voks

deno.land/x version npm version

voks [ˈvokʃ], danish for wax, is a minimal, yet powerful enough templating language based on Javascript Template Literals. It provides the ability to define and compose typescript checked components, while not losing the flexibility of html declarations.

Rendering speed is not the foremost goal of this library, as I see most performance problems not in the rendering layer of classical web application frameworks but in overly excessive use of javascript in the frontend.

Release History

https://github.com/voks-templating/voks/releases

API

For details see: https://deno.land/x/voks/mod.ts

  • html - tagged template literal function to declare simple minimal components
  • attr - function to declare dynamic html attributes with escaped values
  • renderToString - renders given html template components to a string. The complete template will be resolved before
  • renderToStream - writes the template parts to the stream, once ready. Waits for async content, which results in iterative “write when ready” rendering.

Usage

deno

Deno is written in deno so that it is a deno first class reptile citizen.

To have a better understanding of how things work, please give a look to the examples. But the code below shows the basic usage:

import {
  html,
  HTMLTemplate,
  renderToStream,
} from "https://deno.land/x/voks/mod.ts";

const viewComponent = (content: HTMLTemplate) =>
  html`<p>${"hello"}</p> <p>${asyncFunc("world!")}</p>`;

await renderToStream(
  Deno.stdout,
  viewComponent,
);

The above results in proper stream rendering to the clients, allowing the browser client to show content, that is available already, and waiting for content, not yet available.

This allows some fancy stuff like aborting such calls, when they take too long, and replace them by client side islands, that translude that content at client time. (See the express example for more details about that.)

nodejs

voks is beeing built for nodejs with esbuild with esm module format targeting nodjs18.8 (see ./scripts/build.node.ts).

Install voks as npm dependency:

npm i --save @voks/voks

Example Usage:

import { attr, html, renderToString } from "voks";

const template = html`<div ${[
  attr("class", "fubar"),
  attr("checked", true),
]} />`;

const res = await renderToString(template);
console.log(res);

Attributes

Attribute Value Types

String Attributes

value will be HTML escaped, so you can safely pass user input to it. (see Content Escaping.

The handling as string (inclusively the escaping) is the default behaviour, so numbers, symbols and everything not described here will be escaped.

attr('name', 'value')
// => name="value"

Boolean

value will not be rendered. Boolean attributes will be handled as standalone flag attributes.

attr('checked', true)
// => checked

Object Literals and Arrays

Object-Literals and Arrays will be stringified with JSON.stringify and HTML escaped. So parsing those values requires to unescape the HTML escaping and afterwards to pass it to JSON.parse. (see Content Escaping.

Object Literal Attributes

If you want to render attributes from an object literal, you can just pass it to the string literal, and it will be automatically converted to a list of Template Attributes.

const min = 7;
const range = (min) =>
  html`<input type="range" ${{ min, checked: true, dataMessage: "hello" }}`;
// => <input type="range" min="7" checked data-message="hello">

Content Escaping

All keys passed to the html tagged template function are escaped when they are not itself generators. If you pass a generator function itself it has to escape content, when before passing it to yield.

It can be considered as safe to pass html generators as keys.

renderToStream(html`<div>${"<script>console.log("hello, world!")</script>"}</div>`) # => "<div>&lt;script&gt;console.log(&quot;hello, world!&quot;)&lt;/script&gt;</div>"

renderToStream(html`<div>${html`<script>console.log("hello, world!")</script>`}</div>`) # => "<div><script>console.log("hello, world!")</script></div>"

In the process of the escaping, &, ", ', <, and > are replaced by their HTML entity equivalents (&amp;,&quot;,&#39;,&lt;,&gt;).

Attributes and Escaping

If you want to render attributes in a conditional or dynamic manner, you cannot rely on plain template literals as they would be escaped. So the following example will not work properly.

const range = (min) => html`<input type="range" ${min !== undefined ? `min="${min}"` : ''}` ⚡️

There is an specific TemplateAttribute type that can be created using the attr() function.

So if you want to render dynamic properties as a template literal value you need to use the attr function.

const range = (min) => html`<input type="range" ${attr('min', min)}`

Raw Content

If you want to render raw content, you can use the raw function. It will bypass the html escaping and allow you to pass raw content to the template.

NOTE! Please have in mind that this is a potential a very high security risk, as it allows to inject arbitrary content into the template. So please use it with care. As a rule of thumb, only use it for content that is not user generated (e.g. loaded from db content, that has been entered by users in first place)

// raw content
html`<div ${raw(content)}></div>`;

// raw attribute values
html`<input type="text" ${attr("value", raw(value))} />`;

Contribution

Tasks

Tasks can be invoked with deno task [TASKNAME]:

  • deps:load - loads dependencies to deno cache if dependencies have been updated remotely
  • run - kicks off the service
  • run:debug - starts the service in debug mode
  • run:example:synch - runs a synchronous rendering example
  • run:example:stream - runs a stream rendering example
  • run:example:express - starts an express app at localhost:3001, showing an example integration with fallback handling.

Settings

The project settings are set via environment variables. Please give a look to the .env.example file to see, which environment variables will be evaluated. To enable settings for your app, provide them in the run environment or create a .env file, likewise to the example file.

Testing

:)

deno test

Benchmarks

deno bench

License

Apache-2.0