Refactor sidebar label selector (#32460)

Introduce `issueSidebarLabelsData` to handle all sidebar labels related data.

22 files changed, 275 insertions, 232 deletions

diff --git a/routers/web/repo/compare.go b/routers/web/repo/compare.go
index 3477ba36e8..9a7d3dfbf6 100644
--- a/routers/web/repo/compare.go
+++ b/routers/web/repo/compare.go
@@ -788,7 +788,11 @@ func CompareDiff(ctx *context.Context) {
 
 		if !nothingToCompare {
 			// Setup information for new form.
-			RetrieveRepoMetas(ctx, ctx.Repo.Repository, true)
+			retrieveRepoMetasForIssueWriter(ctx, ctx.Repo.Repository, true)
+			if ctx.Written() {
+				return
+			}
+			labelsData := retrieveRepoLabels(ctx, ctx.Repo.Repository, 0, true)
 			if ctx.Written() {
 				return
 			}
@@ -796,6 +800,10 @@ func CompareDiff(ctx *context.Context) {
 			if ctx.Written() {
 				return
 			}
+			_, templateErrs := setTemplateIfExists(ctx, pullRequestTemplateKey, pullRequestTemplateCandidates, labelsData)
+			if len(templateErrs) > 0 {
+				ctx.Flash.Warning(renderErrorOfTemplates(ctx, templateErrs), true)
+			}
 		}
 	}
 	beforeCommitID := ctx.Data["BeforeCommitID"].(string)
@@ -808,11 +816,6 @@ func CompareDiff(ctx *context.Context) {
 	ctx.Data["Title"] = "Comparing " + base.ShortSha(beforeCommitID) + separator + base.ShortSha(afterCommitID)
 
 	ctx.Data["IsDiffCompare"] = true
-	_, templateErrs := setTemplateIfExists(ctx, pullRequestTemplateKey, pullRequestTemplateCandidates)
-
-	if len(templateErrs) > 0 {
-		ctx.Flash.Warning(renderErrorOfTemplates(ctx, templateErrs), true)
-	}
 
 	if content, ok := ctx.Data["content"].(string); ok && content != "" {
 		// If a template content is set, prepend the "content". In this case that's only
diff --git a/routers/web/repo/issue.go b/routers/web/repo/issue.go
index 7fa8d428d3..a4e2fd8cea 100644
--- a/routers/web/repo/issue.go
+++ b/routers/web/repo/issue.go
@@ -870,51 +870,112 @@ func RetrieveRepoReviewers(ctx *context.Context, repo *repo_model.Repository, is
 	ctx.Data["IssueSidebarReviewersData"] = data
 }
 
-// RetrieveRepoMetas find all the meta information of a repository
-func RetrieveRepoMetas(ctx *context.Context, repo *repo_model.Repository, isPull bool) []*issues_model.Label {
-	if !ctx.Repo.CanWriteIssuesOrPulls(isPull) {
-		return nil
+type issueSidebarLabelsData struct {
+	Repository       *repo_model.Repository
+	RepoLink         string
+	IssueID          int64
+	IsPullRequest    bool
+	AllLabels        []*issues_model.Label
+	RepoLabels       []*issues_model.Label
+	OrgLabels        []*issues_model.Label
+	SelectedLabelIDs string
+}
+
+func makeSelectedStringIDs[KeyType, ItemType comparable](
+	allLabels []*issues_model.Label, candidateKey func(candidate *issues_model.Label) KeyType,
+	selectedItems []ItemType, selectedKey func(selected ItemType) KeyType,
+) string {
+	selectedIDSet := make(container.Set[string])
+	allLabelMap := map[KeyType]*issues_model.Label{}
+	for _, label := range allLabels {
+		allLabelMap[candidateKey(label)] = label
+	}
+	for _, item := range selectedItems {
+		if label, ok := allLabelMap[selectedKey(item)]; ok {
+			label.IsChecked = true
+			selectedIDSet.Add(strconv.FormatInt(label.ID, 10))
+		}
+	}
+	ids := selectedIDSet.Values()
+	sort.Strings(ids)
+	return strings.Join(ids, ",")
+}
+
+func (d *issueSidebarLabelsData) SetSelectedLabels(labels []*issues_model.Label) {
+	d.SelectedLabelIDs = makeSelectedStringIDs(
+		d.AllLabels, func(label *issues_model.Label) int64 { return label.ID },
+		labels, func(label *issues_model.Label) int64 { return label.ID },
+	)
+}
+
+func (d *issueSidebarLabelsData) SetSelectedLabelNames(labelNames []string) {
+	d.SelectedLabelIDs = makeSelectedStringIDs(
+		d.AllLabels, func(label *issues_model.Label) string { return strings.ToLower(label.Name) },
+		labelNames, strings.ToLower,
+	)
+}
+
+func (d *issueSidebarLabelsData) SetSelectedLabelIDs(labelIDs []int64) {
+	d.SelectedLabelIDs = makeSelectedStringIDs(
+		d.AllLabels, func(label *issues_model.Label) int64 { return label.ID },
+		labelIDs, func(labelID int64) int64 { return labelID },
+	)
+}
+
+func retrieveRepoLabels(ctx *context.Context, repo *repo_model.Repository, issueID int64, isPull bool) *issueSidebarLabelsData {
+	labelsData := &issueSidebarLabelsData{
+		Repository:    repo,
+		RepoLink:      ctx.Repo.RepoLink,
+		IssueID:       issueID,
+		IsPullRequest: isPull,
 	}
+	ctx.Data["IssueSidebarLabelsData"] = labelsData
 
 	labels, err := issues_model.GetLabelsByRepoID(ctx, repo.ID, "", db.ListOptions{})
 	if err != nil {
 		ctx.ServerError("GetLabelsByRepoID", err)
 		return nil
 	}
-	ctx.Data["Labels"] = labels
+	labelsData.RepoLabels = labels
+
 	if repo.Owner.IsOrganization() {
 		orgLabels, err := issues_model.GetLabelsByOrgID(ctx, repo.Owner.ID, ctx.FormString("sort"), db.ListOptions{})
 		if err != nil {
 			return nil
 		}
+		labelsData.OrgLabels = orgLabels
+	}
+	labelsData.AllLabels = append(labelsData.AllLabels, labelsData.RepoLabels...)
+	labelsData.AllLabels = append(labelsData.AllLabels, labelsData.OrgLabels...)
+	return labelsData
+}
 
