code.gitea.io/gitea@v1.22.3/docs/content/contributing/guidelines-frontend.en-us.md (about)

     1  ---
     2  date: "2021-10-13T16:00:00+02:00"
     3  title: "Guidelines for Frontend Development"
     4  slug: "guidelines-frontend"
     5  sidebar_position: 30
     6  toc: false
     7  draft: false
     8  aliases:
     9    - /en-us/guidelines-frontend
    10  menu:
    11    sidebar:
    12      parent: "contributing"
    13      name: "Guidelines for Frontend"
    14      sidebar_position: 30
    15      identifier: "guidelines-frontend"
    16  ---
    17  
    18  # Guidelines for Frontend Development
    19  
    20  ## Background
    21  
    22  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.
    23  
    24  The HTML pages are rendered by [Go HTML Template](https://pkg.go.dev/html/template).
    25  
    26  The source files can be found in the following directories:
    27  
    28  * **CSS styles:** `web_src/css/`
    29  * **JavaScript files:** `web_src/js/`
    30  * **Vue components:** `web_src/js/components/`
    31  * **Go HTML templates:** `templates/`
    32  
    33  ## General Guidelines
    34  
    35  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)
    36  
    37  ### Gitea specific guidelines
    38  
    39  1. Every feature (Fomantic-UI/jQuery module) should be put in separate files/directories.
    40  2. HTML ids and classes should use kebab-case, it's preferred to contain 2-3 feature related keywords.
    41  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.
    42  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.
    43  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.
    44  6. Simple pages and SEO-related pages use Go HTML Template render to generate static Fomantic-UI HTML output. Complex pages can use Vue3.
    45  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)`.
    46  8. Use semantic elements, prefer `<button class="ui button">` instead of `<div class="ui button">`.
    47  9. Avoid unnecessary `!important` in CSS, add comments to explain why it's necessary if it can't be avoided.
    48  10. Avoid mixing different events in one event listener, prefer to use individual event listeners for every event.
    49  11. Custom event names are recommended to use `ce-` prefix.
    50  12. Prefer using Tailwind CSS which is available via `tw-` prefix, e.g. `tw-relative`. Gitea's helper CSS classes use `gt-` prefix (`gt-word-break`), while Gitea's own private framework-level CSS classes use `g-` prefix (`g-modal-confirm`).
    51  13. Avoid inline scripts & styles as much as possible, it's recommended to put JS code into JS files and use CSS classes. If inline scripts & styles are unavoidable, explain the reason why it can't be avoided.
    52  
    53  ### Accessibility / ARIA
    54  
    55  In history, Gitea heavily uses Fomantic UI which is not an accessibility-friendly framework.
    56  Gitea uses some patches to make Fomantic UI more accessible (see `aria.md` and related JS files),
    57  but there are still many problems which need a lot of work and time to fix.
    58  
    59  ### Framework Usage
    60  
    61  Mixing different frameworks together is discouraged, it makes the code difficult to be maintained.
    62  A JavaScript module should follow one major framework and follow the framework's best practice.
    63  
    64  Recommended implementations:
    65  
    66  * Vue + Vanilla JS
    67  * Fomantic-UI (jQuery)
    68  * htmx (partial page reloads for otherwise static components)
    69  * Vanilla JS
    70  
    71  Discouraged implementations:
    72  
    73  * Vue + Fomantic-UI (jQuery)
    74  * jQuery + Vanilla JS
    75  * htmx + any other framework which requires heavy JS code, or unnecessary features like htmx scripting (`hx-on`)
    76  
    77  To make UI consistent, Vue components can use Fomantic-UI CSS classes.
    78  We use htmx for simple interactions. You can see an example for simple interactions where htmx should be used in this [PR](https://github.com/go-gitea/gitea/pull/28908). Do not use htmx if you require more advanced reactivity, use another framework (Vue/Vanilla JS).
    79  Although mixing different frameworks is discouraged,
    80  it should also work if the mixing is necessary and the code is well-designed and maintainable.
    81  
    82  ### `async` Functions
    83  
    84  Only mark a function as `async` if and only if there are `await` calls
    85  or `Promise` returns inside the function.
    86  
    87  It's not recommended to use `async` event listeners, which may lead to problems.
    88  The reason is that the code after await is executed outside the event dispatch.
    89  Reference: https://github.com/github/eslint-plugin-github/blob/main/docs/rules/async-preventdefault.md
    90  
    91  If an event listener must be `async`, the `e.preventDefault()` should be before any `await`,
    92  it's recommended to put it at the beginning of the function.
    93  
    94  If we want to call an `async` function in a non-async context,
    95  it's recommended to use `const _promise = asyncFoo()` to tell readers
    96  that this is done by purpose, we want to call the async function and ignore the Promise.
    97  Some lint rules and IDEs also have warnings if the returned Promise is not handled.
    98  
    99  ### Fetching data
   100  
   101  To fetch data, use the wrapper functions `GET`, `POST` etc. from `modules/fetch.js`. They
   102  accept a `data` option for the content, will automatically set CSRF token and return a
   103  Promise for a [Response](https://developer.mozilla.org/en-US/docs/Web/API/Response).
   104  
   105  ### HTML Attributes and `dataset`
   106  
   107  The usage of `dataset` is forbidden, its camel-casing behaviour makes it hard to grep for attributes.
   108  However, there are still some special cases, so the current guideline is:
   109  
   110  * For legacy code:
   111    * `$.data()` should be refactored to `$.attr()`.
   112    * `$.data()` can be used to bind some non-string data to elements in rare cases, but it is highly discouraged.
   113  
   114  * For new code:
   115    * `node.dataset` should not be used, use `node.getAttribute` instead.
   116    * never bind any user data to a DOM node, use a suitable design pattern to describe the relation between node and data.
   117  
   118  ### Show/Hide Elements
   119  
   120  * Vue components are recommended to use `v-if` and `v-show` to show/hide elements.
   121  * Go template code should use `.tw-hidden` and `showElem()/hideElem()/toggleElem()`, see more details in `.tw-hidden`'s comment.
   122  
   123  ### Styles and Attributes in Go HTML Template
   124  
   125  It's recommended to use:
   126  
   127  ```html
   128  <div class="gt-name1 gt-name2 {{if .IsFoo}}gt-foo{{end}}" {{if .IsFoo}}data-foo{{end}}></div>
   129  ```
   130  
   131  instead of:
   132  
   133  ```html
   134  <div class="gt-name1 gt-name2{{if .IsFoo}} gt-foo{{end}}"{{if .IsFoo}} data-foo{{end}}></div>
   135  ```
   136  
   137  to make the code more readable.
   138  
   139  ### Legacy Code
   140  
   141  A lot of legacy code already existed before this document's written. It's recommended to refactor legacy code to follow the guidelines.
   142  
   143  ### Vue3 and JSX
   144  
   145  Gitea is using Vue3 now. We decided not to introduce JSX to keep the HTML and the JavaScript code separated.
   146  
   147  ### UI Examples
   148  
   149  Gitea uses some self-made UI elements and customizes others to integrate them better into the general UI approach. When running Gitea in development mode (`RUN_MODE=dev`), a page with some standardized UI examples is available under `http(s)://your-gitea-url:port/devtest`.