path_set.js

/**
 * Path Set
 * A libary for storing and generating paths for an application based on params
 * @author Tal Atlas <[email protected]>
 *
 *   ps = new PathSet({
 *     root: '/',
 *     album: '/albums/:id(.:format)',
 *     album_pictures: '/albums/:album_id/pictures(/:id)(.:format)'
 *   });
 *
 *  ps.album_pictures_path({album_id: 123})                 // => /albums/123/pictures
 *  ps.album_pictures_path({album_id: 123, foo: 'bar'})     // => /albums/123/pictures?foo=bar
 *  ps.album_pictures_path({album_id: 123, format: 'json'}) // => /albums/123/pictures.json
 *  ps.album_pictures_path({album_id: 123, id: 345})        // => /albums/123/pictures/345
 */

(function() {
  window.PathSet = function PathSet(paths,opts) {
    var url, self = this, pathName;

    this.paths = paths;
    opts || (opts = {});
    this.defaults = opts.defaults || {};

    function buildFunc(pathName) {
      self[pathName+'_path'] = function(params) {
        var defaults = self.defaults[pathName], param;
        if (defaults) {
          for (param in defaults) {
            if (params[param] === undefined && defaults[param] !== undefined) {
              params[param] = defaults[param];
            }
          }
        }
        return PathSet.matchPath(paths[pathName],params);
      }
    }

    for (pathName in paths) {
      buildFunc(pathName);
    }
  };

  var PATH_REG = /(.+)(?:\((?:[^:)]*:\w[a-z0-9:\/-_(.]*)\))/i, r20 = /%20/g;
  PathSet.matchPath = function matchPath(path,params,domain) {
    var re = /:(\w+)/g, match, pathMatch, value, url;

    url = path;

    params || (params = {});

    // Match all values in url and replace them with values from the form
    while (match = re.exec(path)) {
      value = params[match[1]];

      if (value) {
        url = url.replace(match[0],value);
        delete params[match[1]];
      }
    }

    // Remove optional portions of the path
    while (match = url.match(PATH_REG)) {
      url = url.replace(PATH_REG,'$1');
    }
    url = url.replace(/[()]/g,'');

    // Append all additional params to the query string
    var additional_params = []
    if (jQuery && jQuery.param) {
      additional_params.push(jQuery.param(params));
    } else {
      for (var param in params) {
        additional_params.push((encodeURIComponent(param)+'='+encodeURIComponent(params[param])).replace(r20,'+'));
      }
    }

    if (additional_params.length) {
      if (url.match(/\?/)) url = url + '&';
      else url = url+'?';
      url = url + additional_params.join('&');
    }

    if (domain) {
      url = domain + url;
    }

    return url;
  };
}).call(this);