Archive | November, 2009

symfony APC cache and Memcache session storage

November 30, 2009  by in php, symfony Comments ( 7 )

symfony-memcache

In a previous post I described some of the reasons why you would want to store your session data in an alternate location to temporary files on your server. I explained the setup of database session storage using Doctrine and how this would allow you to take advantage of storing session data in a database. However depending upon your application requirements storing your session data in a database may cause excessive load on you database. You could of course use a separate dedicated database server to store your session data. However there is an alternate setup that will allow you to centralise your session storage ready for horizontal scaling of your hosting e.g. adding additional web servers.

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symfony Doctrine database session storage

November 25, 2009  by in php, symfony Comments ( 20 )

Sessions are normally managed by your server and depending upon how involved you get with the PHP setup you need never know how this data is stored. The default setup for PHP is to store session data in temporary files on the server. So why would we want to change how sessions are handled and what advantage can we gain from any changes we make.

Why use database session management?

Sessions allow you maintain persistence within PHP applications. With every HTTP request a PHP application must re-assign every variable and object needed in your application. Sessions allow you to store data that is required to persist past each HTTP request allowing it to be easily retrieved and used.

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YUI Connect asynchronous file uploads

November 23, 2009  by in JavaScript Comments ( 4 )

I’m sure the problems with multi-part data that I have been working through this morning is very simple but there are a number of forum posts about this, so I will share my findings. When using YUI Connection Manager in conjunction with multi-part form data I have experienced problems creating the asynchronous request and canceling the form submission. Even after setting up the request and callback object and checking the YUI API repeatedly the problem resides elsewhere.

YAHOO.util.Event.addListener(forms, 'submit', this._onFormSubmit, this);

_onFormSubmit: function(e, o)
{
  YAHOO>util.Event.preventDefault(e);
  // Set the form
  YAHOO.util.Connect.setForm(e.currentTarget);
  // Configure the callback object
  callBackObj = {
    success: o._loadRemoteFormSubmissionTemplateComplete,
    failure: o._loadRemoteFormSubmissionTemplateFailed,
    argument: {
      objType: objType, 
      region: regionObj,  
      mode: submitbutton.value}
  }
  // Make the request
  YAHOO.util.Connect.asyncRequest('POST', e.currentTarget.action, callBackObj);
}

With non multi-part forms you can hijack the submit event of the form and create an asynchronous request. However once you try with multi-part data no matter how you set this up and attempt to cancel the form submit action the form will still make an HTTP request in the main window.

The YUI Multi-Part Data Solution

The solution is very simple once you find it but it is easy to overlook! In order to use YUI connect to create an asynchronous request you must remove the ‘submit’ button and replace it with a ‘button’ then assign it an eventListener that will create the asyncRequest.

var alternateButton = document.getElementById('alternateButtonId')
YAHOO.util.Event.addListener(alternateButton, 'click', this._onFormSubmit, this);

_onFormSubmit: function(e, o)
{
  YAHOO.util.Event.preventDefault(e);
  // Set the form
  YAHOO.util.Connect.setForm(e.currentTarget);
  // Configure the callback object
  callBackObj = {
    success: o._loadRemoteFormSubmissionTemplateComplete,
    failure: o._loadRemoteFormSubmissionTemplateFailed,
    argument: {
      objType: objType, 
      region: regionObj,  
      mode: submitbutton.value}
  }
  // Make the request
  YAHOO.util.Connect.asyncRequest('POST', e.currentTarget.action, callBackObj);
}

When trying to use multi-part data YUI Connection Manager will create an iframe in the document that your form will submit the data to. If you try and use the submit handler YUI currently does not change the target value of the submit event.

The YUI examples do all show the use of alternate buttons rather than a standard submit button however it can be easily overlooked. I hope this helps someone!