6CC001 Workshop - week 04
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Your job today is to implement a blog similar to this one:
The different steps are:
- Step 1 - Create and populate database
- Step 2 - Create the index.php file, front controller and registry class
- Step 3 - Handling user request and creating appropriate command
- Step 4 - Accessing the database
- Step 5 - Creating our first view
- Step 6 - Adding messages
- Step 7 - Deleting messages
Let's take it one step at a time... and remember: read and understand the code before pasting it into your text editor!
Step 5 - Creating our first view
All we need now is to pass the data above to a view. Let's create all our views in a "views" sub-folder.
<!-- views/index.php -->
<?require_once("ViewHelper.php");?>
<?ViewHelper::DisplayHeader("Blog index");?>
<h1>Blog index</h1>
<p>You can <a href="index.php?cmd=BlogAddForm">add messages</a> !</p>
<form action="index.php" method="post">
Search: <input name="search">
<input type="submit" value="Search!">
</form>
<?
foreach($data as $message)
echo("<div class=\"message\">
<h2>{$message['title']}</h2>
<p>{$message['message']}</p>
<a href=\"index.php?cmd=BlogDelete&id={$message['id']}\">Delete this message</a>
</div>");
?>
<?ViewHelper::DisplayFooter();?>
The code itself it pretty simple. It loops through the data array using a foreach statement.
Note that instead of duplication the <HEAD> section in all our views, we have decided to move it to a helper function. All our views can then include the helper file and call the DisplayHeader and DisplayFooter function:
// views/ViewHelper.php
//############################################################################
// ViewHelper
//############################################################################
class ViewHelper
{
//############################################################################
// Displays HTML Header
//############################################################################
static function DisplayHeader($pageTitle = "")
{
echo("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
echo("<html>");
echo(" <head>");
echo(" <title>{$pageTitle}</title>");
echo(" <link type=\"text/css\" href=\"views/style.css\" rel=\"stylesheet\">");
echo(" </head>");
echo(" <body>");
}
//############################################################################
// Displays HTML Footer
//############################################################################
static function DisplayFooter()
{
echo(" </body>");
echo("</html>");
}
}
All you need now is to include your view from your command:
// Command_BlogIndex.php
//############################################################################
// doExecute
//############################################################################
function doExecute(Request $request)
{
// Create manager object
$manager = new ManagerMessage();
// Get data from database object
$data = $manager->getAllMessages();
// Include view
include("views/index.php");
}
Note: I'll let you create your own style sheet, mine is boring anyway :)
Checkpoint
The home page of your blog should now be working!!!
Step 6 - Adding messages
Next, let’s add a command to add blog messages. You might have noticed above that our “add messages” link (see above) points to “index.php?cmd=BlogAddForm”
So first, you need a new command called “Command_BlogAddForm”. It doesn’t do much, it simply displays the view containing the form. Here is the code:
// Command_BlogAddForm.php
//############################################################################
// SearchVenueCommand class
//############################################################################
class Command_BlogAddForm extends Command
{
//############################################################################
// doExecute
//############################################################################
function doExecute(Request $request)
{
// Include view
include("views/add_form.php");
}
}
And here is the view containing the form:
<!-- views/add_form.php -->
<?require_once("view_helper.php");?>
<?ViewHelper::DisplayHeader("Add message");?>
<h1>Blog add form</h1>
<p>Please fill in the fields</p>
<form action="index.php?cmd=BlogAdd" method="post">
Title:<br><input name="title">
<br>
Message:<br><textarea name="message"></textarea>
<br>
<input type="submit" value="Add">
</form>
<?ViewHelper::DisplayFooter();?>
Again note that the "action" attribute of the <FORM> above points to "index.php?cmd=BlogAdd". So we need another action responsible for reading the user data from the form, and creating a new record in the database... here it is!
// Command_BlogAdd.php
//############################################################################
// Command_BlogAdd class
//############################################################################
class Command_BlogAdd extends Command
{
//############################################################################
// doExecute
//############################################################################
function doExecute(Request $request)
{
// Get data from request
$title = $request->getProperty('title');
$message = $request->getProperty('message');
// Create manager object
$manager = new ManagerMessage();
// Add to database
$manager->addMessage($title, $message);
// Redirect to index
header("location:index.php");
}
}
Note: This action doesn't have a view. It simply redirects the user to the index of the forum.
Checkpoint
You should now be able to add new messages... try it!
Step 7 - Deleting messages
Finally, let’s create a new action in charge of message deletion.
Again if you browse the mouse over the “delete this message” links, you will see URLs such as “index.php?cmd=BlogDelete&id=19”
So we need a new Command_BlogDelete class. Here is the code:
// Command_BlogDelete.php
//############################################################################
// SearchVenueCommand class
//############################################################################
class Command_BlogDelete extends Command
{
//############################################################################
// doExecute
//############################################################################
function doExecute(Request $request)
{
// Get data from request
$id = $request->getProperty('id');
// Create manager object
$manager = new ManagerMessage();
// Add to database
$manager->deleteMessage($id);
// Redirect to index
header("location:index.php");
}
}
Nothing too complicated here...
Checkpoint
You should now be able to delete messages.
Note: It is always better practice to ask users to confirm deletion first... but you can do that bit ;)
