[Feature] Custom Reactions (#8886)

* add [ui] Reactions

* move contend check from form to go functions

* use else if

* check if reaction is allowed only on react
(so previous custom reaction can be still removed)

* use $.AllowedReactions in templates

* use ctx.Flash.Error

* use it there too

* add redirection

* back to server error
because a wrong reaction is a template issue ...

* add emoji list link

* add docs entry

* small wording nit
suggestions from @jolheiser - thx

* same reactions as github

* fix PR reactions

* handle error so template JS could check

* Add Integrations Test

* add REACTIONS setting to cheat-sheet doc page

13 files changed, 76 insertions, 18 deletions

diff --git a/custom/conf/app.ini.sample b/custom/conf/app.ini.sample
index aa580e6a55..8d11cfc293 100644
--- a/custom/conf/app.ini.sample
+++ b/custom/conf/app.ini.sample
@@ -149,6 +149,9 @@ SHOW_USER_EMAIL = true
 DEFAULT_THEME = gitea
 ; All available themes. Allow users select personalized themes regardless of the value of `DEFAULT_THEME`.
 THEMES = gitea,arc-green
+; All available reactions. Allow users react with different emoji's
+: For the whole list look at https://gitea.com/gitea/gitea.com/issues/8
+REACTIONS = +1, -1, laugh, hooray, confused, heart, rocket, eyes
 ; Whether the full name of the users should be shown where possible. If the full name isn't set, the username will be used.
 DEFAULT_SHOW_FULL_NAME = false
 ; Whether to search within description at repository search on explore page.
diff --git a/docs/content/doc/advanced/config-cheat-sheet.en-us.md b/docs/content/doc/advanced/config-cheat-sheet.en-us.md
index 9fdcd2c82b..4fc8511b8c 100644
--- a/docs/content/doc/advanced/config-cheat-sheet.en-us.md
+++ b/docs/content/doc/advanced/config-cheat-sheet.en-us.md
@@ -118,6 +118,7 @@ Values containing `#` or `;` must be quoted using `` ` `` or `"""`.
 - `DEFAULT_THEME`: **gitea**: \[gitea, arc-green\]: Set the default theme for the Gitea install.
 - `THEMES`:  **gitea,arc-green**: All available themes. Allow users select personalized themes
   regardless of the value of `DEFAULT_THEME`.
+- `REACTIONS`: All available reactions. Allow users react with different emoji's.
 - `DEFAULT_SHOW_FULL_NAME`: **false**: Whether the full name of the users should be shown where possible. If the full name isn't set, the username will be used.
 - `SEARCH_REPO_DESCRIPTION`: **true**: Whether to search within description at repository search on explore page.
 - `USE_SERVICE_WORKER`: **true**: Whether to enable a Service Worker to cache frontend assets.
diff --git a/docs/content/doc/advanced/customizing-gitea.en-us.md b/docs/content/doc/advanced/customizing-gitea.en-us.md
index 362f4fb259..7c66991f69 100644
--- a/docs/content/doc/advanced/customizing-gitea.en-us.md
+++ b/docs/content/doc/advanced/customizing-gitea.en-us.md
@@ -161,6 +161,15 @@ Locales may change between versions, so keeping track of your customized locales
 
 To add a custom Readme, add a markdown formatted file (without an `.md` extension) to `custom/options/readme`
 
+### Reactions
+
+To change reaction emoji's you can set allowed reactions at app.ini
+```
+[ui]
+REACTIONS = +1, -1, laugh, confused, heart, hooray, eyes
+```
+A full list of supported emoji's is at [emoji list](https://gitea.com/gitea/gitea.com/issues/8)
+
 ## Customizing the look of Gitea
 
 As of version 1.6.0 Gitea has built-in themes. The two built-in themes are, the default theme `gitea`, and a dark theme `arc-green`. To change the look of your Gitea install change the value of `DEFAULT_THEME` in the [ui](https://docs.gitea.io/en-us/config-cheat-sheet/#ui-ui) section of `app.ini` to another one of the available options.  
diff --git a/integrations/issue_test.go b/integrations/issue_test.go
index 5a4b75b751..d46e35a946 100644
--- a/integrations/issue_test.go
+++ b/integrations/issue_test.go
@@ -194,6 +194,32 @@ func TestIssueCommentClose(t *testing.T) {
 	assert.Equal(t, "Description", val)
 }
 
