stencil-tailwind-plugin

#
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!npm

This package is used to integrate tailwindcss and StencilJS. The versions this package supports:
| Tailwind CSS Version | Package Version |
| -------------------- | --------------- |
| v4 | v2.x (main) |
| v3 | v1.x |
| v2 | v0.x |

This plugin is aimed at using the CSS-based tailwind configuration. The setup of the plugin assumes the CSS configuration system is being used. Please refer to the Tailwind documentation on configuration options of Tailwind from CSS. See the upgrade guide for details.

For an example of a basic Stencil integration, see the example.

Getting started

This guide assumes that a Stencil project has already been initialized and configured.

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Install the necessary dependencies:
``bash
npm install -D stencil-tailwind-plugin tailwindcss @tailwindcss/postcss
`

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In the Stencil configuration, consume the plugin:
`ts
// stencil.config.ts
import { Config } from '@stencil/core';
import tailwind from 'stencil-tailwind-plugin';

export const config: Config = {
plugins: [
tailwind()
],
devServer: {
reloadStrategy: 'pageReload'
}
};
`

In some configurations, the reloadStrategy can be left as hmr but on occasions new styles are not applied as expected. For more on HMR, see below.

There are also a number of options that can be given to the plugin:

| Property | Description | Default |
| ----------------- | --------------------------------------------------------- | ------------ |
| enableDebug | Enables debugging | false |
| tailwindCssPath | Path to a css file to read for tailwind css configuration. When not specified a default @import "tailwindcss"; is used | undefined |
| injectTailwindConfiguration | Configuration object to be used for tailwind processing | undefined |
| stripComments | Indicate if the comment headers should be stripped as well | false |
| minify | Indicate if the css should be minified by Tailwind | true |
| optimise | Indicate if the css should be optimised by Tailwind (css is not minified) Note if optimise and minify are set, configuration defaults to minify | false |

The default options can be referenced from the plugin as well:
`ts
// stencil.config.ts
import tailwind, { PluginOptions } from 'stencil-tailwind-plugin';

const options = {
...PluginOptions.DEFAULT,
stripComments: true
};

export const config: Config = {
// ...
plugins: [
tailwind(options)
],
// ...
};
`

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There are 3 plugin's available:
- tailwind - the base tailwind style processor
- tailwindHMR - the tailwind Hot Module Reloader
- tailwindGlobal - handling global tailwind styles

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The plugin has a global option setter, which means configuration can be set globally instead of locally for each plugin type.

The configuration of the options can be done as such:
`ts
// stencil.config.ts
import tailwind, { setPluginConfigurationDefaults, tailwindGlobal, tailwindHMR } from 'stencil-tailwind-plugin';

const options = {
stripComments: true
};

setPluginConfigurationDefaults(options);

export const config: Config = {
// ...
plugins: [
tailwindGlobal(),
tailwind(),
tailwindHMR()
],
// ...
};
`

All the plugins that are not provided configuration will receive the configuration from setPluginConfigurationDefaults. This does not preclude setting different options per plugin:
`ts
// stencil.config.ts
import tailwind, { setPluginConfigurationDefaults, tailwindGlobal, tailwindHMR } from 'stencil-tailwind-plugin';

const opts = {
stripComments: true,
minify: true
};

setPluginConfigurationDefaults(opts);

export const config: Config = {
// ...
plugins: [
tailwindGlobal(),
tailwind(),
tailwindHMR({
...opts,
minify: false
})
],
// ...
};
`

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There can be situations whereby a Tailwind configuration needs to be applied to a specific file/component. This can be accomplished by providing a configuration function rather than a configuration object. In the examples above and object is used, but in this scenario we will configure the plugin with a function:
`ts
// stencil.config.ts
import tailwind, { TailwindConfig } from 'stencil-tailwind-plugin';

const twConfigurationFn = (filename: string) => {
if (filename.includes('the-chosen-one.tsx')) {
return '@import "friendly-font-face"; @import "taiwindcss";';
}
return '@import "tailwindcss"';
};

const opts = {
injectTailwindConfiguration: twConfigurationFn
};

export const config: Config = {
// ...
plugins: [
tailwind(opts)
],
// ...
};
`

In the above code injectTailwindConfiguration is given a callback function to be able to return the Tailwind configuration CSS that'll be used for the file. The argument filename is the full path to the component that will be processed by Tailwind processor.

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The file being processed will be the raw file for StencilJS compiler. This means the filename will contain query parameters as well:
`
some-component.scss?tag=some-component
`

The example about merely checks the includes option as this negates the use of tags by StencilJS.

If there are multiple distributions enabled in the StencilJS configuration, then the configuration function will be called multiple times. StencilJS handles each distribution output separately so each time a file is processed per distribution the configuration is required for that distribution. Presently there is no indication of which distribution Stencil is processing so configuration per file per distribution output is not possible.

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There are a number of postcss plugins that might be wanted when processing the tailwind output specifically. The nature of the stencil build makes it difficult to pass the custom css directly back into the css pipeline building. Hence, the postcss configuration can be completely overridden by creating a postcss configuration file.

The plugin uses the default postcss-load-config package. Hence, any the configuration options can be used as a file.

