefix is in the page.Container interface.
 // PathPrefix returns the collection's directory prefix, e.g. "_posts/"
 func (c *Collection) PathPrefix() string { return filepath.FromSlash("_" + c.Name + "/") }
 

collection/read.go

@@ -4,7 +4,6 @@ import (
 	"os"
 	"path/filepath"
 	"sort"
-	"strings"
 
 	"github.com/osteele/gojekyll/pages"
 	"github.com/osteele/gojekyll/templates"
@@ -13,8 +12,26 @@ import (
 
 const draftsPath = "_drafts"
 
-// ScanDirectory scans the file system for collection pages, and adds them to c.Pages.
-func (c *Collection) ScanDirectory(dirname string) error {
+// ReadPages scans the file system for collection pages, and adds them to c.Pages.
+func (c *Collection) ReadPages() error {
+	if c.IsPostsCollection() && c.config.Drafts {
+		if err := c.scanDirectory(draftsPath); err != nil {
+			return err
+		}
+	}
+	if err := c.scanDirectory(c.PathPrefix()); err != nil {
+		return err
+	}
+	if c.IsPostsCollection() {
+		sort.Sort(pagesByDate{c.pages})
+	}
+	return nil
+}
+
+// scanDirectory scans the file system for collection pages, and adds them to c.Pages.
+//
+// This function is distinct from ReadPages so that the posts collection can call it twice.
+func (c *Collection) scanDirectory(dirname string) error {
 	sitePath := c.config.Source
 	pageDefaults := map[string]interface{}{
 		"collection": c.Name,
@@ -29,35 +46,18 @@ func (c *Collection) ScanDirectory(dirname string) error {
 		}
 		relname := utils.MustRel(sitePath, filename)
 		switch {
-		case strings.HasPrefix(filepath.Base(relname), "."):
-			return nil
-		case err != nil:
-			return err
 		case info.IsDir():
 			return nil
+		case c.site.Exclude(relname):
+			return nil
+		default:
+			fm := templates.MergeVariableMaps(pageDefaults, c.config.GetFrontMatterDefaults(c.Name, relname))
+			return c.readFile(filename, relname, fm)
 		}
-		fm := templates.MergeVariableMaps(pageDefaults, c.config.GetFrontMatterDefaults(c.Name, relname))
-		return c.readFile(filename, relname, fm)
 	}
 	return filepath.Walk(filepath.Join(sitePath, dirname), walkFn)
 }
 
-// ReadPages scans the file system for collection pages, and adds them to c.Pages.
-func (c *Collection) ReadPages() error {
-	if c.IsPostsCollection() && c.config.Drafts {
-		if err := c.ScanDirectory(draftsPath); err != nil {
-			return err
-		}
-	}
-	if err := c.ScanDirectory(c.PathPrefix()); err != nil {
-		return err
-	}
-	if c.IsPostsCollection() {
-		sort.Sort(pagesByDate{c.pages})
-	}
-	return nil
-}
-
 // readFile mutates fm.
 func (c *Collection) readFile(abs string, rel string, fm map[string]interface{}) error {
 	strategy := c.strategy()

pages/page.go

@@ -71,12 +71,13 @@ func (p *page) FrontMatter() map[string]interface{} {
 }
 
 // PostDate is part of the Page interface.
-func (p *page) PostDate() time.Time {
-	switch value := p.frontMatter["date"].(type) {
+// FIXME move this back to Page interface, or re-work this entirely.
+func (f *file) PostDate() time.Time {
+	switch value := f.frontMatter["date"].(type) {
 	case time.Time:
 		return value
 	case string:
-		t, err := evaluator.ParseTime(value)
+		t, err := evaluator.ParseDate(value)
 		if err == nil {
 			return t
 		}

pages/permalinks.go

@@ -41,13 +41,18 @@ var templateVariableMatcher = regexp.MustCompile(`:\w+\b`)
 // See https://jekyllrb.com/docs/permalinks/#template-variables
 func (f *file) permalinkVariables() map[string]string {
 	var (
-		relpath  = f.relpath
-		root     = utils.TrimExt(relpath)
-		name     = filepath.Base(root)
-		fm       = f.frontMatter
-		bindings = templates.VariableMap(fm)
-		slug     = bindings.String("slug", utils.Slugify(name))
+		relpath   = f.relpath
+		root      = utils.TrimExt(relpath)
+		name      = filepath.Base(root)
+		fm        = f.frontMatter
+		bindings  = templates.VariableMap(fm)
+		slug      = bindings.String("slug", utils.Slugify(name))
+		date      = f.fileModTime
+		dateField = bindings.String("date", "")
 	)
+	if dateField != "" {
+		date = f.PostDate()
+	}
 	vars := map[string]string{
 		"categories": strings.Join(f.Categories(), "/"),
 		"collection": bindings.String("collection", ""),
@@ -60,7 +65,7 @@ func (f *file) permalinkVariables() map[string]string {
 		"y_day":      strconv.Itoa(f.fileModTime.YearDay()),
 	}
 	for k, v := range permalinkDateVariables {
-		vars[k] = f.fileModTime.Format(v)
+		vars[k] = date.Format(v)
 	}
 	return vars
 }

site/site.go

@@ -190,10 +190,10 @@ func (s *Site) Exclude(path string) bool {
 	exclusionMap := utils.StringArrayToMap(s.config.Exclude)
 	base := filepath.Base(path)
 	switch {
-	case inclusionMap[path]:
-		return false
 	case path == ".":
 		return false
+	case inclusionMap[path]:
+		return false
 	case exclusionMap[path]:
 		return true
 	case strings.HasPrefix(base, "."), strings.HasPrefix(base, "_"):