html-webpack-plugin/lib/loader.js

50 lines
1.8 KiB
JavaScript

/* This loader renders the template with underscore if no other loader was found */
'use strict';
var _ = require('lodash');
var loaderUtils = require('loader-utils');
module.exports = function (source) {
if (this.cacheable) {
this.cacheable();
}
var allLoadersButThisOne = this.loaders.filter(loader => {
// Loader API changed from `loader.module` to `loader.normal` in Webpack 2.
return (loader.module || loader.normal) !== module.exports;
});
// This loader shouldn't kick in if there is any other loader
if (allLoadersButThisOne.length > 0) {
return source;
}
// Skip .js files
if (/\.js$/.test(this.request)) {
return source;
}
// The following part renders the tempalte with lodash as aminimalistic loader
//
// Get templating options
var options = loaderUtils.parseQuery(this.query);
// Webpack 2 does not allow with() statements, which lodash templates use to unwrap
// the parameters passed to the compiled template inside the scope. We therefore
// need to unwrap them ourselves here. This is essentially what lodash does internally
// To tell lodash it should not use with we set a variable
var template = _.template(source, _.defaults(options, { variable: 'data' }));
// All templateVariables which should be available
// @see HtmlWebpackPlugin.prototype.executeTemplate
var templateVariables = [
'compilation',
'webpack',
'webpackConfig',
'htmlWebpackPlugin'
];
return `var _ = require(${loaderUtils.stringifyRequest(this, require.resolve('lodash'))});
module.exports = function (templateParams) {
${// Declare the template variables in the outer scope of the
// lodash template to unwrap them
templateVariables.map(variableName => `var ${variableName} = templateParams.${variableName}`).join(';')
};
return (${template.source})();
}`;
};