phs (Parameterized HTML Schemas)

This is a library that can be used to describe and validate chunks of HTML. It is inspired by RELAX NG, but with a few very different goals. phs schemas are designed to:

• Accept placeholders for parameters, so that schemas can also be used to serialize and deserialize chunks of data to/from HTML. Not implemented yet.
• Be more concise and easier to author/read/understand than the full RELAX NG specification.
• Resemble the HTML they describe and be easily expressible in JSX notation.

Note: Currently this library contains the bare minimum to be at all useful.

How to use

Currently it's recommended to use JSX with the transform-jsx-flexible Babel plugin. If you're using React, for example, this allows you to continue using React elements along with phs schemas within the same file.

Configure the plugin as follows in your .babelrc:

"plugins": [
    ...
    [ "./lib/babel-plugin-transform-jsx-flexible", {
        tags: {
            Schema: 'createSchemaElement',
        }
    } ],
    ...
]

In your JSX code files:

import { createSchemaElement, Schema, Element } from 'phs';

const schema = (
    <Schema>
        <Element name="p" />
    </Schema>
);

const fragment = /* DOM fragment or similar object returned by a parser */;

const result = schema.validateFragment( fragment );

console.log( result ); // either `true` or an `Error`

There are also a couple of validation functions other than validateFragment:

• validateNodes( arrayOfNodes )
• validateNode( singleNode )

Schema elements

<Element name="tagName">

Matches a single HTML element with the tag name tagName. tagName can also be a string like 'p|span' to provide a choice between multiple tag names.

There is also a shorthand for <Element> that is designed to more closely resemble the HTML it describes. These two constructions are equivalent:

const schema1 = (
    <Schema>
        <Element name="div" />;
    </Schema>
);

const schema2 = (
    <Schema>
        <div />
    </Schema>
);