From 45b0fe42a979d444d547a5248eb2e9e915aaf16a Mon Sep 17 00:00:00 2001 From: wei <> Date: Sun, 14 Jan 2007 02:10:24 +0000 Subject: Add "block-content" to allow user comments on block level elements in quickstart docs. --- .../protected/pages/Tutorial/AjaxChat.page | 264 ++++++++-------- .../pages/Tutorial/CurrencyConverter.page | 343 +++++++++++---------- 2 files changed, 317 insertions(+), 290 deletions(-) (limited to 'demos/quickstart/protected/pages/Tutorial') diff --git a/demos/quickstart/protected/pages/Tutorial/AjaxChat.page b/demos/quickstart/protected/pages/Tutorial/AjaxChat.page index 2d49c9f6..ec6fc149 100644 --- a/demos/quickstart/protected/pages/Tutorial/AjaxChat.page +++ b/demos/quickstart/protected/pages/Tutorial/AjaxChat.page @@ -1,67 +1,67 @@ -

Building an AJAX Chat Application

This tutorial introduces the Prado web application framework's +

Building an AJAX Chat Application

This tutorial introduces the Prado web application framework's ActiveRecord - and Active Controls to build a Chat - web application. It is assumed that you + and Active Controls to build a Chat + web application. It is assumed that you are familiar with PHP and you have access to a web server that is able to serve PHP5 scripts. This basic chat application will utilize the following ideas/components in Prado. -

Building a custom User Manager class.
Authenticating and adding a new user to the database.
Using ActiveRecord to interact with the database.
Using Active Controls and callbacks to implement the user interface.
Separating application logic and application flow.

In this tutorial you will build an AJAX Chat web application that allows - multiple users to communicate through their web browser. +

In this tutorial you will build an AJAX Chat web application that allows + multiple users to communicate through their web browser. The application consists of two pages: a login page that asks the user to enter their nickname and the main application chat page. - You can try the application locally or at + You can try the application locally or at Pradosoft.com. - The main application chat page is shown bellow. + The main application chat page is shown bellow. class="figure" />

Download, Install and Create a New Application

The download and installation steps are similar to those in +

Download, Install and Create a New Application

The download and installation steps are similar to those in the Currency converter tutorial. To create the application, we run from the command line the following. - See the Command Line Tool + See the Command Line Tool for more details. - + php prado/framework/prado-cli.php -c chat - +

The above command creates the necessary directory structure and minimal +

The above command creates the necessary directory structure and minimal files (including "index.php" and "Home.page") to run a Prado web application. Now you can point your browser's URL to the web server to serve up the index.php script in the chat directory. - You should see the message "Welcome to Prado!" + You should see the message "Welcome to Prado!"

Authentication and Authorization

The first task for this application is to ensure that each user - of the chat application is assigned with a unique (chosen by the user) +

Authentication and Authorization

The first task for this application is to ensure that each user + of the chat application is assigned with a unique (chosen by the user) username. To achieve this, we can secure the main chat application page to deny access to anonymous users. First, let us create the Login page with the following code. We save the Login.php and Login.page in the chat/protected/pages/ directory (there should be a Home.page file created by the command line tool).

+ <?php class Login extends TPage { } ?> - - + @@ -87,7 +87,7 @@ class Login extends TPage -

The login page contains +

The login page contains a , a , a @@ -99,12 +99,12 @@ class Login extends TPage due to the requiring the user to enter some text in the textbox before proceeding.

Securing the `Home` page

Now we wish that if the user is trying to access the main application +

Securing the `Home` page

Now we wish that if the user is trying to access the main application page, Home.page, before they have logged in, the user is presented with the Login.page first. We add a chat/protected/application.xml configuration file to import some classes that we shall use later. - + @@ -117,7 +117,7 @@ file to import some classes that we shall use later. Next, we add a chat/protected/pages/config.xml configuration file to secure the pages directory. - + @@ -131,41 +131,41 @@ secure the pages directory. -We setup the authentication using the default classes as explained in the +We setup the authentication using the default classes as explained in the authentication/authorization quickstart. -In the authorization definition, we allow anonymous users to access the +In the authorization definition, we allow anonymous users to access the Login page (anonymous users is specified by the ? question mark). -We allow any users with role equal to "normal" (to be defined later) +We allow any users with role equal to "normal" (to be defined later) to access all the pages, that is, the Login and Home pages. Lastly, we deny all users without any roles to access any page. The authorization rules are executed on first match basis.