+func TestIssueReaction(t *testing.T) {
+	defer prepareTestEnv(t)()
+	session := loginUser(t, "user2")
+	issueURL := testNewIssue(t, session, "user2", "repo1", "Title", "Description")
+
+	req := NewRequest(t, "GET", issueURL)
+	resp := session.MakeRequest(t, req, http.StatusOK)
+	htmlDoc := NewHTMLParser(t, resp.Body)
+
+	req = NewRequestWithValues(t, "POST", path.Join(issueURL, "/reactions/react"), map[string]string{
+		"_csrf":   htmlDoc.GetCSRF(),
+		"content": "8ball",
+	})
+	session.MakeRequest(t, req, http.StatusInternalServerError)
+	req = NewRequestWithValues(t, "POST", path.Join(issueURL, "/reactions/react"), map[string]string{
+		"_csrf":   htmlDoc.GetCSRF(),
+		"content": "eyes",
+	})
+	session.MakeRequest(t, req, http.StatusOK)
+	req = NewRequestWithValues(t, "POST", path.Join(issueURL, "/reactions/unreact"), map[string]string{
+		"_csrf":   htmlDoc.GetCSRF(),
+		"content": "eyes",
+	})
+	session.MakeRequest(t, req, http.StatusOK)
+}
+
 func TestIssueCrossReference(t *testing.T) {
 	defer prepareTestEnv(t)()
 
diff --git a/modules/auth/repo_form.go b/modules/auth/repo_form.go
index 1c873f2ea3..e3f6410c37 100644
--- a/modules/auth/repo_form.go
+++ b/modules/auth/repo_form.go
@@ -347,7 +347,7 @@ func (f *CreateCommentForm) Validate(ctx *macaron.Context, errs binding.Errors)
 
 // ReactionForm form for adding and removing reaction
 type ReactionForm struct {
-	Content string `binding:"Required;In(+1,-1,laugh,confused,heart,hooray)"`
+	Content string `binding:"Required"`
 }
 
 // Validate validates the fields
diff --git a/modules/setting/setting.go b/modules/setting/setting.go
index f2112f59f1..a97ab94677 100644
--- a/modules/setting/setting.go
+++ b/modules/setting/setting.go
@@ -169,6 +169,7 @@ var (
 		DefaultShowFullName   bool
 		DefaultTheme          string
 		Themes                []string
+		Reactions             []string
 		SearchRepoDescription bool
 		UseServiceWorker      bool
 
@@ -198,6 +199,7 @@ var (
 		MaxDisplayFileSize:  8388608,
 		DefaultTheme:        `gitea`,
 		Themes:              []string{`gitea`, `arc-green`},
+		Reactions:           []string{`+1`, `-1`, `laugh`, `hooray`, `confused`, `heart`, `rocket`, `eyes`},
 		Admin: struct {
 			UserPagingNum   int
 			RepoPagingNum   int
diff --git a/routers/repo/issue.go b/routers/repo/issue.go
index 739370da69..a2f4022a73 100644
--- a/routers/repo/issue.go
+++ b/routers/repo/issue.go
@@ -673,6 +673,7 @@ func ViewIssue(ctx *context.Context) {
 		}
 	}
 	ctx.Data["IssueWatch"] = iw
+	ctx.Data["AllowedReactions"] = setting.UI.Reactions
 
 	issue.RenderedContent = string(markdown.Render([]byte(issue.Content), ctx.Repo.RepoLink,
 		ctx.Repo.Repository.ComposeMetas()))
@@ -1447,6 +1448,12 @@ func ChangeIssueReaction(ctx *context.Context, form auth.ReactionForm) {
 
 	switch ctx.Params(":action") {
 	case "react":
+		if !util.IsStringInSlice(form.Content, setting.UI.Reactions) {
+			err := fmt.Errorf("ChangeIssueReaction: '%s' is not an allowed reaction", form.Content)
+			ctx.ServerError(err.Error(), err)
+			return
+		}
+
 		reaction, err := models.CreateIssueReaction(ctx.User, issue, form.Content)
 		if err != nil {
 			log.Info("CreateIssueReaction: %s", err)
@@ -1542,6 +1549,12 @@ func ChangeCommentReaction(ctx *context.Context, form auth.ReactionForm) {
 
