Folder Sidebar

tree.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"net/http"
 	"os"
+	"path/filepath"
 	"sort"
 	"strings"
 )
@@ -11,6 +12,9 @@ import (
 type treeEntry struct {
 	Name string `json:"name"`
 	Kind string `json:"kind"`
+	// Children is populated only along the expandTo chain (see handleTree);
+	// omitted otherwise so the flat picker listing keeps its original shape.
+	Children []treeEntry `json:"children,omitempty"`
 }
 
 type treeResponse struct {
@@ -42,6 +46,14 @@ func (h *handler) handleTree(w http.ResponseWriter, r *http.Request, urlPath, fs
 		return
 	}
 
+	// expandTo asks for a nested listing: each folder along the ancestor chain
+	// carries its own children, recursively, down to the target. Used by the
+	// tree sidebar to render the current page's chain in one request. The flat
+	// picker omits expandTo and is unaffected.
+	if expandTo := r.URL.Query().Get("expandTo"); expandTo != "" {
+		expandTreeChain(fsPath, entries, treePathSegments(expandTo))
+	}
+
 	resp := treeResponse{Path: canonicalTreePath(urlPath), Entries: entries}
 	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	_ = json.NewEncoder(w).Encode(resp)
@@ -83,3 +95,39 @@ func listTreeEntries(fsPath string) ([]treeEntry, error) {
 	sort.Slice(files, func(i, j int) bool { return files[i].Name < files[j].Name })
 	return append(folders, files...), nil
 }
+
+// treePathSegments splits a wiki path into its non-empty segments.
+func treePathSegments(p string) []string {
+	var segs []string
+	for _, s := range strings.Split(p, "/") {
+		if s != "" {
+			segs = append(segs, s)
+		}
+	}
+	return segs
+}
+
+// expandTreeChain walks segs, matching each against a folder in entries by
+// name, loading that folder's children in place, and recursing. The walk stops
+// at the deepest matching segment, so a stale or deleted path simply expands as
+// far as it still exists. Segments only ever match real directory names from
+// listTreeEntries (no "." or ".." entries), so this cannot traverse outside the
+// listed tree.
+func expandTreeChain(fsPath string, entries []treeEntry, segs []string) {
+	if len(segs) == 0 {
+		return
+	}
+	for i := range entries {
+		if entries[i].Kind != "folder" || entries[i].Name != segs[0] {
+			continue
+		}
+		childFs := filepath.Join(fsPath, segs[0])
+		kids, err := listTreeEntries(childFs)
+		if err != nil {
+			return
+		}
+		entries[i].Children = kids
+		expandTreeChain(childFs, entries[i].Children, segs[1:])
+		return
+	}
+}