-		ctx.Data["OrgLabels"] = orgLabels
-		labels = append(labels, orgLabels...)
+// retrieveRepoMetasForIssueWriter finds some the meta information of a repository for an issue/pr writer
+func retrieveRepoMetasForIssueWriter(ctx *context.Context, repo *repo_model.Repository, isPull bool) {
+	if !ctx.Repo.CanWriteIssuesOrPulls(isPull) {
+		return
 	}
 
 	RetrieveRepoMilestonesAndAssignees(ctx, repo)
 	if ctx.Written() {
-		return nil
+		return
 	}
 
 	retrieveProjects(ctx, repo)
 	if ctx.Written() {
-		return nil
+		return
 	}
 
 	PrepareBranchList(ctx)
 	if ctx.Written() {
-		return nil
+		return
 	}
-
 	// Contains true if the user can create issue dependencies
 	ctx.Data["CanCreateIssueDependencies"] = ctx.Repo.CanCreateIssueDependencies(ctx, ctx.Doer, isPull)
-
-	return labels
 }
 
 // Tries to load and set an issue template. The first return value indicates if a template was loaded.
-func setTemplateIfExists(ctx *context.Context, ctxDataKey string, possibleFiles []string) (bool, map[string]error) {
+func setTemplateIfExists(ctx *context.Context, ctxDataKey string, possibleFiles []string, labelsData *issueSidebarLabelsData) (bool, map[string]error) {
 	commit, err := ctx.Repo.GitRepo.GetBranchCommit(ctx.Repo.Repository.DefaultBranch)
 	if err != nil {
 		return false, nil
@@ -951,26 +1012,9 @@ func setTemplateIfExists(ctx *context.Context, ctxDataKey string, possibleFiles
 			ctx.Data["Fields"] = template.Fields
 			ctx.Data["TemplateFile"] = template.FileName
 		}
-		labelIDs := make([]string, 0, len(template.Labels))
-		if repoLabels, err := issues_model.GetLabelsByRepoID(ctx, ctx.Repo.Repository.ID, "", db.ListOptions{}); err == nil {
-			ctx.Data["Labels"] = repoLabels
-			if ctx.Repo.Owner.IsOrganization() {
-				if orgLabels, err := issues_model.GetLabelsByOrgID(ctx, ctx.Repo.Owner.ID, ctx.FormString("sort"), db.ListOptions{}); err == nil {
-					ctx.Data["OrgLabels"] = orgLabels
-					repoLabels = append(repoLabels, orgLabels...)
-				}
-			}
 
-			for _, metaLabel := range template.Labels {
-				for _, repoLabel := range repoLabels {
-					if strings.EqualFold(repoLabel.Name, metaLabel) {
-						repoLabel.IsChecked = true
-						labelIDs = append(labelIDs, strconv.FormatInt(repoLabel.ID, 10))
-						break
-					}
-				}
-			}
-		}
+		labelsData.SetSelectedLabelNames(template.Labels)
+
 		selectedAssigneeIDs := make([]int64, 0, len(template.Assignees))
 		selectedAssigneeIDStrings := make([]string, 0, len(template.Assignees))
 		if userIDs, err := user_model.GetUserIDsByNames(ctx, template.Assignees, false); err == nil {
@@ -983,8 +1027,7 @@ func setTemplateIfExists(ctx *context.Context, ctxDataKey string, possibleFiles
 		if template.Ref != "" && !strings.HasPrefix(template.Ref, "refs/") { // Assume that the ref intended is always a branch - for tags users should use refs/tags/<ref>
 			template.Ref = git.BranchPrefix + template.Ref
 		}
-		ctx.Data["HasSelectedLabel"] = len(labelIDs) > 0
-		ctx.Data["label_ids"] = strings.Join(labelIDs, ",")
+
 		ctx.Data["HasSelectedAssignee"] = len(selectedAssigneeIDs) > 0
 		ctx.Data["assignee_ids"] = strings.Join(selectedAssigneeIDStrings, ",")
 		ctx.Data["SelectedAssigneeIDs"] = selectedAssigneeIDs
@@ -1042,8 +1085,14 @@ func NewIssue(ctx *context.Context) {
 		}
 	}
 
-	RetrieveRepoMetas(ctx, ctx.Repo.Repository, false)
-
+	retrieveRepoMetasForIssueWriter(ctx, ctx.Repo.Repository, false)
+	if ctx.Written() {
+		return
+	}
+	labelsData := retrieveRepoLabels(ctx, ctx.Repo.Repository, 0, false)
+	if ctx.Written() {
+		return
+	}
 	tags, err := repo_model.GetTagNamesByRepoID(ctx, ctx.Repo.Repository.ID)
 	if err != nil {
 		ctx.ServerError("GetTagNamesByRepoID", err)
@@ -1052,7 +1101,7 @@ func NewIssue(ctx *context.Context) {
 	ctx.Data["Tags"] = tags
 
 	ret := issue_service.ParseTemplatesFromDefaultBranch(ctx.Repo.Repository, ctx.Repo.GitRepo)
-	templateLoaded, errs := setTemplateIfExists(ctx, issueTemplateKey, IssueTemplateCandidates)
+	templateLoaded, errs := setTemplateIfExists(ctx, issueTemplateKey, IssueTemplateCandidates, labelsData)
 	for k, v := range errs {
 		ret.TemplateErrors[k] = v
 	}
@@ -1161,34 +1210,25 @@ func ValidateRepoMetas(ctx *context.Context, form forms.CreateIssueForm, isPull
 		err  error
 	)
 
-	labels := RetrieveRepoMetas(ctx, ctx.Repo.Repository, isPull)
+	retrieveRepoMetasForIssueWriter(ctx, ctx.Repo.Repository, isPull)
+	if ctx.Written() {
+		return ret
+	}
+	labelsData := retrieveRepoLabels(ctx, ctx.Repo.Repository, 0, isPull)
 	if ctx.Written() {
 		return ret
 	}
 
 	var labelIDs []int64
-	hasSelected := false
 	// Check labels.
 	if len(form.LabelIDs) > 0 {
 		labelIDs, err = base.StringsToInt64s(strings.Split(form.LabelIDs, ","))
 		if err != nil {
 			return ret
 		}
-		labelIDMark := make(container.Set[int64])
-		labelIDMark.AddMultiple(labelIDs...)
-
-		for i := range labels {
-			if labelIDMark.Contains(labels[i].ID) {
-				labels[i].IsChecked = true
-				hasSelected = true
-			}
-		}
+		labelsData.SetSelectedLabelIDs(labelIDs)
 	}
 
