Lume 1.14.0 is out

by Γ“scar Otero

4 min read

Lume 1.14.0 was released. This is a list of the main changes and new features.

New functions to (pre)process all pages at the same time

The functions site.process() and site.preprocess() are used to modify pages after or before rendering. For example, to process the HTML pages, you can do:

site.process([".html"], (page) => my_processor(page));

This callback is executed once per page, so if you have 200 pages, the callback is executed 200 times.

This is great to transform pages individually, but sometimes it's better to run the function only once to all pages at the same time. Two new functions were added for this purpose: processAll() and preprocessAll(). They are similar to process() and preprocess() but will receive all matched pages in the first argument:

site.processAll([".html"], (pages) => {
  pages.forEach((page) => my_processor(page));
  console.log(`Processed ${pages.length} HTML pages!`);

In previous versions, the only way to do something like that was through events like afterRender, beforeRender, beforeSave, etc. The advantage of using the new processAll and preprocessAll is they respect the order of the other processors:

site.process([".html"], first_processor);
site.processAll([".html"], second_processor);
site.process([".html"], third_processor);

In this example, second_processor is run after first_processor and before third_processor.

Introducing hooks

Hooks are functions registered by some plugins that can be invoked by other plugins or by yourself in the _config file. Hooks are stored in site.hooks and are useful to change a plugin configuration after the installation. For example, the postcss plugin sets the hook addPostcssPlugin. You can create a Lume plugin to, for example, minify the css code with CSS Nano:

import cssnano from "npm:cssnano@5.1.14";

export default function () {
  return (site) => {
    if (!site.hooks.addPostcssPlugin) {
      throw new Error("This plugin depends on postcss");


Now, you can use this plugin in the _config.ts file:

import lume from "lume/mod.ts";
import postcss from "lume/plugins/postcss.ts";
import nanocss from "./plugins/nanocss.ts";

const site = lume();


export default site;

Support for splitting mode for esbuild

Code splitting is a bundle technique that creates separate files with common code shared by multiple entry points. For example, if both entry points a.ts and b.ts imports c.ts, instead of including the c.ts code in both files (which would be duplicated), the code is saved into a chunk file that is imported by both files.

To generate the chunk files, we need to know all entry points first. But thanks to the implementation of processAll() function (previously explained) this is now possible in Lume. To enable the splitting mode, just need to configure the esbuild plugin in this way:

  options: {
    splitting: true,

Improved metas plugin

A couple of improvements have been added to metas:

No need for mergedKeys

The metas plugin needs a mergedKeys to customise the merging mode of the metas key:

  site: Site title
  icon: /img/icon.png
  lang: en

# Customise the merging mode of "metas"
  metas: object

You no longer need to add this value manually. The plugin inserts it automatically for you.

Field aliases

Field aliases are the new way to reuse a value in the metas. For example:

title: This is the title

  title: "=title" # Alias to the title value

Any value starting with = is considered an alias to another field. You can use dots for subvalues:

title: This is the title
  text: Page description
  title: "=title"
  description: "=intro.text"

Field aliases are way more powerful than the defaultPageData option of the plugin, which is deprecated and will be removed in the future.

  • Field aliases supports subvalues.
  • They can be configured at page or folder level with _data files.

Changes to prism plugin

The prism plugin now loads the Prism library from npm:. This change removes the languages option so if you need to load additional languages, you have to import them in your _config.ts file:

import lume from "lume/mod.ts";
import prism from "lume/plugins/prism.ts";

// Additional prism languages
import "npm:prismjs@1.29.0/components/prism-less.js";
import "npm:prismjs@1.29.0/components/prism-git.js";

const site = lume();

export default site;

The good news is you can also load plugins.

New plugin filter_pages

This plugin is the first step to deprecate the --dev mode of Lume (that ignores the pages with draft=true). The new plugin filter_pages filters pages using a callback and provides more flexibility. For example, let's say you want to ignore the draft pages in the production environment:

import lume from "lume/mod.ts";
import filter_pages from "lume/plugins/filter_pages.ts";

const site = lume();
const isProd = Deno.env.get("DENO_ENV") === "prod";

  fn: (page) => !isProd || !,

export default site;

See the file for the full list of changes.