CSE2410 Fall 2014 Bounce

// module search paths

node.includes = ["."];

// This is useful for dealing with raw encodings.

Array.prototype.encodeUtf8 = function () {

  return String.fromCharCode.apply(String, this);

}

node.path = new function () {

  this.join = function () {

    var joined = "";

    for (var i = 0; i < arguments.length; i++) {

      var part = arguments[i].toString();

      if (i === 0) {

        part = part.replace(/\/*$/, "/");

      } else if (i === arguments.length - 1) {

        part = part.replace(/^\/*/, "");

      } else {

        part = part.replace(/^\/*/, "")

               .replace(/\/*$/, "/");

      }

      joined += part;

    }

    return joined;

  };

  this.dirname = function (path) {

    if (path.charAt(0) !== "/") 

      path = "./" + path;

    var parts = path.split("/");

    return parts.slice(0, parts.length-1).join("/");

  };

};

// Namespace for module loading functionality

(function () {

  function findScript(base_directory, name, callback) {

    // in the future this function will be more complicated

    if (name.charAt(0) == "/")

      throw "absolute module paths are not yet supported.";

    var filename = node.path.join(base_directory, name) + ".js";

    File.exists(filename, function (status) {

      callback(status ? filename : null);

    });

  }

  // Constructor for submodule.

  // "name" is like a path but without .js. e.g. "database/mysql"

  // "target" is an object into which the submodule will be loaded.

  function Sub (name, target) {

    this.name = name;

    this.target = target;

    this.load = function (base_directory, callback) {

      //node.debug("sub.load from <" + base_directory + ">  " + this.toString());

      findScript(base_directory, name, function (filename) {

        if (filename === null) {

          stderr.puts("Cannot find a script matching: " + name);

          process.exit(1);

        }

        loadScript(filename, target, callback);

      });

    };

    this.toString = function () {

      return "[sub name=" + name + " target=" + target.toString() + "]";

    }

  }

  function Scaffold (source, filename, module) {

    // wrap the source in a strange function 

    var source = "function (__filename) {" 

               + "  var onLoad;"

               + "  var exports = this;"

               + "  var require = this.__require;"

               + "  var include = this.__include;"

               +    source 

               + "  this.__onLoad = onLoad;"

               + "};"

               ;

    // returns the function       

    var compiled = node.compile(source, filename);

    if (module.__onLoad) {

      //node.debug("<"+ filename+"> has onload! this is bad");

    }

    module.__subs = [];

    module.__require = function (name) {

      var target = {};

      module.__subs.push(new Sub(name, target));

      return target;

    }

    module.__include = function (name) {

      module.__subs.push(new Sub(name, module));

    }

    // execute the script of interest

    compiled.apply(module, [filename]);

    // The module still needs to have its submodules loaded.

    this.filename = filename;

    this.module  = module;

    this.subs    = module.__subs;

    this.onLoad = module.__onLoad;

    // remove these references so they don't get exported.

    delete module.__subs;

    delete module.__onLoad;

    delete module.__require;

    delete module.__include;

  }

  function loadScript (filename, target, callback) {

    File.cat(filename, function (status, content) {

      if (status != 0) {

        stderr.puts("Error reading " + filename + ": " + File.strerror(status));

        process.exit(1);

      }

      var scaffold = new Scaffold(content, filename, target);

      //node.debug("after scaffold <" + filename + ">");

      function finish() {

        //node.debug("finish 1 load <" + filename + ">");

        if (scaffold.onLoad instanceof Function) {

          //node.debug("calling onLoad for <" + filename + ">"); 

          scaffold.onLoad(); 

        }

        //node.debug("finish 2 load <" + filename + ">");

        if (callback instanceof Function)

          callback();

      }

      // Each time require() or include() was called inside the script 

      // a key/value was added to scaffold.__subs.

      // Now we loop though each one and recursively load each.

      if (scaffold.subs.length == 0) {

        finish(); 

      } else {

        var ncomplete = 0;

        for (var i = 0; i < scaffold.subs.length; i++) {

          var sub = scaffold.subs[i];

          sub.load(node.path.dirname(filename), function () {

            ncomplete += 1;

            //node.debug("<" + filename + "> ncomplete = " + ncomplete.toString() + " scaffold.subs.length = " + scaffold.subs.length.toString());

            if (ncomplete === scaffold.subs.length)

              finish();

          });

        }

      }

    });

  }

  loadScript(ARGV[1], this);

})();