Handling Entries for a Blogger Built with PHP - Defining the displayHeader() and displayFooter() methods (
Page 5 of 5 )
Having provided the "BlogProcessor" class with the ability to display the web forms required for inserting and updating blog entries, the only step that remains still undefined is assembling the different sections that compose the main web page of the blogger in question.
In order to address the issues that I mentioned above, I'm going to define two additional methods. The the first one obviously will take care of generating the header of the main page, while the second one will be aimed at rendering the footer.
Now that you know what tasks will be performed by these two new methods, please have a look at their respective signatures. Here they are:
// display page header
private function displayHeader(){
$output=<<<EOD
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-
8859-1" />
<title>Blogger System</title>
<link href="styles.css" rel="stylesheet" type="text/css"
media="screen" />
<script language="javascript" src="valfunctions.js"></script>
</head>
<body>
<h1>PHP-BASED BLOG SYSTEM</h1>
EOD;
return $output;
}
// display page footer
private function displayFooter(){
return '</body></html>';
}
As you can see above, the "displayHeader()" and "displayFooter()" methods are simple wrappers for the respective header and footer sections that comprise the primary web page of the blog application. Also, you should notice that I decided to include a CSS file along with the header, which logically will improve the overall look and feel of the program.
In addition, the "displayHeader()" method includes a JavaScript file called "valfunctions.js" that will take care of performing a basic client-side validation on the data entered in the respective insertion and update web forms. However, both CSS and JavaScript files that I mentioned previously will be shown in the last article of this series, therefore at least for the moment, keep them away of your mind.
Okay, now that you learned the signature for this pair of new methods, I'll create two new useful ones, in this case called "displayMainPage()" and "displayUpdatePage()" respectively. As their names suggest, they will be tasked with rendering the primary web page of the blogger and the update web document.
That said, here are the corresponding definitions for these private methods:
// display main page
private function displayMainPage(){
return $this->displayHeader().$this->displayBlogs
().$this->displayInsertForm().$this->displayFooter();
}
// display edit page
private function displayEditPage(){
return $this->displayHeader().$this-
>displayUpdateForm().$this->displayFooter();
}
Wasn't that simple? The two additional methods that I just created above are the last ones required to complete the blogger. Of course, I'm quite sure that you want to see the full source code that corresponds to the blog application. Below you can see how the complete "BlogProcessor" class now looks:
class BlogProcessor{
private $mysql;
private $blogData;
public function __construct(MySQL $mysql){
$this->mysql=$mysql;
$this->blogData=$_POST;
}
// display blog system
public function displayBlogger(){
// edit blog
if($this->blogData['editblog']){
// display edit page
return $this->displayEditPage();
}
else{
// insert new blog
if($this->blogData['insertblog']){
$this->insertBlog();
}
// update blog
elseif($this->blogData['updateblog']){
$this->updateBlog();
}
// delete blog
elseif($this->blogData['deleteblog']){
$this->deleteBlog();
}
}
// display main page
return $this->displayMainPage();
}
// insert new blog
private function insertBlog(){
$title=$this->blogData['title'];
$author=$this->blogData['author'];
$content=$this->blogData['content'];
$this->mysql->query("INSERT INTO blogs
(id,author,title,content,date) VALUES (NULL,'$author','$title','$content',TIMESTAMP
(10))");
header('Location:'.$_SERVER['PHP_SELF']);
}
// update blog
private function updateBlog(){
$id=$this->blogData['id'];
$title=$this->blogData['title'];
$author=$this->blogData['author'];
$content=$this->blogData['content'];
$this->mysql->query("UPDATE blogs SET
title='$title',author='$author',content='$content',date=TIMESTAMP(10) WHERE
id='$id'");
header('Location:'.$_SERVER['PHP_SELF']);
}
// delete blog
private function deleteBlog(){
$id=$this->blogData['id'];
$title=$this->blogData['title'];
$author=$this->blogData['author'];
$content=$this->blogData['content'];
$this->mysql->query("DELETE FROM blogs WHERE id='$id'");
header('Location:'.$_SERVER['PHP_SELF']);
}
// display all the blogs
private function displayBlogs(){
$result=$this->mysql->query("SELECT * FROM blogs");
$output='';
while($row=$result->fetchRow()){
$content=nl2br($row['content']);
$output.=<<<EOD
<div class="blog">
<h2>$row[title]</h2>
<h3> Author: $row[author]<h3>
<h3> Posted: $row[date]</h3>
<p>$content</p>
<form action="$_SERVER[PHP_SELF]" method="post">
<input type="submit" value="Edit Blog" name="editblog" />
<input type="submit" value="Delete Blog" name="deleteblog" />
<input type="hidden" value="$row[id]" name="id" />
</form>
</div>
EOD;
}
return $output;
}
// display insertion form
private function displayInsertForm(){
$output=<<<EOD
<div class="dataform">
<h2>Insert New Blog</h2>
<form action="$_SERVER[PHP_SELF]" method="post" id="insertform">
<p>Title:</p><p><input type="text" name="title" class="datafield" /></p>
<p>Author:</p><p><input type="text" name="author" class="datafield" /></p>
<p>Type your content below</p><p><textarea
name="content"></textarea></p>
<p><input type="submit" name="insertblog" value="Insert Blog" /></p>
</form>
</div>
EOD;
return $output;
}
// display update form
private function displayUpdateForm(){
$id=$this->blogData['id'];
$result=$this->mysql->query("SELECT * FROM blogs WHERE
id='$id'");
if($result->countRows()>0){
$row=$result->fetchRow();
$output=<<<EOD
<div class="dataform">
<h2>Update Blog</h2>
<form action="$_SERVER[PHP_SELF]" method="post" id="updateform">
<p>Title:</p><p><input type="text" name="title" value="$row[title]"
class="datafield" /></p>
<p>Author:</p><p><input type="text" name="author" value="$row[author]"
class="datafield" /></p>
<p>Update your content below</p><p><textarea name="content">$row[content]</textarea></p>
<p><input type="submit" name="updateblog" value="Update Blog" /></p>
<input type="hidden" value="$id" name="id" />
</form>
</div>
EOD;
return $output;
}
}
// display page header
private function displayHeader(){
$output=<<<EOD
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Blogger System</title>
<link href="styles.css" rel="stylesheet" type="text/css" media="screen" />
<script language="javascript" src="valfunctions.js"></script>
</head>
<body>
<h1>PHP-BASED BLOG SYSTEM</h1>
EOD;
return $output;
}
// display page footer
private function displayFooter(){
return '</body></html>';
}
// display main page
private function displayMainPage(){
return $this->displayHeader().$this->displayBlogs().$this-
>displayInsertForm().$this->displayFooter();
}
// display edit page
private function displayEditPage(){
return $this->displayHeader().$this->displayUpdateForm().$this-
>displayFooter();
}
}
Now, after seeing the full source code of the blog application, you'll agree with me that every piece of code makes much more sense. As I say in every article, feel free to tweak the code of each method shown here and introduce your own modifications. It's really fun!
Wrapping up
In this second part of the series, I defined all remaining methods that belong to the blog processor, in order to turn it into an almost fully-functional class. Why did I say "almost"? Well, there's still a couple of things that need to be done, such as defining the MySQL wrapping class aggregated by the blog processor, in addition to defining the CSS and JavaScript files that I mentioned a few lines before.
However, as you'll probably imagine, all these issues will be covered in the last part, so you don't have any excuses to miss it!
