Ember.js utility to generate a controller computed property that compares a string to a part of the currentPath. Used to create boolean properties that update on based on the state of the application.

path_compare.js

Ember.PathCompare = {
  comparePartsToString: function(parts, compare, index) {
    var str, first;
    if (index === undefined) {
      index = parts.length - 1;
    } else {
      if (index < 0) {
        index = (parts.length - 1) - (index * -1);
      }
    }
    str = parts[index];
    first = compare[0];
    if (first === '!') {
      return str !== compare.slice(1);
    } else {
      return str === compare;
    }
  },

  comparePartsToArray: function(parts, arr) {
    var str, first, index, compare = arr[0];
    if (arr[1] !== undefined) {
      index = arr[1];
      if (index < 0) {
        index = (parts.length - 1) - (index * -1);
      }
    } else {
      index = parts.length - 1;
    }
    str = parts[index];
    first = compare[0];
    if (first === '!') {
      return str !== compare.slice(1);
    } else {
      return str === compare;
    }
  },

  compare: function(parts, options) {
    var self = this, val = false;
    if (!parts) return val;
    if (typeof options === 'string') {
      val = self.comparePartsToString(parts, options);
    }
    if ($.isArray(options)) {
      if ($.isArray(options[0])) {
        val = true;
        options.forEach(function(i) {
          if ($.isArray(i)) {
            val = val && self.comparePartsToArray(parts, i);
          }
          if (typeof i === 'string') {
            val = val && self.comparePartsToString(parts, i);
          }
        });
      } else {
        val = self.comparePartsToArray(parts, options);
      }
    }
    return val;
  },

  create: function(options) {
    var self = this, compare = self.compare;
    return function() {
      var bits = this.get('target.router.currentHandlerInfos').reduce(function(memo, item) {
        memo.push(item.name);
        return memo;
      }, []);
      return compare.call(self, bits, options);
    }.property('application.currentPath');
  }
};