 	switch ctx.Params(":action") {
 	case "react":
+		if !util.IsStringInSlice(form.Content, setting.UI.Reactions) {
+			err := fmt.Errorf("ChangeIssueReaction: '%s' is not an allowed reaction", form.Content)
+			ctx.ServerError(err.Error(), err)
+			return
+		}
+
 		reaction, err := models.CreateCommentReaction(ctx.User, comment.Issue, comment, form.Content)
 		if err != nil {
 			log.Info("CreateCommentReaction: %s", err)
diff --git a/routers/repo/pull.go b/routers/repo/pull.go
index 0ff077b462..78406de8ac 100644
--- a/routers/repo/pull.go
+++ b/routers/repo/pull.go
@@ -422,6 +422,7 @@ func PrepareViewPullInfo(ctx *context.Context, issue *models.Issue) *git.Compare
 
 	ctx.Data["NumCommits"] = compareInfo.Commits.Len()
 	ctx.Data["NumFiles"] = compareInfo.NumFiles
+	ctx.Data["AllowedReactions"] = setting.UI.Reactions
 	return compareInfo
 }
 
diff --git a/templates/repo/diff/comments.tmpl b/templates/repo/diff/comments.tmpl
index cc62f19a32..d86cf4077d 100644
--- a/templates/repo/diff/comments.tmpl
+++ b/templates/repo/diff/comments.tmpl
@@ -38,7 +38,7 @@
 		{{$reactions := .Reactions.GroupByType}}
 		{{if $reactions}}
 			<div class="ui attached segment reactions">
-			{{template "repo/issue/view_content/reactions" Dict "ctx" $ "ActionURL" (Printf "%s/comments/%d/reactions" $.root.RepoLink .ID) "Reactions" $reactions }}
+			{{template "repo/issue/view_content/reactions" Dict "ctx" $ "ActionURL" (Printf "%s/comments/%d/reactions" $.root.RepoLink .ID) "Reactions" $reactions "AllowedReactions" $.AllowedReactions }}
 			</div>
 		{{end}}
 	</div>
diff --git a/templates/repo/issue/view_content.tmpl b/templates/repo/issue/view_content.tmpl
index 5b5d7c45d7..8490841f97 100644
--- a/templates/repo/issue/view_content.tmpl
+++ b/templates/repo/issue/view_content.tmpl
@@ -28,7 +28,7 @@
 					{{end}}
 						{{if not $.Repository.IsArchived}}
 							<div class="ui right actions">
-								{{template "repo/issue/view_content/add_reaction" Dict "ctx" $ "ActionURL" (Printf "%s/issues/%d/reactions" $.RepoLink .Issue.Index) }}
+								{{template "repo/issue/view_content/add_reaction" Dict "ctx" $ "ActionURL" (Printf "%s/issues/%d/reactions" $.RepoLink .Issue.Index) "AllowedReactions" $.AllowedReactions}}
 								{{template "repo/issue/view_content/context_menu" Dict "ctx" $ "item" .Issue "delete" false "diff" false }}
 							</div>
 						{{end}}
@@ -47,7 +47,7 @@
 					{{$reactions := .Issue.Reactions.GroupByType}}
 					{{if $reactions}}
 						<div class="ui attached segment reactions">
-							{{template "repo/issue/view_content/reactions" Dict "ctx" $ "ActionURL" (Printf "%s/issues/%d/reactions" $.RepoLink .Issue.Index) "Reactions" $reactions }}
+							{{template "repo/issue/view_content/reactions" Dict "ctx" $ "ActionURL" (Printf "%s/issues/%d/reactions" $.RepoLink .Issue.Index) "Reactions" $reactions "AllowedReactions" $.AllowedReactions}}
 						</div>
 					{{end}}
 					{{if .Issue.Attachments}}
diff --git a/templates/repo/issue/view_content/add_reaction.tmpl b/templates/repo/issue/view_content/add_reaction.tmpl
index 626db5c261..3bd64ff786 100644
--- a/templates/repo/issue/view_content/add_reaction.tmpl
+++ b/templates/repo/issue/view_content/add_reaction.tmpl
@@ -7,12 +7,15 @@
