[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

custom/conf/app.ini.sample

 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.

docs/content/doc/advanced/config-cheat-sheet.en-us.md

 - `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.

docs/content/doc/advanced/customizing-gitea.en-us.md

 
 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.  

integrations/issue_test.go

 	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)()
 

modules/auth/repo_form.go

 
 // 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

modules/setting/setting.go

 		DefaultShowFullName   bool
 		DefaultTheme          string
 		Themes                []string
+		Reactions             []string
 		SearchRepoDescription bool
 		UseServiceWorker      bool
 
 		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

routers/repo/issue.go

 		}
 	}
 	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()))
 
 	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)
 
 	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)

routers/repo/pull.go

 
 	ctx.Data["NumCommits"] = compareInfo.Commits.Len()
 	ctx.Data["NumFiles"] = compareInfo.NumFiles
+	ctx.Data["AllowedReactions"] = setting.UI.Reactions
 	return compareInfo
 }
 

templates/repo/diff/comments.tmpl

 		{{$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>

templates/repo/issue/view_content.tmpl

 					{{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}}
 					{{$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}}

templates/repo/issue/view_content/add_reaction.tmpl

 	<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}}

templates/repo/issue/view_content/comments.tmpl

 									{{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}}
 				{{$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}}

templates/repo/issue/view_content/reactions.tmpl

 	<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}}