-	ctx.Data["Labels"] = labels
-	ctx.Data["HasSelectedLabel"] = hasSelected
-	ctx.Data["label_ids"] = form.LabelIDs
-
 	// Check milestone.
 	milestoneID := form.MilestoneID
 	if milestoneID > 0 {
@@ -1579,38 +1619,15 @@ func ViewIssue(ctx *context.Context) {
 		}
 	}
 
-	// Metas.
-	// Check labels.
-	labelIDMark := make(container.Set[int64])
-	for _, label := range issue.Labels {
-		labelIDMark.Add(label.ID)
-	}
-	labels, err := issues_model.GetLabelsByRepoID(ctx, repo.ID, "", db.ListOptions{})
-	if err != nil {
-		ctx.ServerError("GetLabelsByRepoID", err)
+	retrieveRepoMetasForIssueWriter(ctx, repo, issue.IsPull)
+	if ctx.Written() {
 		return
 	}
-	ctx.Data["Labels"] = labels
-
-	if repo.Owner.IsOrganization() {
-		orgLabels, err := issues_model.GetLabelsByOrgID(ctx, repo.Owner.ID, ctx.FormString("sort"), db.ListOptions{})
-		if err != nil {
-			ctx.ServerError("GetLabelsByOrgID", err)
-			return
-		}
-		ctx.Data["OrgLabels"] = orgLabels
-
-		labels = append(labels, orgLabels...)
-	}
-
-	hasSelected := false
-	for i := range labels {
-		if labelIDMark.Contains(labels[i].ID) {
-			labels[i].IsChecked = true
-			hasSelected = true
-		}
+	labelsData := retrieveRepoLabels(ctx, repo, issue.ID, issue.IsPull)
+	if ctx.Written() {
+		return
 	}
-	ctx.Data["HasSelectedLabel"] = hasSelected
+	labelsData.SetSelectedLabels(issue.Labels)
 
 	// Check milestone and assignee.
 	if ctx.Repo.CanWriteIssuesOrPulls(issue.IsPull) {
diff --git a/routers/web/repo/issue_label.go b/routers/web/repo/issue_label.go
index 81bee4dbb5..4874baaa54 100644
--- a/routers/web/repo/issue_label.go
+++ b/routers/web/repo/issue_label.go
@@ -53,11 +53,11 @@ func InitializeLabels(ctx *context.Context) {
 	ctx.Redirect(ctx.Repo.RepoLink + "/labels")
 }
 
-// RetrieveLabels find all the labels of a repository and organization
-func RetrieveLabels(ctx *context.Context) {
+// RetrieveLabelsForList find all the labels of a repository and organization, it is only used by "/labels" page to list all labels
+func RetrieveLabelsForList(ctx *context.Context) {
 	labels, err := issues_model.GetLabelsByRepoID(ctx, ctx.Repo.Repository.ID, ctx.FormString("sort"), db.ListOptions{})
 	if err != nil {
-		ctx.ServerError("RetrieveLabels.GetLabels", err)
+		ctx.ServerError("RetrieveLabelsForList.GetLabels", err)
 		return
 	}
 
