Improve the frontend guideline

docs/content/doc/developers/guidelines-frontend.en-us.md

@@ -47,6 +47,8 @@ We recommend [Google HTML/CSS Style Guide](https://google.github.io/styleguide/h
 7. Clarify variable types, prefer `elem.disabled = true` instead of `elem.setAttribute('disabled', 'anything')`, prefer `$el.prop('checked', var === 'yes')` instead of `$el.prop('checked', var)`.
 8. Use semantic elements, prefer `<button class="ui button">` instead of `<div class="ui button">`.
 9. Avoid unnecessary `!important` in CSS, add comments to explain why it's necessary if it can't be avoided.
+10. Avoid mixing different events in one event listener, prefer to use individual event listeners for every event.
+11. Custom event names are recommended to use `ce-` prefix.
 
 ### Accessibility / ARIA
 
@@ -109,6 +111,22 @@ However, there are still some special cases, so the current guideline is:
 * Vue components are recommended to use `v-if` and `v-show` to show/hide elements.
 * Go template code should use Gitea's `.gt-hidden` and `showElem()/hideElem()/toggleElem()`, see more details in `.gt-hidden`'s comment.
 
+### Styles and Attributes in Go HTML Template
+
+It's recommended to use:
+
+```html
+<div class="gt-name1 gt-name2 {{if .IsFoo}}gt-foo{{end}}" {{if .IsFoo}}data-foo{{end}}></div>
+```
+
+instead of:
+
+```html
+<div class="gt-name1 gt-name2{{if .IsFoo}} gt-foo{{end}}"{{if .IsFoo}} data-foo{{end}}></div>
+```
+
+to make the code more readable.
+
 ### Legacy Code
 
 A lot of legacy code already existed before this document's written. It's recommended to refactor legacy code to follow the guidelines.

web_src/js/components/ContextPopup.vue

@@ -87,7 +87,7 @@ export default {
     }
   },
   mounted() {
-    this.$refs.root.addEventListener('us-load-context-popup', (e) => {
+    this.$refs.root.addEventListener('ce-load-context-popup', (e) => {
       const data = e.detail;
       if (!this.loading && this.issue === null) {
         this.load(data);

web_src/js/features/contextpopup.js

@@ -32,7 +32,7 @@ export function initContextPopups() {
       content: el,
       interactive: true,
       onShow: () => {
-        el.firstChild.dispatchEvent(new CustomEvent('us-load-context-popup', {detail: {owner, repo, index}}));
+        el.firstChild.dispatchEvent(new CustomEvent('ce-load-context-popup', {detail: {owner, repo, index}}));
       }
     });
   });