If you now try to access the Home page by pointing your browser +

If you now try to access the Home page by pointing your browser to the index.php you will be redirected to the Login page.

Active Record for `chat_users` table

The +

Active Record for `chat_users` table

The class only provides a read-only list of users. We need to be able to add or login new users dynamically. So we need to create our own user manager class. -First, we shall setup a database with a chat_users table and create an ActiveRecord +First, we shall setup a database with a chat_users table and create an ActiveRecord that can work with the chat_users table with ease. For the demo, we use sqlite as our database for ease of distributing the demo. The demo can be extended to use other databases such as MySQL or Postgres SQL easily. We define the chat_users table as follows. - -CREATE TABLE chat_users -( - username VARCHAR(20) NOT NULL PRIMARY KEY, - last_activity INTEGER NOT NULL DEFAULT "0" + +CREATE TABLE chat_users +( + username VARCHAR(20) NOT NULL PRIMARY KEY, + last_activity INTEGER NOT NULL DEFAULT "0" ); Next we define the corresponding ChatUserRecord class and save it as chat/protected/App_Code/ChatUserRecord.php (you need to create the App_Code directory as well). We also save the sqlite database file as App_Code/chat.db. - + class ChatUserRecord extends TActiveRecord { public $username; @@ -181,9 +181,9 @@ class ChatUserRecord extends TActiveRecord Before using the ChatUserRecord class we to configure a default database connection for ActiveRecord to function. In the chat/protected/application.xml -we import classes from the App_Code directory and add an +we import classes from the App_Code directory and add an ActiveRecord configuration module. - + @@ -201,14 +201,14 @@ we import classes from the App_Code directory and add an

Custom User Manager class

To implement a custom user manager module class we just need +

Custom User Manager class

To implement a custom user manager module class we just need to extends the TModule class and implement the IUserManager interface. The getGuestName(), getUser() and validateUser() methods are required by the IUserManager interface. We save the custom user manager class as App_Code/ChatUserManager.php. -

- +

+ class ChatUserManager extends TModule implements IUserManager { public function getGuestName() @@ -219,7 +219,7 @@ class ChatUserManager extends TModule implements IUserManager public function getUser($username=null) { $user=new TUser($this); - $user->setIsGuest(true); + $user->setIsGuest(true); if($username !== null && $this->usernameExists($username)) { $user->setIsGuest(false); @@ -228,7 +228,7 @@ class ChatUserManager extends TModule implements IUserManager } return $user; } - + public function addNewUser($username) { $user = new ChatUserRecord(); @@ -249,7 +249,7 @@ class ChatUserManager extends TModule implements IUserManager } } -

The getGuestName() method simply returns the name for a guest user and is not used in our application. The getUser() method returns a TUser object if the username @@ -257,25 +257,25 @@ exists in the database, the TUser object is set with role of "normal" that corresponds to the <authorization> rules defined in our config.xml file.

The addNewUser() and usernameExists() -method uses the ActiveRecord corresponding to the chat_users table to +

The addNewUser() and usernameExists() +method uses the ActiveRecord corresponding to the chat_users table to add a new user and to check if a username already exists, respectively.

The next thing to do is change the config.xml configuration to use +

The next thing to do is change the config.xml configuration to use our new custom user manager class. We simply change the <module> configuration with id="users".

- + -

Authentication

To perform authentication, we just want the user to enter a unique -username. We add a +

Authentication

To perform authentication, we just want the user to enter a unique +username. We add a for validate the uniqueness of the username and add an OnClick event handler for the login button.

- + <com:TCustomValidator ControlToValidate="username" Display="Dynamic" @@ -287,7 +287,7 @@ for the login button.

<com:TButton Text="Login" OnClick="createNewUser" /> In the Login.php file, we add the following 2 methods. - + function checkUsername($sender, $param) { $manager = $this->Application->Modules['users']; @@ -301,7 +301,7 @@ function createNewUser($sender, $param) { $manager = $this->Application->Modules['users']; $manager->addNewUser($this->username->Text); - + //do manual login $user = $manager->getUser($this->username->Text); $auth = $this->Application->Modules['auth']; @@ -314,15 +314,15 @@ function createNewUser($sender, $param) } The checkUserName() method uses the ChatUserManager class -(recall that in the config.xml configuration we set the +(recall that in the config.xml configuration we set the ID of the custom user manager class as "users") to validate the username is not taken.

