node.js hot reload of js files. (it is not restart, more like erlang)

hotreload.path

hotreload.watch(script, reload_callback)

watch script file, onchange load the script file and call callback

script is string

reload_callback(newmodule) is a function, it has an argument - the loaded module object.

hotreload.watch(watchpath, script , reload_callback)

watch one file and load another.

watchpath can be a string or an array script is string

hotreload.watchrel(script, reload_callback)

watch script file relative to @hotreload.path@

hotreload.watchrel(watchpath, script , reload_callback)

example:

server.js:

var http = require('http');
var hotreload= require('node-hot-reload');
    hotreload.path=__dirname;

//1st require the module normaly

var mymodule= require('./mymodule_example'); 


//2nd watch it and reload it dinamicaly

// explained example:

hotreload.watchrel('mymodule_example.js', function (newmodule){

   /* you can put here staff to make your module
      look like it was initialized well. */

   newmodule.name=mymodule.name; // take care to copy previous data

   //mymodule.init(); // init the module before if possible,
                      // it will save error time.
   // option 1
   // replace reference - probably the best way
   // but you must update all references you have 
   // replace reference - probably the best way
   // but you must update all references you have 

   //mymodule=newmodule;
   //myothermodulereference=newmodule;


   // option 2
   // copy properties from new module to old module
   // as a solution to not having to update
   // references to module object
   hotreload.copy(mymodule,newmodule);

   // option 3
   //   manually patch the old object with parts of the new object.

   // initialization or more initialization after switching to the new module
   // mymodule.init();
   // better don't do it, you may get errors,
   // because of not well-initialized module.

});

// simple example1:
//hotreload.watchrel('mymodule_example.js',
//  function (newmodule){ mymodule=newmodule; } );
  
// simple example2:
//hotreload.watchrel('mymodule_example.js',
//  function (newmodule){ hotreload.copy(mymodule,newmodule); } );

// idea: add loader function to automate reloading of modules:
//  

mymodule.name="Shimon";

http.createServer(function (request, response) {

  try
  {
   response.writeHead(200, {'Content-Type': 'text/plain'});
   response.end(mymodule.time() + '\n');
  }
  catch(err)
  {
   response.end(err.stack);
   console.log(err.stack);
  }

  //to do, main module reloadable instead of above you might use: 
  //mymodule.handlerequest(req,res); 
   
}).listen(8124);

console.log('Server running at http://127.0.0.1:8124/');

mymodule_example.js:

console.log('mymodule loaded');
exports.name='test';
exports.date=(new Date).toString();
exports.time=function ()
{
                      //  edit the number to see it working
 return  " test number 17 name: "+exports.name+" , loaded at: "+exports.date.toString();
}
exports.filename=__filename;