Implement tree generation

README.md

@@ -1,7 +1,16 @@
 # mycorrhiza wiki
 A wiki engine inspired by fungi. Not production-ready.
 
-Current version: 0.7 (or more?)
+This branch is devoted to version 0.8.
+* [ ] Tree generation
+  * [x] Basic generation
+  * [ ] Generation that takes non-existent hyphae into account¹
+* [ ] History
+  * [ ] Saving all changes to git
+  * [ ] Make it possible to see any previous version
+  * [ ] A nice UI for that
+
+¹ Current algorithm won't detect `a/b/c` as a child of `a` if `a/b` does not exist.
 
 ## Current features
 * Edit pages through html forms

http_readers.go

@@ -8,6 +8,7 @@ import (
 	"os"
 
 	"github.com/bouncepaw/mycorrhiza/gemtext"
+	"github.com/bouncepaw/mycorrhiza/tree"
 )
 
 func init() {
@@ -70,7 +71,7 @@ func handlerPage(w http.ResponseWriter, rq *http.Request) {
 				%[2]s
 				%[3]s
 			</article>
-			<hr>
+			<hr/>
 			<form action="/upload-binary/%[1]s"
 			      method="post" enctype="multipart/form-data">
 				<label for="upload-binary__input">Upload new binary part</label>
@@ -78,8 +79,15 @@ func handlerPage(w http.ResponseWriter, rq *http.Request) {
 				<input type="file" id="upload-binary__input" name="binary"/>
 				<input type="submit"/>
 			</form>
+			<hr/>
+			<aside>
+				%[4]s
+			</aside>
 		</main>
-`, hyphaName, naviTitle(hyphaName), contents)
+`, hyphaName,
+		naviTitle(hyphaName),
+		contents,
+		tree.TreeAsHtml(hyphaName, IterateHyphaNamesWith))
 	w.Header().Set("Content-Type", "text/html;charset=utf-8")
 	w.WriteHeader(http.StatusOK)
 	w.Write([]byte(base(hyphaName, form)))

main.go

@@ -19,6 +19,13 @@ var HyphaPattern = regexp.MustCompile(`[^?!:#@><*|"\'&%]+`)
 // HyphaStorage is a mapping between canonical hypha names and their meta information.
 var HyphaStorage = make(map[string]*HyphaData)
 
+// IterateHyphaNamesWith is a closure to be passed to subpackages to let them iterate all hypha names read-only.
+func IterateHyphaNamesWith(f func(string)) {
+	for hyphaName, _ := range HyphaStorage {
+		f(hyphaName)
+	}
+}
+
 // HttpErr is used by many handlers to signal errors in a compact way.
 func HttpErr(w http.ResponseWriter, status int, name, title, errMsg string) {
 	log.Println(errMsg, "for", name)

tree/tree.go

@@ -0,0 +1,89 @@
+package tree
+
+import (
+	"fmt"
+	"path"
+	"sort"
+	"strings"
+)
+
+// If Name == "", the tree is empty.
+type tree struct {
+	name          string
+	siblings      []string
+	descendants   []*tree
+	root          bool
+	hyphaIterator func(func(string))
+}
+
+// TreeAsHtml generates a tree for `hyphaName`. `hyphaStorage` has this type because package `tree` has no access to `HyphaData` data type. One day it shall have it, I guess.
+func TreeAsHtml(hyphaName string, hyphaIterator func(func(string))) string {
+	t := &tree{name: hyphaName, root: true, hyphaIterator: hyphaIterator}
+	t.fill()
+	return t.asHtml()
+}
+
+// subtree adds a descendant tree to `t` and returns that tree.
+func (t *tree) fork(descendantName string) *tree {
+	subt := &tree{
+		name:          descendantName,
+		root:          false,
+		hyphaIterator: t.hyphaIterator,
+	}
+	t.descendants = append(t.descendants, subt)
+	return subt
+}
+
+// Compares names and does something with them, may generate a subtree.
+func (t *tree) compareNamesAndAppend(name2 string) {
+	switch {
+	case t.name == name2:
+	case t.root && path.Dir(t.name) == path.Dir(name2):
+		t.siblings = append(t.siblings, name2)
+	case t.name == path.Dir(name2):
+		t.fork(name2).fill()
+	}
+}
+
+// Fills t.siblings and t.descendants, sorts them and does the same to the descendants.
+func (t *tree) fill() {
+	t.hyphaIterator(func(hyphaName string) {
+		t.compareNamesAndAppend(hyphaName)
+	})
+	sort.Strings(t.siblings)
+	sort.Slice(t.descendants, func(i, j int) bool {
+		return t.descendants[i].name < t.descendants[j].name
+	})
+}
+
+// asHtml returns HTML representation of a tree.
+// It applies itself recursively on the tree's children.
+func (t *tree) asHtml() (html string) {
+	if t.root {
+		for _, siblingName := range t.siblings {
+			html += navitreeEntry(siblingName, "navitree__sibling")
+		}
+		html += navitreeEntry(t.name, "navitree__pagename")
+	} else {
+		html += navitreeEntry(t.name, "navitree__name")
+	}
+
+	for _, subtree := range t.descendants {
+		html += subtree.asHtml()
+	}
+
+	return `<ul class="navitree__node">` + html + `</ul>`
+}
+
+// Strip hypha name from all ancestor names, replace _ with spaces, title case
+func beautifulName(uglyName string) string {
+	return strings.Title(strings.ReplaceAll(path.Base(uglyName), "_", " "))
+}
+
+// navitreeEntry is a small utility function that makes generating html easier.
+func navitreeEntry(name, class string) string {
+	return fmt.Sprintf(`<li class="navitree__entry %s">
+	<a class="navitree__link" href="/page/%s">%s</a>
+</li>
+`, class, name, beautifulName(name))
+}