As an example of a postcss configuration that could be used:
`js
// postcss.config.js
module.exports = {
plugins: [
require('postcss-import'),
require('tailwindcss'),
require('postcss-sort-media-queries'),
require('postcss-combine-duplicated-selectors'),
require('cssnano')
]
};
`

If the tailwindcss plugin is not specified, it is assumed that the plugins should be run _before_ the default tailwind options. The tailwindcss plugin options will be overwritten by the tailwind configuration provided by the plugin, hence, the postcss tailwindcss is used as a marker for where tailwindcss should be used in the postcss chain of plugins.

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It is important to note that when using sass files, that the sass Stencil plugin appears before the tailwind plugin. The sass plugin needs to process the sass files first before the raw css is pasted to the tailwind postcss processor. An example configuration could look like:
`ts
// stencil.config.ts
import { Config } from '@stencil/core';
import { sass } from '@stencil/sass';
import tailwind from 'stencil-tailwind-plugin';
import { inlineSvg } from 'stencil-inline-svg';

export const config: Config = {
outputTargets: [ / ... /],
plugins: [
inlineSvg(),
sass({
includePaths: [
/ ... /
]
}),
tailwind(),
]
`

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Stencil's compiler does support HMR, however, for inline styles produced by tailwind, another plugin is required in order for the correct dependencies to be mapped to the file watcher. The HMR plugin can be included by:
`ts
// stencil.config.ts
import { Config } from '@stencil/core';
import tailwind, { tailwindHMR } from 'stencil-tailwind-plugin';
import tailwindConfig from './tailwind.config';

export const config: Config = {
// ...
plugins: [
sass(),
tailwind(),
tailwindHMR(),
],
};
`

The tailwindHMR plugin will register all the tsx files against the css files. This allows Stencil to watch for changes on those tsx files and update the css accordingly.

The HMR ability of Stencil and Web Components makes changes difficult, and generally a page reload is required.

Unfortunately, as of v2.12.0 of the Stencil compiler, this cannot be done as a single plugin and two plugins are required.

Global styles with @apply

With the new CSS based configuration, usage of @apply is discouraged by the Tailwind community.

Caveat on Function Components (1)

There are some issues around functional components when they are located in external files to a component. The plugin attempts to insert the Function Component styles into the host component and in so doing, the Stencil HMR does not detect the changes correctly and will require a rebuild when this happens.

As an example, given:
`tsx
// component-A.tsx
import { FuncComp } from '../common/UtilsFunctionalComponents'

// rest of the normal component that uses
`
And:
`tsx
// component-B.tsx
import { FuncComp } from '../common/UtilsFunctionalComponents'

// rest of the normal component that uses
`
And:
`tsx
// common/UtilsFunctionalComponents.tsx
export const FuncComp: FunctionalComponent = ({ name }) => (


This is a functional one - Hello, {name}!


);
`

In this example, component-A and component-B will both contain the style definition for text-indigo-700 because they both import FuncComp.

If common/UtilsFunctionalComponents.tsx is updated, neither component-A.tsx or component-B.tsx will be build by Stencil's HMR, hence the style class change from FuncComp will not reflect.

Caveat on Function Components (2)

Functional components can be composed of other functional components. However, there is a known issue where the subsequent functional component (the component that is being used inside the functional component) will not generate any styles. The styles are only generated for the first level of functional components. This is due to the way the Stencil compiler handles stylesheets and functional component building.

Peer Dependencies

This plugin requires the following peer dependencies:
- @tailwindcss/postcss
- tailwindcss
- typescript

These are provided as peer dependencies so consumers can override the versions.

Development

Clone the repo and install the dependencies:
`bash
pnpm install
`

Run tests:
`bash
pnpm tests
`

Honourable mentions

A lot of inspiration for this plugin was taken from the similarly named plugin, stencil-tailwind by Jack Rowlingson.

Inspiration also taken from proto-stencil-tailwind that moves stencil-tailwind forward by Richard Hess.

Special thanks to the above.

Other options

For other ways of integrating Tailwind into your project, Anthony Giuliano wrote a blog post:

https://ionicframework.com/blog/how-to-integrate-tailwind-css-into-your-stencil-project/




Upgrade Guide from v1 to v2

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v2 uses the postcss plugin for tailwind more directly than v1. Install the @tailwindcss/postcss:
`
npm install -D @tailwindcss/postcss
`

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The configuration structure has changed for the new Tailwind v4 configuration in CSS.

#### Deprecated options
- tailwindCssContents (see injectTailwindConfiguration)
- tailwindConf (see injectTailwindConfiguration)
- useAutoPrefixer (default Tailwind uses autoprefixer internally)
- postcss (removed)

#### New options
- injectTailwindConfiguration - returns the configuration CSS for tailwind
- optimise - passed to Tailwind to optimise the output without minification. See Tailwind documentation.

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There are numerous type renames. The generally exposed versions are:
- PluginConfigOptsDefaults renamed to PluginConfigOptionsDefaults
- PluginConfigOpts renamed to PluginConfigurationOptions

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- PluginOpts renamed to PluginOptions`