jade/lib/runtime.js

/*!
 * Jade - runtime
 * Copyright(c) 2010 TJ Holowaychuk <tj@vision-media.ca>
 * MIT Licensed
 */

/**
 * Render the given attributes object.
 *
 * @param {Object} obj
 * @return {String}
 * @api private
 */

exports.attrs = function attrs(obj){
  var buf = []
    , terse = obj.terse;
  delete obj.terse;
  var keys = Object.keys(obj)
    , len = keys.length;
  if (len) {
    buf.push('');
    for (var i = 0; i < len; ++i) {
      var key = keys[i]
        , val = obj[key];
      if ('boolean' == typeof val || null == val) {
        if (val) {
          terse
            ? buf.push(key)
            : buf.push(key + '="' + key + '"');
        }
      } else if ('class' == key && Array.isArray(val)) {
        buf.push(key + '="' + escape(val.join(' ')) + '"');
      } else {
        buf.push(key + '="' + escape(val) + '"');
      }
    }
  }
  return buf.join(' ');
};

/**
 * Escape the given string of `html`.
 *
 * @param {String} html
 * @return {String}
 * @api private
 */

exports.escape = function escape(html){
  return String(html)
    .replace(/&(?!\w+;)/g, '&amp;')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;');
};

/**
 * Re-throw the given `err` in context to the
 * `str` of jade, `filename`, and `lineno`.
 *
 * @param {Error} err
 * @param {String} str
 * @param {String} filename
 * @param {String} lineno
 * @api private
 */

exports.rethrow = function rethrow(err, str, filename, lineno){
  var context = 3
    , lines = str.split('\n')
    , start = Math.max(lineno - context, 0)
    , end = Math.min(lines.length, lineno + context); 

  // Error context
  var context = lines.slice(start, end).map(function(line, i){
    var curr = i + start + 1;
    return (curr == lineno ? '  > ' : '    ')
      + curr
      + '| '
      + line;
  }).join('\n');

  // Alter exception message
  err.path = filename;
  err.message = (filename || 'Jade') + ':' + lineno 
    + '\n' + context + '\n\n' + err.message;
  throw err;
};