joytpl/index.js

joy - js template engine with short syntax and modern features

const fs = require('fs');
const ASTY = require('asty');
const prettier = require('prettier');
const pegUtil = require('pegjs-util');
const parser = require('./lib/generated/parser');
const processor = require('./lib/processor/processor');
const defaults = require('./lib/defaults');
const requireFromString = require('require-from-string');

const joy = {
    build(input, options, cb) {
        if (cb === undefined && typeof options === 'function') {
            cb = options;
            options = {};
        }

        options = Object.assign({}, defaults, options);

        this.parse(input, (err, ast) => {
            if (err) {
                console.error(err);
            }
            else {
                // console.log(ast.dump().replace(/\n$/, ""));
                this.process(ast, options, (err, result) => {
                    if (err) {
                        cb(err);
                    }
                    else {
                        cb(null, result);
                    }
                });
            }
        });
    },
    parse(input, cb) {
        const asty = new ASTY();
        const result = pegUtil.parse(parser, input, {
            startRule: 'start',
            makeAST: function (line, column, offset, args) {
                return asty.create.apply(asty, args).pos(line, column, offset);
            }
        });

        cb(result.error, result.ast);
    },
    process(parsed, options, cb) {
        try {
            let res = processor(parsed, options);

            if (options.beautify) {
                res.content = prettier.format(res.content, {parser: 'babel'});
            }

            cb(null, res);
        }
        catch(err) {
            cb(err);
        }
    }
};

// Express support

const expressOptions = {
    modules: 'commonjs',
    validators: {
        Import: [
            () => {
                throw Error('Import statement not allowed in express views, plz use precompilation if u need it');
            }
        ]
    }
};

// to avoid binding
joy.express = joy.__express = (filePath, data, cb) => {
    fs.readFile(filePath, (err, content) => {
        if (err) {
            return cb(err);
        }

        joy.build(content.toString(), expressOptions, (err, result) => {
            if (err) {
                return cb(err);
            }

            const tpl = requireFromString(result.content);

            cb(null, tpl(data));
        });
    });
};

module.exports = joy;