twitter-mustache-loader.js

var Hogan = require('./twitter-hogan');
var renderOptions = { asString: true, sectionTags: [{ o: '_i', c: 'i' }] };
var translateMustache = require('./translate-mustache');

function extractPartials(tmpl) {
  // need eval to pull the partials out of the Hogan-generated string
  /* eslint-disable no-eval */
  var hoganParams = eval(`(${tmpl})`);
  /* eslint-enable no-eval */
  var partialNames = [];
  for (var key in hoganParams.partials) {
    partialNames.push(hoganParams.partials[key].name);
  }
  return partialNames;
}

// templates/client is specified in resolve.config
function partialPath(name) {
  return `${name}.mustache`;
}

function templateModuleWithoutPartials(tmpl) {
  return `module.exports = new Hogan.Template(${tmpl});`;
}

function templateModuleWithPartials(tmpl, partialNames) {
  var dependencies = partialNames.map((name) =>
    `'${name}': require('${partialPath(name)}')`
  ).join(',\n');

  // Hogan is injected by ProvidePlugin
  return `
    var mergeTemplates = require('app/utils/merge_templates');
    var dependencies = {
      ${dependencies}
    };
    var defaultPartials = mergeTemplates(dependencies);
    var template = new Hogan.Template(${tmpl});

    function render(context, partials, indent) {
      partials = partials || {};

      for (var key in defaultPartials) {
        if (!partials[key]) {
          partials[key] = defaultPartials[key];
        }
      }

      return template.render(context, partials, indent);
    };

    module.exports = {
      template: template,
      partials: defaultPartials,
      render: render
    }
  `;
}

module.exports = function(source) {
  var phrases = this.options.phrases || {};
  this.cacheable();

  var translatedSource = translateMustache(source, phrases);
  var tmpl = Hogan.compile(translatedSource, renderOptions);
  var partialNames = extractPartials(tmpl);

  if (!partialNames.length) {
    return templateModuleWithoutPartials(tmpl);
  } else {
    return templateModuleWithPartials(tmpl, partialNames);
  }
};