 	<div class="menu has-emoji">
 		<div class="header">{{ .ctx.i18n.Tr "repo.pick_reaction"}}</div>
 		<div class="divider"></div>
-		<div class="item" data-content="+1">:+1:</div>
-		<div class="item" data-content="-1">:-1:</div>
-		<div class="item" data-content="laugh">:laughing:</div>
-		<div class="item" data-content="confused">:confused:</div>
-		<div class="item" data-content="heart">:heart:</div>
-		<div class="item" data-content="hooray">:tada:</div>
+		{{range $value := .AllowedReactions}}
+			{{if eq $value "hooray"}}
+				<div class="item" data-content="hooray">:tada:</div>
+			{{else if eq $value "laugh"}}
+				<div class="item" data-content="laugh">:laughing:</div>
+			{{else}}
+				<div class="item" data-content="{{$value}}">:{{$value}}:</div>
+			{{end}}
+		{{end}}
 	</div>
 </div>
 {{end}}
diff --git a/templates/repo/issue/view_content/comments.tmpl b/templates/repo/issue/view_content/comments.tmpl
index 1ea626ab84..49d2e9bc5f 100644
--- a/templates/repo/issue/view_content/comments.tmpl
+++ b/templates/repo/issue/view_content/comments.tmpl
@@ -36,7 +36,7 @@
 									{{end}}
 								</div>
 							{{end}}
-							{{template "repo/issue/view_content/add_reaction" Dict "ctx" $ "ActionURL" (Printf "%s/comments/%d/reactions" $.RepoLink .ID) }}
+							{{template "repo/issue/view_content/add_reaction" Dict "ctx" $ "ActionURL" (Printf "%s/comments/%d/reactions" $.RepoLink .ID) "AllowedReactions" $.AllowedReactions}}
 							{{template "repo/issue/view_content/context_menu" Dict "ctx" $ "item" . "delete" true "diff" false }}
 						</div>
 					{{end}}
@@ -55,7 +55,7 @@
 				{{$reactions := .Reactions.GroupByType}}
 				{{if $reactions}}
 					<div class="ui attached segment reactions">
-						{{template "repo/issue/view_content/reactions" Dict "ctx" $ "ActionURL" (Printf "%s/comments/%d/reactions" $.RepoLink .ID) "Reactions" $reactions }}
+						{{template "repo/issue/view_content/reactions" Dict "ctx" $ "ActionURL" (Printf "%s/comments/%d/reactions" $.RepoLink .ID) "Reactions" $reactions "AllowedReactions" $.AllowedReactions}}
 					</div>
 				{{end}}
 				{{if .Attachments}}
diff --git a/templates/repo/issue/view_content/reactions.tmpl b/templates/repo/issue/view_content/reactions.tmpl
index f4810f4849..4837370d22 100644
--- a/templates/repo/issue/view_content/reactions.tmpl
+++ b/templates/repo/issue/view_content/reactions.tmpl
@@ -2,14 +2,14 @@
 	<a class="ui label basic{{if $value.HasUser $.ctx.SignedUserID}} blue{{end}}{{if not $.ctx.IsSigned}} disabled{{end}} has-emoji" data-title="{{$value.GetFirstUsers}}{{if gt ($value.GetMoreUserCount) 0}} {{ $.ctx.i18n.Tr "repo.reactions_more" $value.GetMoreUserCount}}{{end}}" data-content="{{ $key }}" data-action-url="{{ $.ActionURL }}">
 		{{if eq $key "hooray"}}
 			:tada:
+		{{else if eq $key "laugh"}}
+			:laughing:
 		{{else}}
-			{{if eq $key "laugh"}}
-				:laughing:
-			{{else}}
-				:{{$key}}:
-			{{end}}
+			:{{$key}}:
 		{{end}}
 		{{len $value}}
 	</a>
 {{end}}
-{{template "repo/issue/view_content/add_reaction" Dict "ctx" $.ctx "ActionURL" .ActionURL }}
+{{if $.AllowedReactions}}
+	{{template "repo/issue/view_content/add_reaction" Dict "ctx" $.ctx "ActionURL" .ActionURL "AllowedReactions" $.AllowedReactions}}
+{{end}}