Subversion-Projekte lars-tiefland.prado

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<h1>Creating <tt>EditPost</tt> Page</h1>

<p>

The <tt>EditPost</tt> page is provided to authors and the administrator to edit existing blog posts. Like the <a href="?page=Day4.CreateNewPost">NewPost</a> page, it displays a form to collect the change to the title and content of a post.

</p>

<p>

We create two files <tt>protected/pages/posts/EditPost.page</tt> and <tt>protected/pages/posts/EditPost.php</tt> to save the page template and page class, respectively.

</p>

<h2>Creating Page Template</h2>

<p>

The <tt>EditPost</tt> page template is very similar to the <tt>NewPost</tt> template. Only the page title and the button caption are different.

</p>

<com:TTextHighlighter CssClass="source" Language="prado">

<%@ Title="My Blog - Edit Post" %>

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<h1>Edit Post</h1>

<span>Title:</span>

<com:TRequiredFieldValidator

	ControlToValidate="TitleEdit"

	ErrorMessage="Please provide a title."

	Display="Dynamic" />

<br/>

<com:TTextBox ID="TitleEdit" Columns="50" />

<br/>

<span>Content:</span>

<com:TRequiredFieldValidator

	ControlToValidate="ContentEdit"

	ErrorMessage="Please provide content."

	Display="Dynamic" />

<br/>

<com:THtmlArea ID="ContentEdit" />

<br/>

<com:TButton Text="Save" OnClick="saveButtonClicked" />

</com:TContent>

</com:TTextHighlighter>

<h2>Creating Page Class</h2>

<p>

The <tt>EditPage</tt> page class is slightly complex than <tt>NewPage</tt> because it needs to load the specified post data first. It also needs to perform additional authorization check. In particular, it needs to ensure that a post can only be editted by the author or the administrator. Such authorization check is not provided by PRADO itself.

</p>

<com:TTextHighlighter CssClass="source" Language="php">

class EditPost extends TPage

{

	/**

	 * Initializes the inputs with existing post data.

	 * This method is invoked by the framework when the page is being initialized.

	 * @param mixed event parameter

	 */

	public function onInit($param)

	{

		parent::onInit($param);

		// Retrieves the existing user data. This is equivalent to:

		// $postRecord=$this->getPost();

		$postRecord=$this->Post;

		// Authorization check: only the author or the administrator can edit the post

		if($postRecord->author_id!==$this->User->Name && !$this->User->IsAdmin)

			throw new THttpException(500,'You are not allowed to edit this post.');

		if(!$this->IsPostBack)  // if the page is initially requested

		{

			// Populates the input controls with the existing post data

			$this->TitleEdit->Text=$postRecord->title;

			$this->ContentEdit->Text=$postRecord->content;

		}

	}

	/**

	 * Saves the post if all inputs are valid.

	 * This method responds to the OnClick event of the "Save" button.

	 * @param mixed event sender

	 * @param mixed event parameter

	 */

	public function saveButtonClicked($sender,$param)

	{

		if($this->IsValid)  // when all validations succeed

		{

			// Retrieves the existing user data. This is equivalent to:

			// $postRecord=$this->getPost();

			$postRecord=$this->Post;

			// Fetches the input data

			$postRecord->title=$this->TitleEdit->SafeText;

			$postRecord->content=$this->ContentEdit->SafeText;

			// saves to the database via Active Record mechanism

			$postRecord->save();

			// redirects the browser to the ReadPost page

			$url=$this->Service->constructUrl('posts.ReadPost',array('id'=>$postRecord->post_id));

			$this->Response->redirect($url);

		}

	}

	/**

	 * Returns the post data to be editted.

	 * @return PostRecord the post data to be editted.

	 * @throws THttpException if the post data is not found.

	 */

	protected function getPost()

	{

		// the ID of the post to be editted is passed via GET parameter 'id'

		$postID=(int)$this->Request['id'];

		// use Active Record to look for the specified post ID

		$postRecord=PostRecord::finder()->findByPk($postID);

		if($postRecord===null)

			throw new THttpException(500,'Post is not found.');

		return $postRecord;

	}

}

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<h2>Testing</h2>

<p>

To test the <tt>EditPost</tt> page, login first and visit the following URL: <tt>http://hostname/blog/index.php?page=EditPost&id=1</tt>. This URL can also be reached by clicking on the <tt>Edit</tt> link on a post detail page.

</p>

<img src="<%~ output4.gif %>" class="output" />

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