diff --git a/routers/web/repo/issue_label_test.go b/routers/web/repo/issue_label_test.go
index 93fc72300b..c86a03da51 100644
--- a/routers/web/repo/issue_label_test.go
+++ b/routers/web/repo/issue_label_test.go
@@ -62,7 +62,7 @@ func TestRetrieveLabels(t *testing.T) {
 		contexttest.LoadUser(t, ctx, 2)
 		contexttest.LoadRepo(t, ctx, testCase.RepoID)
 		ctx.Req.Form.Set("sort", testCase.Sort)
-		RetrieveLabels(ctx)
+		RetrieveLabelsForList(ctx)
 		assert.False(t, ctx.Written())
 		labels, ok := ctx.Data["Labels"].([]*issues_model.Label)
 		assert.True(t, ok)
diff --git a/routers/web/web.go b/routers/web/web.go
index 29dd8a8edc..907bf88f6f 100644
--- a/routers/web/web.go
+++ b/routers/web/web.go
@@ -1163,7 +1163,7 @@ func registerRoutes(m *web.Router) {
 		m.Get("/issues/posters", repo.IssuePosters) // it can't use {type:issues|pulls} because it would conflict with other routes like "/pulls/{index}"
 		m.Get("/pulls/posters", repo.PullPosters)
 		m.Get("/comments/{id}/attachments", repo.GetCommentAttachments)
-		m.Get("/labels", repo.RetrieveLabels, repo.Labels)
+		m.Get("/labels", repo.RetrieveLabelsForList, repo.Labels)
 		m.Get("/milestones", repo.Milestones)
 		m.Get("/milestone/{id}", context.RepoRef(), repo.MilestoneIssuesAndPulls)
 		m.Group("/{type:issues|pulls}", func() {
diff --git a/templates/repo/issue/labels/label.tmpl b/templates/repo/issue/labels/label.tmpl
deleted file mode 100644
index f40c792da7..0000000000
--- a/templates/repo/issue/labels/label.tmpl
+++ /dev/null
@@ -1,7 +0,0 @@
-<a
-	class="item {{if not .label.IsChecked}}tw-hidden{{end}}"
-	id="label_{{.label.ID}}"
-	href="{{.root.RepoLink}}/{{if or .root.IsPull .root.Issue.IsPull}}pulls{{else}}issues{{end}}?labels={{.label.ID}}"{{/* FIXME: use .root.Issue.Link or create .root.Link */}}
->
-	{{- ctx.RenderUtils.RenderLabel .label -}}
-</a>
diff --git a/templates/repo/issue/labels/labels_selector_field.tmpl b/templates/repo/issue/labels/labels_selector_field.tmpl
deleted file mode 100644
index 96fb658664..0000000000
--- a/templates/repo/issue/labels/labels_selector_field.tmpl
+++ /dev/null
@@ -1,46 +0,0 @@
-<div class="ui {{if or (not .HasIssuesOrPullsWritePermission) .Repository.IsArchived}}disabled{{end}} floating jump select-label dropdown">
-	<span class="text muted flex-text-block">
-		<strong>{{ctx.Locale.Tr "repo.issues.new.labels"}}</strong>
-		{{if and .HasIssuesOrPullsWritePermission (not .Repository.IsArchived)}}
-			{{svg "octicon-gear" 16 "tw-ml-1"}}
-		{{end}}
-	</span>
-	<div class="filter menu" {{if .Issue}}data-action="update" data-issue-id="{{$.Issue.ID}}" data-update-url="{{$.RepoLink}}/issues/labels"{{else}}data-id="#label_ids"{{end}}>
-		{{if or .Labels .OrgLabels}}
-			<div class="ui icon search input">
-				<i class="icon">{{svg "octicon-search" 16}}</i>
-				<input type="text" placeholder="{{ctx.Locale.Tr "repo.issues.filter_labels"}}">
-			</div>
-		{{end}}
-		<a class="no-select item" href="#">{{ctx.Locale.Tr "repo.issues.new.clear_labels"}}</a>
-		{{if or .Labels .OrgLabels}}
-			{{$previousExclusiveScope := "_no_scope"}}
-			{{range .Labels}}
-				{{$exclusiveScope := .ExclusiveScope}}
-				{{if and (ne $previousExclusiveScope "_no_scope") (ne $previousExclusiveScope $exclusiveScope)}}
-					<div class="divider"></div>
-				{{end}}
-				{{$previousExclusiveScope = $exclusiveScope}}
-				<a class="{{if .IsChecked}}checked{{end}} item" href="#" data-id="{{.ID}}" {{if .IsArchived}}data-is-archived{{end}} data-id-selector="#label_{{.ID}}" data-scope="{{$exclusiveScope}}"><span class="octicon-check {{if not .IsChecked}}tw-invisible{{end}}">{{svg (Iif $exclusiveScope "octicon-dot-fill" "octicon-check")}}</span>&nbsp;&nbsp;{{ctx.RenderUtils.RenderLabel .}}
-					{{if .Description}}<br><small class="desc">{{.Description | ctx.RenderUtils.RenderEmoji}}</small>{{end}}
-					<p class="archived-label-hint">{{template "repo/issue/labels/label_archived" .}}</p>
-				</a>
-			{{end}}
-			<div class="divider"></div>
-			{{$previousExclusiveScope = "_no_scope"}}
-			{{range .OrgLabels}}
-				{{$exclusiveScope := .ExclusiveScope}}
-				{{if and (ne $previousExclusiveScope "_no_scope") (ne $previousExclusiveScope $exclusiveScope)}}
-					<div class="divider"></div>
-				{{end}}
-				{{$previousExclusiveScope = $exclusiveScope}}
-				<a class="{{if .IsChecked}}checked{{end}} item" href="#" data-id="{{.ID}}" {{if .IsArchived}}data-is-archived{{end}} data-id-selector="#label_{{.ID}}" data-scope="{{$exclusiveScope}}"><span class="octicon-check {{if not .IsChecked}}tw-invisible{{end}}">{{svg (Iif $exclusiveScope "octicon-dot-fill" "octicon-check")}}</span>&nbsp;&nbsp;{{ctx.RenderUtils.RenderLabel .}}
-					{{if .Description}}<br><small class="desc">{{.Description | ctx.RenderUtils.RenderEmoji}}</small>{{end}}
-					<p class="archived-label-hint">{{template "repo/issue/labels/label_archived" .}}</p>
-				</a>
-			{{end}}
-		{{else}}
-			<div class="disabled item">{{ctx.Locale.Tr "repo.issues.new.no_items"}}</div>
-		{{end}}
-	</div>
-</div>
diff --git a/templates/repo/issue/labels/labels_sidebar.tmpl b/templates/repo/issue/labels/labels_sidebar.tmpl
deleted file mode 100644
index 0b7b9b8969..0000000000
--- a/templates/repo/issue/labels/labels_sidebar.tmpl
+++ /dev/null
@@ -1,11 +0,0 @@
-<div class="ui labels list">
-	<span class="labels-list">
-		<span class="no-select {{if .root.HasSelectedLabel}}tw-hidden{{end}}">{{ctx.Locale.Tr "repo.issues.new.no_label"}}</span>
-		{{range .root.Labels}}
-			{{template "repo/issue/labels/label" dict "root" $.root "label" .}}
-		{{end}}
-		{{range .root.OrgLabels}}
-			{{template "repo/issue/labels/label" dict "root" $.root "label" .}}
-		{{end}}
-	</span>
-</div>
diff --git a/templates/repo/issue/new_form.tmpl b/templates/repo/issue/new_form.tmpl
index 190d52cf47..65d359e9dc 100644
--- a/templates/repo/issue/new_form.tmpl
+++ b/templates/repo/issue/new_form.tmpl
@@ -18,15 +18,15 @@
 						<input type="hidden" name="template-file" value="{{.TemplateFile}}">
 						{{range .Fields}}
 							{{if eq .Type "input"}}
-								{{template "repo/issue/fields/input" "item" .}}
+								{{template "repo/issue/fields/input" dict "item" .}}
 							{{else if eq .Type "markdown"}}
-								{{template "repo/issue/fields/markdown" "item" .}}
+								{{template "repo/issue/fields/markdown" dict "item" .}}
 							{{else if eq .Type "textarea"}}
-								{{template "repo/issue/fields/textarea" "item" . "root" $}}
+								{{template "repo/issue/fields/textarea" dict "item" . "root" $}}
 							{{else if eq .Type "dropdown"}}
-								{{template "repo/issue/fields/dropdown" "item" .}}
+								{{template "repo/issue/fields/dropdown" dict "item" .}}
 							{{else if eq .Type "checkboxes"}}
-								{{template "repo/issue/fields/checkboxes" "item" .}}
+								{{template "repo/issue/fields/checkboxes" dict "item" .}}
 							{{end}}
 						{{end}}
 					{{else}}
@@ -49,13 +49,11 @@
 	<div class="issue-content-right ui segment">
 		{{template "repo/issue/branch_selector_field" $}}
 		{{if .PageIsComparePull}}
-			{{template "repo/issue/sidebar/reviewer_list" dict "IssueSidebarReviewersData" $.IssueSidebarReviewersData}}
+			{{template "repo/issue/sidebar/reviewer_list" $.IssueSidebarReviewersData}}
 			<div class="divider"></div>
 		{{end}}
 
-		<input id="label_ids" name="label_ids" type="hidden" value="{{.label_ids}}">
-		{{template "repo/issue/labels/labels_selector_field" .}}
-		{{template "repo/issue/labels/labels_sidebar" dict "root" $}}
+		{{template "repo/issue/sidebar/label_list" $.IssueSidebarLabelsData}}
 
