tab-loader.js

"use strict";

const fs = require('fs-extra');
const path = require('path');

/**
 * The backend method that is called during the patternlab-pattern-write-end event.
 * Responsible for looking for a companion filetype file alongside a pattern file and outputting it if found.
 * @param patternlab - the global data store
 * @param pattern - the pattern object being iterated over
 */
function findTab(patternlab, pattern) {

  //read the filetypes from the configuration
  const fileTypes = patternlab.config.plugins['plugin-node-tab'].options.tabsToAdd;

  //exit if either of these two parameters are missing
  if (!patternlab) {
    console.error('plugin-node-tab: patternlab object not provided to findTab');
    process.exit(1);
  }

  if (!pattern) {
    console.error('plugin-node-tab: pattern object not provided to findTab');
    process.exit(1);
  }

  //derive the custom filetype paths from the pattern relPath
  var customFileTypePath = path.join(patternlab.config.paths.source.patterns, pattern.relPath);

  //loop through all configured types
  for (let i = 0; i < fileTypes.length; i++) {
    const fileType = fileTypes[i].toLowerCase();

    customFileTypePath = customFileTypePath.substr(0, customFileTypePath.lastIndexOf(".")) + '.' + fileType;
    var customFileTypeOutputPath = patternlab.config.paths.public.patterns + pattern.getPatternLink(patternlab, 'custom', '.' + fileType);

    //look for a custom filetype for this template
    try {
      var tabFileName = path.resolve(customFileTypePath);
      var tabFileNameStats = null;
      try {
        var _stats = fs.statSync(tabFileName);
        _stats && (tabFileNameStats = _stats);
      } catch (err) {
        //not a file - move on quietly
      }
      if (tabFileNameStats && tabFileNameStats.isFile()) {
        if (patternlab.config.debug) {
          console.log('plugin-node-tab: copied pattern-specific custom file for ' + pattern.patternPartial);
        }

        //copy the file to our output target if found
        fs.copySync(tabFileName, customFileTypeOutputPath);
      } else {

        //otherwise write nothing to the same location - this prevents GET errors on the tab.
        fs.outputFileSync(customFileTypeOutputPath, '');
      }
    }
    catch (err) {
      console.log('plugin-node-tab:There was an error parsing sibling JSON for ' + pattern.relPath);
      console.log(err);
    }
  }
}

module.exports = findTab;