Subversion-Projekte lars-tiefland.prado

<com:TContent ID="Main">

<h1>Creating <tt>EditUser</tt> Page</h1>

<p>

The <tt>EditUser</tt> page is very similar to the <a href="?page=Day3.CreateNewUser">NewUser</a>. The main difference is that when <tt>EditUser</tt> is initially requested, the input fields should be initialized with existing user information. Another slight difference is that <tt>EditUser</tt> can also be accessed by normal users.

</p>

<p>

To determine which user account is to be editted, we use the following policy:

</p>

<ul>

<li>If the current user is an administrator, he can edit any user account by specifying the account's username in a GET variable named 'username'. For example, <tt>http://hostname/blog/index.php?page=users.EditUser&username=demo</tt>.</li>

<li>If the current user is an administrator and the URl does not contain 'username', the administrator himself's data is being updated.</li>

<li>If the current user is a normal user, he can only edit his own account information, and he cannot modify his role data.</li>

</ul>

<p>

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

</p>

<h2>Creating Page Template</h2>

<p>

As you may have guessed, the page template <tt>EditUser</tt> is largely the same as that of <tt>NewUser</tt>. Besides the difference in page title and the caption of the submit button, there are three main differences.

</p>

<ul>

<li>The "username" text box is replaced by a <a href="http://www.pradosoft.com/demos/quickstart/?page=Controls.Label">TLabel</a> control because we do not allow modifying username;</li>

<li>The validator for the "password" input is removed. This is because if the user does not provide a password during editting, it means the user does not want to change the password.</li>

<li>The "role" input is surrounded with <tt>TControl</tt> whose visibility is toggled according to the role of the currently logged-in user. If the user is not an administrator, the "role" input will not be displayed because normal users are not allowed to modify their roles.</li>

</ul>

</p>

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

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

<com:TContent ID="Main">

<h1>Edit User</h1>

<span>Username:</span>

<com:TLabel ID="Username" />

<br/>

<span>Password:</span>

<br/>

<com:TTextBox ID="Password" TextMode="Password" />

<br/>

<span>Re-type Password:</span>

<com:TCompareValidator

    ControlToValidate="Password"

    ControlToCompare="Password2"

    ErrorMessage="Your password entries did not match."

    Display="Dynamic" />

<br/>

<com:TTextBox ID="Password2" TextMode="Password" />

<br/>

<span>Email Address:</span>

<com:TRequiredFieldValidator

    ControlToValidate="Email"

    ErrorMessage="Please provide your email address."

    Display="Dynamic" />

<com:TEmailAddressValidator

    ControlToValidate="Email"

    ErrorMessage="You entered an invalid email address."

    Display="Dynamic" />

<br/>

<com:TTextBox ID="Email" />

<com:TControl Visible="<%= $this->User->IsAdmin %>">

<br/>

<span>Role:</span>

<br/>

<com:TDropDownList ID="Role">

    <com:TListItem Text="Normal User" Value="0" />

    <com:TListItem Text="Administrator" Value="1" />

</com:TDropDownList>

</com:TControl>

<br/>

<span>First Name:</span>

<br/>

<com:TTextBox ID="FirstName" />

<br/>

<span>Last Name:</span>

<br/>

<com:TTextBox ID="LastName" />

<br/>

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

</com:TContent>

</com:TTextHighlighter>

<h2>Creating Page Class</h2>

<p>

Based on the above description and template, we need to write a page class that initializes the inputs with the existing user information. In addition, the page class also needs to implement the <tt>saveButtonClicked()</tt> method which is attached to the "save" button's <tt>OnClick</tt> event.

</p>

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

class EditUser extends TPage

{

    /**

     * Initializes the inputs with existing user 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);

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

        {

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

            // $userRecord=$this->getUserRecord();

            $userRecord=$this->UserRecord;

            // Populates the input controls with the existing user data

            $this->Username->Text=$userRecord->username;

            $this->Email->Text=$userRecord->email;

            $this->Role->SelectedValue=$userRecord->role;

            $this->FirstName->Text=$userRecord->first_name;

            $this->LastName->Text=$userRecord->last_name;

        }

    }

    /**

     * Saves the user account 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:

            $userRecord=$this->UserRecord;

            // Fetches the input data

            $userRecord->username=$this->Username->Text;

            // update password when the input is not empty

            if(!empty($this->Password->Text))

                $userRecord->password=$this->Password->Text;

            $userRecord->email=$this->Email->Text;

            // update the role if the current user is an administrator

            if($this->User->IsAdmin)

                $userRecord->role=(int)$this->Role->SelectedValue;

            $userRecord->first_name=$this->FirstName->Text;

            $userRecord->last_name=$this->LastName->Text;

            // saves to the database via Active Record mechanism

            $userRecord->save();

            // redirects the browser to the homepage

			$this->Response->redirect($this->Service->DefaultPageUrl);

        }

    }

    /**

     * Returns the user data to be editted.

     * @return UserRecord the user data to be editted.

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

     */

    protected function getUserRecord()

    {

        // the user to be editted is the currently logged-in user

        $username=$this->User->Name;

        // if the 'username' GET var is not empty and the current user

        // is an administrator, we use the GET var value instead.

        if($this->User->IsAdmin && $this->Request['username']!==null)

            $username=$this->Request['username'];

        // use Active Record to look for the specified username

        $userRecord=UserRecord::finder()->findByPk($username);

        if(!($userRecord instanceof UserRecord))

            throw new THttpException(500,'Username is invalid.');

        return $userRecord;

    }

}

</com:TTextHighlighter>

<com:TipBox>

The <tt>onInit()</tt> method is invoked by PRADO during one of the <a href="http://www.pradosoft.com/demos/quickstart/?page=Fundamentals.Pages">page lifecycles</a>. Other commonly overriden lifecycle methods include <tt>onPreInit()</tt>, <tt>onLoad()</tt> and <tt>onPreRender()</tt>.

</com:TipBox>

<h2>Adding Permission Check</h2>

<p>

To make the <tt>EditUser</tt> page also accessible by authenticated users (<tt>users="@"</tt>), we need to adjust the page configuration file <tt>protected/pages/users/config.xml</tt> accordingly.

</p>

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

<?xml version="1.0" encoding="utf-8"?>

<configuration>

  <authorization>

    <allow roles="admin"/>

    <allow users="@" pages="EditUser"/>

    <deny users="*"/>

  </authorization>

</configuration>

</com:TTextHighlighter>

<h2>Testing</h2>

<p>

To test the <tt>EditUser</tt> page, visit the URL <tt>http://hostname/blog/index.php?page=users.EditUser&username=demo</tt>. You may be required to login first if you have not done so. Try logging in with different accounts (e.g. admin/demo, demo/demo) and see how the page displays differently.

</p>

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