docusaurus/lib/server/translate-plugin.js

/**
 * Copyright (c) 2017-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

/* replaces translate tags with calls to translate function */

module.exports = function translatePlugin(babel) {
  const {types: t} = babel;

  return {
    visitor: {
      JSXElement(path) {
        if (path.node.openingElement.name.name !== 'translate') {
          return;
        }
        /* assume translate element only has one child which is the text */
        const text = path.node.children[0].value.trim().replace(/\s+/g, ' ');
        let description = 'no description given';
        const attributes = path.node.openingElement.attributes;
        for (let i = 0; i < attributes.length; i++) {
          if (attributes[i].name.name === 'desc') {
            description = attributes[i].value.value;
          }
        }
        /* use an expression container if inside a JSXElement */
        if (path.findParent(() => true).node.type === 'JSXElement') {
          path.replaceWith(
            t.jSXExpressionContainer(
              t.callExpression(t.identifier('translate'), [
                t.stringLiteral(text + '|' + description),
              ])
            )
          );
        } else {
          path.replaceWith(
            t.callExpression(t.identifier('translate'), [
              t.stringLiteral(text + '|' + description),
            ])
          );
        }
      },
    },
  };
};