grunt-ez-frontend/lib/preprocess.js

Easily configure Grunt to concatenate, minimize js files, parse less files, concatenate them with other css files and minimize them using csso and autoprefix

module.exports = function ( grunt ) {
  'use strict';
  var fs = require( 'fs' ),
    path = require( 'path' ),
    lib = require( '../lib/lib' );

  var log = require( './log' )( grunt );

  var format = lib.format,
    logVerbose = log.logVerbose,
    trim = lib.trim,
    extend = lib.extend,
    isNull = lib.isNull,
    verbose = grunt.verbose,
    file = grunt.file;


  // Please see the grunt documentation for more information regarding task and
  // helper creation: https://github.com/cowboy/grunt/blob/master/docs/toc.md

  // ==========================================================================
  // TASKS
  // ==========================================================================


  //var commandTokenRegex = /\[\s*(\w*)\s*([\w="'-.\/\s]*)\s*\]/gi;


  function doParse( value ) {
    try {
      return JSON.parse( value );
    } catch (ex) {
      verbose.writeln( 'The value was not parsed properly. Returning it as text, ' + ex.message + ', ' + value );
      return value;
    }
  }

  function parseAttributes( c ) {
    var obj = {};
    var parts = trim( c ).split( ' ' );
    for (var i = 0, len = parts.length; i < len; i++) {
      var subParts = trim( parts[ i ] ).split( '=' );
      var twoParts = subParts.length > 1;
      var value = twoParts ? trim( subParts[ 1 ] ).replace( /^"|"$|^'|'$/gi, '' ) : '';

      if ( subParts.length > 1 && value.length > 0 ) {
        obj[ subParts[ 0 ] ] = doParse( value );
      }
    }
    return obj;
  }

  function processCommand( a, b, c, dirOfFile ) {
    verbose.writeln( format( 'Token found ==> {0}, {1}, {2}, {3}', a, b, c, dirOfFile ) );
    if ( b === 'INCLUDE' ) {
      verbose.writeln( 'Executing INCLUDE command' );
      var options = {
        removeLineBreaks: true,
        escapeQuotes: true
      };
      extend( options, parseAttributes( c ) );
      verbose.writeln( 'INCLUDE ATTRS \n', JSON.stringify( options, null, 2 ) );

      var pathOfFile = path.normalize( path.join( dirOfFile, options.src ) );
      verbose.writeln( 'path of file to read ' + pathOfFile );

      var content = '';

      try {
        content = file.read( pathOfFile );
        if ( options.removeLineBreaks ) {
          content = content.replace( /(\r\n|\n|\r)/gm, '' );
        }
        if ( options.escapeQuotes ) {
          content = content.replace( /'|"/gi, '\\$&' );
        }
      } catch (ex) {
        grunt.log.error( 'Unable to read "' + pathOfFile );
      }

      return trim( content );
    }
    return a;
  }

  function findTokens( src, dirOfFile, commandTokenRegex ) {
    src = src.replace( commandTokenRegex, function ( a, b, c ) {
      return processCommand( a, b, c, dirOfFile );
    } );
    return src;
  }



  function doReplace( src, regex, replacement, dirOfFile, filePath ) {
    if ( typeof replacement === 'string' ) {
      return src.replace( regex, replacement );
    }
    if ( typeof replacement === 'function' ) {
      var fileProps = {
        path: filePath,
        dir: dirOfFile
      };
      return src.replace( regex, function () {
        var args = Array.prototype.slice.call( arguments );
        args.unshift( fileProps );
        return replacement.apply( null, args );
      } );
    }
    return src;
  }

  function executeReplacements( src, replacements, dirOfFile, filePath ) {

    for (var i = 0, len = replacements.length; i < len; i++) {
      var current = replacements[ i ],
        regex = current.replace,
        replacement = current.using;

      if ( isNull( regex ) ) {
        continue;
      }
      logVerbose( 'replacing:-----', regex, replacement );
      src = doReplace( src, regex, replacement, dirOfFile, filePath );
    }
    return src;
  }

  // Concat source files and/or directives.
  return function ( files, options ) {
    return files ? files.map( function ( filepath ) {

      var data = grunt.file.read( filepath ),
        dirOfFile = path.dirname( filepath );

      data = findTokens( data, dirOfFile, options.tokenRegex );
      data = executeReplacements( data, options.replacements || [], dirOfFile, filepath );

      //console.log(options.processContent.toString());
      options.processContent && (data = options.processContent( data, filepath ));

      return data;
    } ).join( grunt.util.normalizelf( options.separator ) ) : '';
  };
};