 		<div class="divider"></div>
 
diff --git a/templates/repo/issue/sidebar/label_list.tmpl b/templates/repo/issue/sidebar/label_list.tmpl
new file mode 100644
index 0000000000..e9f4baa433
--- /dev/null
+++ b/templates/repo/issue/sidebar/label_list.tmpl
@@ -0,0 +1,51 @@
+{{$data := .}}
+{{$canChange := and ctx.RootData.HasIssuesOrPullsWritePermission (not $data.Repository.IsArchived)}}
+<div class="issue-sidebar-combo" {{if $data.IssueID}}data-update-url="{{$data.RepoLink}}/issues/labels?issue_ids={{$data.IssueID}}"{{end}}>
+	<input class="combo-value" name="label_ids" type="hidden" value="{{$data.SelectedLabelIDs}}">
+	<div class="ui dropdown {{if not $canChange}}disabled{{end}}">
+		<a class="text muted">
+			<strong>{{ctx.Locale.Tr "repo.issues.new.labels"}}</strong> {{if $canChange}}{{svg "octicon-gear"}}{{end}}
+		</a>
+		<div class="menu">
+			{{if not $data.AllLabels}}
+				<div class="item disabled">{{ctx.Locale.Tr "repo.issues.new.no_items"}}</div>
+			{{else}}
+				<div class="ui icon search input">
+					<i class="icon">{{svg "octicon-search" 16}}</i>
+					<input type="text" placeholder="{{ctx.Locale.Tr "repo.issues.filter_labels"}}">
+				</div>
+				<a class="item clear-selection" href="#">{{ctx.Locale.Tr "repo.issues.new.clear_labels"}}</a>
+				{{$previousExclusiveScope := "_no_scope"}}
+				{{range .RepoLabels}}
+					{{$exclusiveScope := .ExclusiveScope}}
+					{{if and (ne $previousExclusiveScope "_no_scope") (ne $previousExclusiveScope $exclusiveScope)}}
+						<div class="divider"></div>
+					{{end}}
+					{{$previousExclusiveScope = $exclusiveScope}}
+					{{template "repo/issue/sidebar/label_list_item" dict "Label" .}}
+				{{end}}
+				<div class="divider"></div>
+				{{$previousExclusiveScope = "_no_scope"}}
+				{{range .OrgLabels}}
+					{{$exclusiveScope := .ExclusiveScope}}
+					{{if and (ne $previousExclusiveScope "_no_scope") (ne $previousExclusiveScope $exclusiveScope)}}
+						<div class="divider"></div>
+					{{end}}
+					{{$previousExclusiveScope = $exclusiveScope}}
+					{{template "repo/issue/sidebar/label_list_item" dict "Label" .}}
+				{{end}}
+			{{end}}
+		</div>
+	</div>
+
+	<div class="ui list labels-list tw-my-2 tw-flex tw-gap-2">
+		<span class="item empty-list {{if $data.SelectedLabelIDs}}tw-hidden{{end}}">{{ctx.Locale.Tr "repo.issues.new.no_label"}}</span>
+		{{range $data.AllLabels}}
+			{{if .IsChecked}}
+				<a class="item" href="{{$data.RepoLink}}/{{if $data.IsPullRequest}}pulls{{else}}issues{{end}}?labels={{.ID}}">
+					{{- ctx.RenderUtils.RenderLabel . -}}
+				</a>
+			{{end}}
+		{{end}}
+	</div>
+</div>
diff --git a/templates/repo/issue/sidebar/label_list_item.tmpl b/templates/repo/issue/sidebar/label_list_item.tmpl
new file mode 100644
index 0000000000..ad878e918b
--- /dev/null
+++ b/templates/repo/issue/sidebar/label_list_item.tmpl
@@ -0,0 +1,11 @@
+{{$label := .Label}}
+<a class="item {{if $label.IsChecked}}checked{{else if $label.IsArchived}}tw-hidden{{end}}" href="#"
+	data-scope="{{$label.ExclusiveScope}}" data-value="{{$label.ID}}" {{if $label.IsArchived}}data-is-archived{{end}}
+>
+	<span class="item-check-mark">{{svg (Iif $label.ExclusiveScope "octicon-dot-fill" "octicon-check")}}</span>
+	{{ctx.RenderUtils.RenderLabel $label}}
+	<div class="item-secondary-info">
+		{{if $label.Description}}<div class="tw-pl-[20px]"><small>{{$label.Description | ctx.RenderUtils.RenderEmoji}}</small></div>{{end}}
+		<div class="archived-label-hint">{{template "repo/issue/labels/label_archived" $label}}</div>
+	</div>
+</a>
diff --git a/templates/repo/issue/sidebar/reviewer_list.tmpl b/templates/repo/issue/sidebar/reviewer_list.tmpl
index 2d3218e927..cf7b97c02b 100644
--- a/templates/repo/issue/sidebar/reviewer_list.tmpl
+++ b/templates/repo/issue/sidebar/reviewer_list.tmpl
@@ -1,11 +1,9 @@
-{{$data := .IssueSidebarReviewersData}}
+{{$data := .}}
 {{$hasCandidates := or $data.Reviewers $data.TeamReviewers}}
-<div class="issue-sidebar-combo" data-sidebar-combo-for="reviewers"
-		{{if $data.IssueID}}data-update-url="{{$data.RepoLink}}/issues/request_review?issue_ids={{$data.IssueID}}"{{end}}
->
+<div class="issue-sidebar-combo" {{if $data.IssueID}}data-update-url="{{$data.RepoLink}}/issues/request_review?issue_ids={{$data.IssueID}}"{{end}}>
 	<input type="hidden" class="combo-value" name="reviewer_ids">{{/* match CreateIssueForm */}}
-	<div class="ui dropdown custom {{if or (not $hasCandidates) (not $data.CanChooseReviewer)}}disabled{{end}}">
-		<a class="muted text">
+	<div class="ui dropdown {{if or (not $hasCandidates) (not $data.CanChooseReviewer)}}disabled{{end}}">
+		<a class="text muted">
 			<strong>{{ctx.Locale.Tr "repo.issues.review.reviewers"}}</strong> {{if and $data.CanChooseReviewer}}{{svg "octicon-gear"}}{{end}}
 		</a>
 		<div class="menu flex-items-menu">
@@ -19,7 +17,8 @@
 				{{if .User}}
 					<a class="item muted {{if .Requested}}checked{{end}}" href="{{.User.HomeLink}}" data-value="{{.ItemID}}" data-can-change="{{.CanChange}}"
 						{{if not .CanChange}}data-tooltip-content="{{ctx.Locale.Tr "repo.issues.remove_request_review_block"}}"{{end}}>
-						{{svg "octicon-check"}} {{ctx.AvatarUtils.Avatar .User 20}} {{template "repo/search_name" .User}}
+						<span class="item-check-mark">{{svg "octicon-check"}}</span>
+						{{ctx.AvatarUtils.Avatar .User 20}} {{template "repo/search_name" .User}}
 					</a>
 				{{end}}
 			{{end}}
@@ -29,7 +28,8 @@
 					{{if .Team}}
 						<a class="item muted {{if .Requested}}checked{{end}}" href="#" data-value="{{.ItemID}}" data-can-change="{{.CanChange}}"
 							{{if not .CanChange}} data-tooltip-content="{{ctx.Locale.Tr "repo.issues.remove_request_review_block"}}"{{end}}>
-							{{svg "octicon-check"}} {{svg "octicon-people" 20}} {{$data.RepoOwnerName}}/{{.Team.Name}}
+							<span class="item-check-mark">{{svg "octicon-check"}}</span>
+							{{svg "octicon-people" 20}} {{$data.RepoOwnerName}}/{{.Team.Name}}
 						</a>
 					{{end}}
 				{{end}}
diff --git a/templates/repo/issue/view_content/sidebar.tmpl b/templates/repo/issue/view_content/sidebar.tmpl
index 7a40274759..0fae1e9e1c 100644
--- a/templates/repo/issue/view_content/sidebar.tmpl
+++ b/templates/repo/issue/view_content/sidebar.tmpl
@@ -2,13 +2,12 @@
 	{{template "repo/issue/branch_selector_field" $}}
 
