CodeIgniter Tips

Since I'm a cheap miser (jk - I'm just haven't made enough cool apps to justify my getting a server) I use the free option on PHPFog to host apps. PHPFog is just like Heroku except with PHP. You use git to push your content to the cloud (no FTP uploads for websites) and they provide easy server setup for your PHP app.

The nice thing about uploading using git is that in the meantime, you can test your application locally. There are, however, a few things to set up so that you can work locally. The most minor details lie in the config files where you'll have to make sure of some things like:

in config.php you really don't want to be setting a base_url since you want your app to work both locally and on PHPFog's servers.

database.php - set it up using the database configuration options from the PHPFog website including the hostname. Now here is one tricky part - I have a hostname of db01-share on PHPFog but I don't want to change that to localhost (cause then when I push the code to the servers, things will not work). So what I did was edit the hosts file on Windows 7 to redirect to 127.0.0.1 (localhost) and this worked fine, but not on Mac Lion. Dammit.

Don't forget to create the user from PHPFog in your own database. This brings up the point of whether phpMyAdmin's sync servers function can be used...but I'm a budding web developer and I have never used that feature before. I always like going the DIY route anyway.

So I ran into some stupid bugs and not-so-stupid bugs so I quickly wanted to share this with anyone who might see this, and to review what I learned today also.

Let me describe the page I'm building right now -

I'm building a website for an artist and that website has a backend where you can edit/upload pictures and their titles. For the edit section I have a grid of pictures that you can select in order to load their information into form elements. I want to do this with AJAX (using jQuery) so I make it send an AJAX request (probably not the right terminology but hopefully you know what I mean) to a CodeIgniter controller.

Now the first problem was my lack of understanding/realizing that there is going to be a problem sending data to/from CodeIgniter and jQuery. So basically there are helper functions for PHP and Javascript that facilitate with translating string<->JSON object. This is due to the fact that PHP can only pass a string as data to Javascript. We then convert that string-form JSON into a JSON object in Javascript by using jQuery's jQuery.parseJSON(). http://api.jquery.com/jQuery.parseJSON/

The code is pretty simple so I think I'll just post the code and it should be pretty clear how to do this. If not - definitely leave a comment and I'll reply ASAP if anyone actually needs help with this :)

http://snipt.net/ehdeelee/ajax-call-from-javascript

http://snipt.net/ehdeelee/ajax-receiver-from-codeigniter

Something that I feel is useful throughout CodeIgniter is the different between array syntax such as

$data['title']

in order to later pass it into a view

$this->load->view('viewname',$data);

and object syntax for things like activerecords with the database class such as

$query = $this->db->get('tablename')->result();

and then if your table had a field of

'name'

you'd reference it like

echo $query->name;

I'm new to CodeIgniter and I am learning about the cart class right now. It is crazy how there is a class like this built into CodeIgniter! Past the initial amazement, I suppose Django and Ruby on Rails are just as crazy - if there isn't a cart class built-in, there are probably dozens of classes that other programmers have created for facilitating coding like this.

It is so simple to use!

http://codeigniter.com/user_guide/libraries/cart.html

So a useful thing that I've recently discovered is writing a short Javascript snippet of code to reload the page. This is useful when coding because you can just save the changes of your file and have the website reload by itself - no need to switch to your browser and manually reload.

Even for CSS where you can use developer tools for Safari/Chrome/Firefox to add CSS styles and see their effect immediately, it is still useful to go with this Javascript snippet method because you're additionally saving all changes. With the developer tools you would have to copy and paste the code back in your file (although there are probably ways to save directly to your file).

So without further delay:

<script>

window.setTimeout("window.location.reload()", 2500);

Create a .htaccess file in your root CodeIgniter project folder (place where the "application", "system" folders are).

Add this into the file:

RewriteEngine On RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^(.*)$ /ci_fileupload/index.php/$1 [L]

Showing hidden files on Mac:

http://www.codeigniter.com/user_guide

(memorize it! - worth memorizing because it's a great guide you will constantly go back to check)

And what I do is keep an empty CodeIgniter source code folder in my home directory and every time I create a new project, just "cp -r" it. If you're working without internet, the local version of the user guide URL would be:

http://linux.justinhartman.com/Setting_up_a_LAMP_Server#Creating_users_to_use_MySQL_and_Changing_Root_Password

mysql is located in /opt/lampp/bin/mysql so instead of mysql -u root just do /opt/lampp/bin/mysql -u root

You also need to go to /opt/lampp/phpmyadmin/config.inc.php and change the password in there too.

To send an email (say from a Gmail) through CodeIgniter, you first need to create a file in the application/config/ called email.php.

In the picture below, the first line makes sure that this file cannot be accessed by anybody else.

  Then, in your controller, you will want this code (pretty self-explanatory imho):

One thing I will mention is that instead of doing the $this->load->library('email') you could autoload that by modifying the autoload.php in the config folder.

I lied. In one of my earliest posts I said I wouldn't be talking about the MVC concept at all (because I was unqualified to do so) but now I feel like giving it a shot anyway.

MVC stands for Model View Controller. Model is for storing data, View is for displaying HTML, and Controller is for the logic of your web app. Basically, Controller is the boss and both Model and View report to him - and he can do whatever he wants with them.

With CodeIgniter, the MVC "architectural pattern" (stole that one from Wikipedia) is very loosely enforced. For example, if you have a controller called site then that controller is called when the url http://www.yoursite.com/index.php/site gets loaded. From there you would load a model to retrieve data from a database and then load the view with the data that you got from the model.

The config folder is located at ci/application/config. (where ci is the CodeIgniter code you downloaded)

The files that I have come into contact so far are:

autoload.php

config.php

database.php

routes.php

routes.php I have never really modified anything inside of it yet - I just know that "routes" in the web_development/web_framework world is for describing what page gets loaded when a url like http://yoursite.com/whichPage gets called. Read up on URI's.

autoload.php is for autoloading libraries such as "database" or "url" instead of having to do something like "$this->load->library('database');" inside every controller that you use the library for.

config.php has some general configuration settings like the base url for your website (useful if you're working locally) and this is where you change the option to get rid of the annoying "index.php" in your url too.

As with all my other posts early on, please take what I say with a grain of salt because I am still new to all this stuff and learning.

In phpMyAdmin basically you will encounter the terms: database, table, and row. How I see it is that each project should have its own database, each "function" (thing you're trying to accomplish) should require its own table inside the appropriate database, and rows are basically entries in the database.

To clarify a bit, something like login credentials or like storing blog posts would each have its own table. The field names for each of the tables (relatively) would be something like username and password for login credentials and title, author, and contents for something like storing blog posts.

For all tables I've run into so far, there was always an "id" field that is set to type "int", set as "primary key", and then set to "autoincrement (AI)".