thunder.js

/*!
 * thunder
 * Copyright(c) 2012 dreamerslab <ben@dreamerslab.com>
 * MIT Licensed
 *
 * @fileoverview
 * A lightning fast JavaScript template engine.
 */

;( function ( root ){
  var cache = {};

  // split `escape` into another obj speeds up the `no escape` parsing
  var escape = {

    rules : {
      '&' : '&amp;',
      '<' : '&lt;',
      '>' : '&gt;',
      '"' : '&quot;'
    },

    fn : function ( input ){
      return typeof( input ) != 'string' ?
        input : input.replace( /[&<>"]/g, function ( match ){
          return escape.rules[ match ];
        });
    }
  };

  var thunder = {

    // for client-side
    html_to_text : function ( input ){
      return input.
        replace( /\"/g, '\\\"' ).
        replace( /\n/g, '\\n\\\n' );
    },

    compiled_text : function ( input, options ){
      var arr = ( options && options.compress === true ?
        // compress
        input.replace( /\n\r\t|\s+/g, ' ' ) :
        // chage the new line to unix version
        input.replace( /\n\r|\r/g, '\n' )).
          split( '<?' ).join( '?>\x1b' ).split( '?>' );

      var str = '';
      var i   = 0;
      var j   = arr.length;
      var tmp;

      // string concat is faster than array `push`
      for(; i < j; i++ ){
        tmp = arr[ i ];
        str += tmp.charAt( 0 ) != '\x1b' ?
          // `\t` (tab) is ok, we need to handle with `\n` (line feed)
          "__t__+='" + tmp.replace( /\'|\\/g, '\\$&' ).replace( /\n/g, '\\n\\\n' ) + "'" :
            ( tmp.charAt( 1 ) == '=' ?
              ';__t__+=' + tmp.substr( 2 ) + ';' :
              ( tmp.charAt( 1 ) == '-' ?
                ';__t__+=e(' + tmp.substr( 2 ) + ");" :
                ';' + tmp.substr( 1 )));
      }

      // `replace` is faster than `split` -> `join`
      return ( 'var __t__="";' + str + ';return __t__;' ).
        replace( /__t__\+\=\'\'\;/g, '' ).
        replace( /var __t__\=\"\"\;__t__\+\=/g, 'var __t__=' );
    },

    compile : function ( input, options ){
      var str = this.compiled_text( input, options );
      var fn;

      try{
        // must save this new Function to fn,
        // do not just invoke in the return function, it's slow.
        // ex. return new Function( 'it', 'e', str )( locals, escape.fn ); <-- never do that
        fn = new Function( 'it', 'e', str );
      }catch( err ){
        console.log( '[thunder] Having trouble with creating a template function: \n' + str );
        throw err;
      }

      return function ( locals ){
        return fn( locals, escape.fn );
      };
    },

    cached : function ( input, options ){
      if( !cache[ input ]){
        cache[ input ] = this.compile( input, options );
      }

      return cache[ input ];
    },

    render : function ( input, locals, options ){
      var method = options && options.cached === true ?
        'cached' : 'compile';

      return this[ method ]( input, options )( locals );
    }
  };

  // browser support
  if( typeof exports === 'undefined' ) return root.call( thunder );

  // requirejs
  if( typeof define !== 'undefined' ){
    return define( function ( require, exports, module ){
      module.exports = thunder;
    });
  }

/**
 * @public
 */
  thunder.version = JSON.parse(
    require( 'fs' ).readFileSync( __dirname + '/../package.json', 'utf8' )
  ).version;

/**
 * Exports module.
 */
  module.exports = thunder;
})( this );