 	{{if .Issue.IsPull}}
-		{{template "repo/issue/sidebar/reviewer_list" dict "IssueSidebarReviewersData" $.IssueSidebarReviewersData}}
+		{{template "repo/issue/sidebar/reviewer_list" $.IssueSidebarReviewersData}}
 		{{template "repo/issue/sidebar/wip_switch" $}}
 		<div class="divider"></div>
 	{{end}}
 
-	{{template "repo/issue/labels/labels_selector_field" $}}
-	{{template "repo/issue/labels/labels_sidebar" dict "root" $}}
+	{{template "repo/issue/sidebar/label_list" $.IssueSidebarLabelsData}}
 
 	{{template "repo/issue/sidebar/milestone_list" $}}
 	{{template "repo/issue/sidebar/project_list" $}}
diff --git a/web_src/css/repo.css b/web_src/css/repo.css
index 185a5f6f55..ff8342d29a 100644
--- a/web_src/css/repo.css
+++ b/web_src/css/repo.css
@@ -50,7 +50,7 @@
   width: 300px;
 }
 
-.issue-sidebar-combo .ui.dropdown .item:not(.checked) svg.octicon-check {
+.issue-sidebar-combo .ui.dropdown .item:not(.checked) .item-check-mark {
   visibility: hidden;
 }
 /* ideally, we should move these styles to ".ui.dropdown .menu.flex-items-menu > .item ...", could be done later */
@@ -62,6 +62,8 @@
 .issue-content-right .dropdown > .menu {
   max-width: 270px;
   min-width: 0;
+  max-height: 500px;
+  overflow-x: auto;
 }
 
 @media (max-width: 767.98px) {
@@ -110,10 +112,6 @@
   left: 0;
 }
 
-.repository .select-label .desc {
-  padding-left: 23px;
-}
-
 /* For the secondary pointing menu, respect its own border-bottom */
 /* style reference: https://semantic-ui.com/collections/menu.html#pointing */
 .repository .ui.tabs.container .ui.menu:not(.secondary.pointing) {
diff --git a/web_src/css/repo/issue-label.css b/web_src/css/repo/issue-label.css
index 9b4b144a00..0a25d31da9 100644
--- a/web_src/css/repo/issue-label.css
+++ b/web_src/css/repo/issue-label.css
@@ -47,6 +47,7 @@
 }
 
 .archived-label-hint {
-  float: right;
-  margin: -12px;
+  position: absolute;
+  top: 10px;
+  right: 5px;
 }
diff --git a/web_src/js/features/common-page.ts b/web_src/js/features/common-page.ts
index beec92d152..56c5915b6d 100644
--- a/web_src/js/features/common-page.ts
+++ b/web_src/js/features/common-page.ts
@@ -32,13 +32,13 @@ export function initGlobalDropdown() {
   const $uiDropdowns = fomanticQuery('.ui.dropdown');
 
   // do not init "custom" dropdowns, "custom" dropdowns are managed by their own code.
-  $uiDropdowns.filter(':not(.custom)').dropdown();
+  $uiDropdowns.filter(':not(.custom)').dropdown({hideDividers: 'empty'});
 
   // The "jump" means this dropdown is mainly used for "menu" purpose,
   // clicking an item will jump to somewhere else or trigger an action/function.
   // When a dropdown is used for non-refresh actions with tippy,
   // it must have this "jump" class to hide the tippy when dropdown is closed.
-  $uiDropdowns.filter('.jump').dropdown({
+  $uiDropdowns.filter('.jump').dropdown('setting', {
     action: 'hide',
     onShow() {
       // hide associated tooltip while dropdown is open
diff --git a/web_src/js/features/repo-issue-sidebar-combolist.ts b/web_src/js/features/repo-issue-sidebar-combolist.ts
index d541615988..f408eb43ba 100644
--- a/web_src/js/features/repo-issue-sidebar-combolist.ts
+++ b/web_src/js/features/repo-issue-sidebar-combolist.ts
@@ -1,6 +1,6 @@
 import {fomanticQuery} from '../modules/fomantic/base.ts';
 import {POST} from '../modules/fetch.ts';
-import {queryElemChildren, toggleElem} from '../utils/dom.ts';
+import {queryElemChildren, queryElems, toggleElem} from '../utils/dom.ts';
 
 // if there are draft comments, confirm before reloading, to avoid losing comments
 export function issueSidebarReloadConfirmDraftComment() {
@@ -27,20 +27,37 @@ function collectCheckedValues(elDropdown: HTMLElement) {
 }
 
 export function initIssueSidebarComboList(container: HTMLElement) {
-  if (!container) return;
-
   const updateUrl = container.getAttribute('data-update-url');
   const elDropdown = container.querySelector<HTMLElement>(':scope > .ui.dropdown');
   const elList = container.querySelector<HTMLElement>(':scope > .ui.list');
   const elComboValue = container.querySelector<HTMLInputElement>(':scope > .combo-value');
-  const initialValues = collectCheckedValues(elDropdown);
+  let initialValues = collectCheckedValues(elDropdown);
 
