element/examples/docs/en-US/custom-theme.md

Custom theme

Element uses BEM-styled CSS so that you can override styles easily. But if you need to replace styles at a large scale, e.g. change the theme color from blue to orange or green, maybe overriding them one by one is not a good idea, and this is where our theme customization tool kicks in.

Install related tool

First install the theme generator globally or locally. Local install is recommended because in this way, when others clone your project, npm will automatically install it for them.

npm i element-theme -g

Then install the default theme from npm or GitHub.

# from npm
npm i element-theme-default -D

# from GitHub
npm i https://github.com/ElementUI/theme-default -D

Initialize variable file

After successfully installing the above packages, a command named et is available in CLI (if the packages are installed locally, use node_modules/.bin/et instead). Run -i to initialize the variable file which outputs to element-variables.css by default. And you can specify its output directory as you will.

et -i [custom output file]

> ✔ Generator variables file

In element-variables.css you can find all the variables we used to style Element and they are defined in CSS4 style:

:root {

  /* Colors
  -------------------------- */
  --color-primary: #20a0ff;
  --color-success: #13ce66;
  --color-warning: #f7ba2a;
  --color-danger: #ff4949;
  --color-info: #50BFFF;
  --color-blue: #2e90fe;
  --color-blue-light: #5da9ff;
  --color-blue-lighter: rgba(var(--color-blue), 0.12);
  --color-white: #fff;
  --color-black: #000;
  --color-grey: #C0CCDA;

Modify variables

Just edit element-variables.css, e.g. changing the theme color to red:

--color-primary: red;

Build theme

After saving the variable file, use et to build your theme. You can activate watch mode by adding a parameter -w. And if you customized the variable file's output, you need to add a parameter -c and variable file's name:

et

> ✔ build theme font
> ✔ build element theme

Import custom theme

By default the build theme file is placed inside ./theme. You can specify its output directory with parameter -o. Importing your own theme is just like importing the default theme, only this time you import the file you just built:

import '../theme/index.css'
import ElementUI from 'element-ui'
import Vue from 'vue'

Vue.use(ElementUI)

Import component theme on demand

If you are using babel-plugin-component for on-demand import, just modify .babelrc and specify styleLibraryName to the path where your custom theme is located relative to .babelrc. Note that ~ is required:

{
  "plugins": [["component", [
    {
      "libraryName": "element-ui",
      "styleLibraryName": "~theme"
    }
  ]]]
}

If you are unfamiliar with babel-plugin-component, please refer to Quick Start. For more details, check out the project repository of element-theme.