Subversion-Projekte lars-tiefland.prado

<com:TContent ID="Main">

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

&lt;com:TContent ID="Main">

<h1>Edit Post</h1>

<span>Title:</span>
&lt;com:TRequiredFieldValidator
        ControlToValidate="TitleEdit"
        ErrorMessage="Please provide a title."
        Display="Dynamic" />
<br/>
&lt;com:TTextBox ID="TitleEdit" Columns="50" />

<br/>
<span>Content:</span>
&lt;com:TRequiredFieldValidator
        ControlToValidate="ContentEdit"
        ErrorMessage="Please provide content."
        Display="Dynamic" />
<br/>
&lt;com:THtmlArea ID="ContentEdit" />

<br/>
&lt;com:TButton Text="Save" OnClick="saveButtonClicked" />

&lt;/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;
        }
}
</com:TTextHighlighter>

<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" />

</com:TContent>