precompiling_templates.md

🦉 Precompiling templates 🦉

Owl is designed to be used by the Odoo javascript framework. Since Odoo handles its assets in its own non standard way, it was decided/assumed that Owl would compile templates at runtime.

However, in some cases, it is not optimal, or even worse, not possible to do that. For example, browser extensions do not allow javascript code to create a new function (using the new Function(...) syntax).

Therefore, in these cases, it is required to compile templates ahead of time. It is possible to do that in Owl, but the tooling is still rough. For now, the process is the following:

1. write your templates in xml files (with a t-name directive to declare the name of the template)
2. Compile them in a templates.js file
3. get the owl.iife.runtime.js file (which is a owl build without the compiler)
4. bundle owl.iife.runtime.js and template.js with your assets (owl needs to be positioned before the templates)

Here is a more detailed explanation on how to compile xml files into a js file:

1. clone the owl repository locally
2. npm install to install all the required tooling
3. npm run build:runtime to build the owl.iife.runtime.js file
4. npm run build:compiler to build the template compiler
5. npm run compile_templates -- path/to/your/templates will scan your target folder, find all xml files, get all templates, compile them, and generate a templates.js file.