The majority of HTML template languages sucks. Some exceptions are rust’s html crate, C#’s razor and an handful of others. All the others are glorified string formatters.
But what makes a good HTML templatating language? First, a good HTML templating language should only produces valid html. Similarly, it should only accepted valid data input. As any good software, a good templating language should be composable; it should be possible to breakdown a large template into multiple small templates. As this problem is not specific to a single language, it would be nice if the solution would be able to scale in multiple different programming languages.
| Difficulty | Very high |
| Programming language | Web Assembly |
| Project type | Create a new library |
First Technical Ideas
| Name | Definition |
|---|---|
| Template | The main document of a templating language |
| Input Data Format | The data format a template requires to be able to be viewed as HTML |
| Compiling | Process that takes a template as input and returns a function that can generate an HTML from data input (Renderer) |
| Rendering | Process of taking a compiled template and input data to generate valid HTML |
| Host Programming Language | The programming language used by the programmer |
What is an html templating language?
The user experience for a template language is something as below:
const template = templates.load('my-template.tmpl')
return template.render({user, book})
which can be summarize as a function from a TemplateInput to HTML. Consequently,
the programmer expects 2 things from a “template”; first the template must be able
to provide the input data type, second the template must be able to render html.
What should be the output of compiling templates
When a user renders templates, the user must provides 2 things; first the template content, second template names. The compiler than produces a set input data format and renderers. The input data formats should be valid types in the host programming language, the renderers should be functions that takes an input data format and return a valid html.
Crazy path
Step One - Defining the template
Each template has 2 sections, one defining the input data format as a
Protobuf spec and the template itself. For now, we can
minimaze the template to the most trivial renderer; the hello world
renderer (a template that always returns <h1>hello world</h1>).
Step Two - Extracting the protobuf input data formats
The first thing the compiler should be able to do is to output the input data formats in a standalone protobuf file.
Step Three - Continue…
Hold tight, and create a bunch of scripts that generates a rust program that can compile into wasm function renderer. That might not be trivial. I assume nix can help lock rust and cargo version in sync. Good luck.