- ---
- date: "2021-10-13T16:00:00+02:00"
- title: "Guidelines for Frontend Development"
- slug: "guidelines-frontend"
- sidebar_position: 30
- toc: false
- draft: false
- aliases:
- - /en-us/guidelines-frontend
- menu:
- sidebar:
- parent: "contributing"
- name: "Guidelines for Frontend"
- sidebar_position: 30
- identifier: "guidelines-frontend"
- ---
-
- # Guidelines for Frontend Development
-
- ## Background
-
- Gitea uses [Fomantic-UI](https://fomantic-ui.com/introduction/getting-started.html) (based on [jQuery](https://api.jquery.com)) and [Vue3](https://vuejs.org/) for its frontend.
-
- The HTML pages are rendered by [Go HTML Template](https://pkg.go.dev/html/template).
-
- The source files can be found in the following directories:
-
- * **CSS styles:** `web_src/css/`
- * **JavaScript files:** `web_src/js/`
- * **Vue components:** `web_src/js/components/`
- * **Go HTML templates:** `templates/`
-
- ## General Guidelines
-
- We recommend [Google HTML/CSS Style Guide](https://google.github.io/styleguide/htmlcssguide.html) and [Google JavaScript Style Guide](https://google.github.io/styleguide/jsguide.html)
-
- ### Gitea specific guidelines:
-
- 1. Every feature (Fomantic-UI/jQuery module) should be put in separate files/directories.
- 2. HTML ids and classes should use kebab-case, it's preferred to contain 2-3 feature related keywords.
- 3. HTML ids and classes used in JavaScript should be unique for the whole project, and should contain 2-3 feature related keywords. We recommend to use the `js-` prefix for classes that are only used in JavaScript.
- 4. CSS styling for classes provided by frameworks should not be overwritten. Always use new class names with 2-3 feature related keywords to overwrite framework styles. Gitea's helper CSS classes in `helpers.less` could be helpful.
- 5. The backend can pass complex data to the frontend by using `ctx.PageData["myModuleData"] = map[]{}`, but do not expose whole models to the frontend to avoid leaking sensitive data.
- 6. Simple pages and SEO-related pages use Go HTML Template render to generate static Fomantic-UI HTML output. Complex pages can use Vue3.
- 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.
- 12. Gitea's tailwind-style CSS classes use `gt-` prefix (`gt-relative`), while Gitea's own private framework-level CSS classes use `g-` prefix (`g-modal-confirm`).
-
- ### Accessibility / ARIA
-
- In history, Gitea heavily uses Fomantic UI which is not an accessibility-friendly framework.
- Gitea uses some patches to make Fomantic UI more accessible (see the `aria.js` and `aria.md`),
- but there are still many problems which need a lot of work and time to fix.
-
- ### Framework Usage
-
- Mixing different frameworks together is discouraged, it makes the code difficult to be maintained.
- A JavaScript module should follow one major framework and follow the framework's best practice.
-
- Recommended implementations:
-
- * Vue + Vanilla JS
- * Fomantic-UI (jQuery)
- * Vanilla JS
-
- Discouraged implementations:
-
- * Vue + Fomantic-UI (jQuery)
- * jQuery + Vanilla JS
-
- To make UI consistent, Vue components can use Fomantic-UI CSS classes.
- Although mixing different frameworks is discouraged,
- it should also work if the mixing is necessary and the code is well-designed and maintainable.
-
- ### `async` Functions
-
- Only mark a function as `async` if and only if there are `await` calls
- or `Promise` returns inside the function.
-
- It's not recommended to use `async` event listeners, which may lead to problems.
- The reason is that the code after await is executed outside the event dispatch.
- Reference: https://github.com/github/eslint-plugin-github/blob/main/docs/rules/async-preventdefault.md
-
- If an event listener must be `async`, the `e.preventDefault()` should be before any `await`,
- it's recommended to put it at the beginning of the function.
-
- If we want to call an `async` function in a non-async context,
- it's recommended to use `const _promise = asyncFoo()` to tell readers
- that this is done by purpose, we want to call the async function and ignore the Promise.
- Some lint rules and IDEs also have warnings if the returned Promise is not handled.
-
- ### HTML Attributes and `dataset`
-
- The usage of `dataset` is forbidden, its camel-casing behaviour makes it hard to grep for attributes.
- However, there are still some special cases, so the current guideline is:
-
- * For legacy code:
- * `$.data()` should be refactored to `$.attr()`.
- * `$.data()` can be used to bind some non-string data to elements in rare cases, but it is highly discouraged.
-
- * For new code:
- * `node.dataset` should not be used, use `node.getAttribute` instead.
- * never bind any user data to a DOM node, use a suitable design pattern to describe the relation between node and data.
-
- ### Show/Hide Elements
-
- * 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.
-
- ### Vue3 and JSX
-
- Gitea is using Vue3 now. We decided not to introduce JSX to keep the HTML and the JavaScript code separated.
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