   elDropdown.addEventListener('click', (e) => {
     const elItem = (e.target as HTMLElement).closest('.item');
     if (!elItem) return;
     e.preventDefault();
-    if (elItem.getAttribute('data-can-change') !== 'true') return;
-    elItem.classList.toggle('checked');
+    if (elItem.hasAttribute('data-can-change') && elItem.getAttribute('data-can-change') !== 'true') return;
+
+    if (elItem.matches('.clear-selection')) {
+      queryElems(elDropdown, '.menu > .item', (el) => el.classList.remove('checked'));
+      elComboValue.value = '';
+      return;
+    }
+
+    const scope = elItem.getAttribute('data-scope');
+    if (scope) {
+      // scoped items could only be checked one at a time
+      const elSelected = elDropdown.querySelector<HTMLElement>(`.menu > .item.checked[data-scope="${CSS.escape(scope)}"]`);
+      if (elSelected === elItem) {
+        elItem.classList.toggle('checked');
+      } else {
+        queryElems(elDropdown, `.menu > .item[data-scope="${CSS.escape(scope)}"]`, (el) => el.classList.remove('checked'));
+        elItem.classList.toggle('checked', true);
+      }
+    } else {
+      elItem.classList.toggle('checked');
+    }
     elComboValue.value = collectCheckedValues(elDropdown).join(',');
   });
 
@@ -61,29 +78,28 @@ export function initIssueSidebarComboList(container: HTMLElement) {
     if (changed) issueSidebarReloadConfirmDraftComment();
   };
 
-  const syncList = (changedValues) => {
+  const syncUiList = (changedValues) => {
     const elEmptyTip = elList.querySelector('.item.empty-list');
     queryElemChildren(elList, '.item:not(.empty-list)', (el) => el.remove());
     for (const value of changedValues) {
-      const el = elDropdown.querySelector<HTMLElement>(`.menu > .item[data-value="${value}"]`);
+      const el = elDropdown.querySelector<HTMLElement>(`.menu > .item[data-value="${CSS.escape(value)}"]`);
       const listItem = el.cloneNode(true) as HTMLElement;
-      listItem.querySelector('svg.octicon-check')?.remove();
+      queryElems(listItem, '.item-check-mark, .item-secondary-info', (el) => el.remove());
       elList.append(listItem);
     }
     const hasItems = Boolean(elList.querySelector('.item:not(.empty-list)'));
     toggleElem(elEmptyTip, !hasItems);
   };
 
-  fomanticQuery(elDropdown).dropdown({
+  fomanticQuery(elDropdown).dropdown('setting', {
     action: 'nothing', // do not hide the menu if user presses Enter
     fullTextSearch: 'exact',
     async onHide() {
+      // TODO: support "Esc" to cancel the selection. Use partial page loading to avoid losing inputs.
       const changedValues = collectCheckedValues(elDropdown);
-      if (updateUrl) {
-        await updateToBackend(changedValues); // send requests to backend and reload the page
-      } else {
-        syncList(changedValues); // only update the list in the sidebar
-      }
+      syncUiList(changedValues);
+      if (updateUrl) await updateToBackend(changedValues);
+      initialValues = changedValues;
     },
   });
 }
diff --git a/web_src/js/features/repo-issue-sidebar.md b/web_src/js/features/repo-issue-sidebar.md
new file mode 100644
index 0000000000..3022b52d05
--- /dev/null
+++ b/web_src/js/features/repo-issue-sidebar.md
@@ -0,0 +1,27 @@
+A sidebar combo (dropdown+list) is like this:
+
+```html
+<div class="issue-sidebar-combo" data-update-url="...">
+  <input class="combo-value" name="..." type="hidden" value="...">
+  <div class="ui dropdown">
+    <div class="menu">
+      <div class="item clear-selection">clear</div>
+      <div class="item" data-value="..." data-scope="...">
+        <span class="item-check-mark">...</span>
+        ...
+      </div>
+    </div>
+  </div>
+  <div class="ui list">
+    <span class="item empty-list">no item</span>
+    <span class="item">...</span>
+  </div>
+</div>
+```
+
+When the selected items change, the `combo-value` input will be updated.
+If there is `data-update-url`, it also calls backend to attach/detach the changed items.
+
+Also, the changed items will be syncronized to the `ui list` items.
+
+The items with the same data-scope only allow one selected at a time.
diff --git a/web_src/js/features/repo-issue-sidebar.ts b/web_src/js/features/repo-issue-sidebar.ts
index 4a1ef02aab..52878848e8 100644
--- a/web_src/js/features/repo-issue-sidebar.ts
+++ b/web_src/js/features/repo-issue-sidebar.ts
@@ -3,7 +3,7 @@ import {POST} from '../modules/fetch.ts';
 import {updateIssuesMeta} from './repo-common.ts';
 import {svg} from '../svg.ts';
 import {htmlEscape} from 'escape-goat';
-import {toggleElem} from '../utils/dom.ts';
+import {queryElems, toggleElem} from '../utils/dom.ts';
 import {initIssueSidebarComboList, issueSidebarReloadConfirmDraftComment} from './repo-issue-sidebar-combolist.ts';
 
 function initBranchSelector() {
@@ -28,7 +28,7 @@ function initBranchSelector() {
     } else {
       // for new issue, only update UI&form, do not send request/reload
       const selectedHiddenSelector = this.getAttribute('data-id-selector');
-      document.querySelector(selectedHiddenSelector).value = selectedValue;
+      document.querySelector<HTMLInputElement>(selectedHiddenSelector).value = selectedValue;
       elSelectBranch.querySelector('.text-branch-name').textContent = selectedText;
     }
   });
@@ -53,7 +53,7 @@ function initListSubmits(selector, outerSelector) {
         for (const [elementId, item] of itemEntries) {
           await updateIssuesMeta(
             item['update-url'],
-            item.action,
+            item['action'],
             item['issue-id'],
             elementId,
           );
@@ -80,14 +80,14 @@ function initListSubmits(selector, outerSelector) {
       if (scope) {
         // Enable only clicked item for scoped labels
         if (this.getAttribute('data-scope') !== scope) {
-          return true;
+          return;
         }
         if (this !== clickedItem && !this.classList.contains('checked')) {
-          return true;
+          return;
         }
       } else if (this !== clickedItem) {
         // Toggle for other labels
-        return true;
+        return;
       }
 
       if (this.classList.contains('checked')) {
@@ -258,13 +258,13 @@ export function initRepoIssueSidebar() {
   initRepoIssueDue();
 
   // TODO: refactor the legacy initListSubmits&selectItem to initIssueSidebarComboList
-  initListSubmits('select-label', 'labels');
   initListSubmits('select-assignees', 'assignees');
   initListSubmits('select-assignees-modify', 'assignees');
+  selectItem('.select-assignee', '#assignee_id');
+
   selectItem('.select-project', '#project_id');
   selectItem('.select-milestone', '#milestone_id');
-  selectItem('.select-assignee', '#assignee_id');
 
-  // init the combo list: a dropdown for selecting reviewers, and a list for showing selected reviewers and related actions
-  initIssueSidebarComboList(document.querySelector('.issue-sidebar-combo[data-sidebar-combo-for="reviewers"]'));
+  // init the combo list: a dropdown for selecting items, and a list for showing selected items and related actions
+  queryElems<HTMLElement>(document, '.issue-sidebar-combo', (el) => initIssueSidebarComboList(el));
 }
diff --git a/web_src/js/features/repo-issue.ts b/web_src/js/features/repo-issue.ts
index 92916ec8d7..7457531ece 100644
--- a/web_src/js/features/repo-issue.ts
+++ b/web_src/js/features/repo-issue.ts
@@ -98,6 +98,7 @@ export function initRepoIssueSidebarList() {
     });
   });
 
+  // FIXME: it is wrong place to init ".ui.dropdown.label-filter"
   $('.menu .ui.dropdown.label-filter').on('keydown', (e) => {
     if (e.altKey && e.key === 'Enter') {
       const selectedItem = document.querySelector('.menu .ui.dropdown.label-filter .menu .item.selected');
@@ -106,7 +107,6 @@ export function initRepoIssueSidebarList() {
       }
     }
   });
-  $('.ui.dropdown.label-filter, .ui.dropdown.select-label').dropdown('setting', {'hideDividers': 'empty'}).dropdown('refreshItems');
 }
 
 export function initRepoIssueCommentDelete() {
@@ -652,19 +652,6 @@ function initIssueTemplateCommentEditors($commentForm) {
   }
 }
 
-// This function used to show and hide archived label on issue/pr
-//  page in the sidebar where we select the labels
-//  If we have any archived label tagged to issue and pr. We will show that
-//  archived label with checked classed otherwise we will hide it
-//  with the help of this function.
-//  This function runs globally.
-export function initArchivedLabelHandler() {
-  if (!document.querySelector('.archived-label-hint')) return;
-  for (const label of document.querySelectorAll('[data-is-archived]')) {
-    toggleElem(label, label.classList.contains('checked'));
-  }
-}
-
 export function initRepoCommentFormAndSidebar() {
   const $commentForm = $('.comment.form');
   if (!$commentForm.length) return;
diff --git a/web_src/js/index.ts b/web_src/js/index.ts
index 487aac97aa..eeead37333 100644
--- a/web_src/js/index.ts
+++ b/web_src/js/index.ts
@@ -30,7 +30,7 @@ import {
   initRepoIssueWipTitle,
   initRepoPullRequestMergeInstruction,
   initRepoPullRequestAllowMaintainerEdit,
-  initRepoPullRequestReview, initRepoIssueSidebarList, initArchivedLabelHandler,
+  initRepoPullRequestReview, initRepoIssueSidebarList,
 } from './features/repo-issue.ts';
 import {initRepoEllipsisButton, initCommitStatuses} from './features/repo-commit.ts';
 import {initRepoTopicBar} from './features/repo-home.ts';
@@ -182,7 +182,6 @@ onDomReady(() => {
     initRepoIssueContentHistory,
     initRepoIssueList,
     initRepoIssueSidebarList,
-    initArchivedLabelHandler,
     initRepoIssueReferenceRepositorySearch,
     initRepoIssueTimeTracking,
     initRepoIssueWipTitle,
diff --git a/web_src/js/utils/dom.ts b/web_src/js/utils/dom.ts
index 79ce05a7ad..29b34dd1e3 100644
--- a/web_src/js/utils/dom.ts
+++ b/web_src/js/utils/dom.ts
@@ -3,7 +3,7 @@ import type {Promisable} from 'type-fest';
 import type $ from 'jquery';
 
 type ElementArg = Element | string | NodeListOf<Element> | Array<Element> | ReturnType<typeof $>;
-type ElementsCallback = (el: Element) => Promisable<any>;
+type ElementsCallback<T extends Element> = (el: T) => Promisable<any>;
 type ElementsCallbackWithArgs = (el: Element, ...args: any[]) => Promisable<any>;
 type ArrayLikeIterable<T> = ArrayLike<T> & Iterable<T>; // for NodeListOf and Array
 
@@ -58,7 +58,7 @@ export function isElemHidden(el: ElementArg) {
   return res[0];
 }
 
-function applyElemsCallback<T extends Element>(elems: ArrayLikeIterable<T>, fn?: ElementsCallback): ArrayLikeIterable<T> {
+function applyElemsCallback<T extends Element>(elems: ArrayLikeIterable<T>, fn?: ElementsCallback<T>): ArrayLikeIterable<T> {
   if (fn) {
     for (const el of elems) {
       fn(el);
@@ -67,7 +67,7 @@ function applyElemsCallback<T extends Element>(elems: ArrayLikeIterable<T>, fn?:
   return elems;
 }
 
-export function queryElemSiblings<T extends Element>(el: Element, selector = '*', fn?: ElementsCallback): ArrayLikeIterable<T> {
+export function queryElemSiblings<T extends Element>(el: Element, selector = '*', fn?: ElementsCallback<T>): ArrayLikeIterable<T> {
   const elems = Array.from(el.parentNode.children) as T[];
   return applyElemsCallback<T>(elems.filter((child: Element) => {
     return child !== el && child.matches(selector);
@@ -75,13 +75,13 @@ export function queryElemSiblings<T extends Element>(el: Element, selector = '*'
 }
 
 // it works like jQuery.children: only the direct children are selected
-export function queryElemChildren<T extends Element>(parent: Element | ParentNode, selector = '*', fn?: ElementsCallback): ArrayLikeIterable<T> {
+export function queryElemChildren<T extends Element>(parent: Element | ParentNode, selector = '*', fn?: ElementsCallback<T>): ArrayLikeIterable<T> {
   return applyElemsCallback<T>(parent.querySelectorAll(`:scope > ${selector}`), fn);
 }
 
 // it works like parent.querySelectorAll: all descendants are selected
 // in the future, all "queryElems(document, ...)" should be refactored to use a more specific parent
-export function queryElems<T extends Element>(parent: Element | ParentNode, selector: string, fn?: ElementsCallback): ArrayLikeIterable<T> {
+export function queryElems<T extends Element>(parent: Element | ParentNode, selector: string, fn?: ElementsCallback<T>): ArrayLikeIterable<T> {
   return applyElemsCallback<T>(parent.querySelectorAll(selector), fn);
 }