-In the createNewUser method, when the validation passes (that is, +

+In the createNewUser method, when the validation passes (that is, when the user name is not taken) we add a new user. Afterward we perform -a manual login process: -

First we obtain a TUser instance from our custom user manager class using the $manager->getUser(...) method.
Using the TAuthManager we set/update the user object in the @@ -330,20 +330,22 @@ our custom user manager class using the $manager->getUser(...) method.<
Then we set/update the Application's user instance with our new user object.

Finally, we redirect the client to the default Home page.

Default Values for ActiveRecord

If you try to perform a login now, you will receive an error message like -"Property 'ChatUserRecord::$last_activity' must not be null as defined +

Default Values for ActiveRecord

+
If you try to perform a login now, you will receive an error message like +"Property 'ChatUserRecord::$last_activity' must not be null as defined by column 'last_activity' in table 'chat_users'.". This means that the $last_activity property value was null when we tried to insert a new record. We need to either define a default value in the corresponding column in the table and allow null values or set the default -value in the ChatUserRecord class. We shall demonstrate the later by +value in the ChatUserRecord class. We shall demonstrate the later by altering the ChatUserRecord with the addition of a set getter/setter methods for the last_activity property. - + private $_last_activity; public function getLast_Activity() @@ -362,13 +364,13 @@ Notice that we renamed $last_activity to $_last_activity (note the underscore after the dollar sign).
-
Main Chat Application
-
Now we are ready to build the main chat application. We use a simple +
Main Chat Application
+
Now we are ready to build the main chat application. We use a simple layout that consist of one panel holding the chat messages, one panel to hold the users list, a textarea for the user to enter the text message and a button to send the message. - - + @@ -378,7 +380,7 @@ and a button to send the message. { width: 500px; height: 300px; - float: left; + float: left; border: 1px solid ButtonFace; overflow: auto; } @@ -400,7 +402,7 @@ and a button to send the message. .message-input textarea { margin-top: 3px; - padding: 0.4em 0.2em; + padding: 0.4em 0.2em; width: 493px; font-family: Verdana, Geneva, Arial, Helvetica, sans-serif; font-size: 0.85em; @@ -414,7 +416,7 @@ and a button to send the message. <com:TForm> -
Prado Chat Demo
+
Prado Chat Demo

<com:TPlaceHolder ID="messageList" />
@@ -422,9 +424,9 @@ and a button to send the message. <com:TPlaceHolder ID="userList" />
- <com:TActiveTextBox ID="userinput" + <com:TActiveTextBox ID="userinput" Columns="40" Rows="2" TextMode="MultiLine" /> - <com:TActiveButton ID="sendButton" CssClass="send-button" + <com:TActiveButton ID="sendButton" CssClass="send-button" Text="Send" />
</com:TForm> @@ -436,23 +438,23 @@ We added two Active Control components: a and a . -We also added a +We also added a that will be very useful for understanding how the Active Controls work.
-
Exploring the Active Controls
-
We should have some fun before we proceeding with setting up the chat buffering. We want +
Exploring the Active Controls
+
We should have some fun before we proceeding with setting up the chat buffering. We want to see how we can update the current page when we receive a message. First, we add an OnClick event handler for the Send button. - -<com:TActiveButton ID="sendButton" CssClass="send-button" + +<com:TActiveButton ID="sendButton" CssClass="send-button" Text="Send" OnClick="processMessage"/> And the corresponding event handler method in the Home.php class (we need to create this new file too). - + class Home extends TPage { function processMessage($sender, $param) @@ -465,12 +467,12 @@ If you now type something in the main application textbox and click the send but you should see whatever you have typed echoed in the TJavascriptLogger console.
-
To append or add some content to the message list panel, we need to use -some methods in the +
To append or add some content to the message list panel, we need to use +some methods in the class which is available through the CallbackClient property of the current TPage object. For example, we do can do - + function processMessage($sender, $param) { $this->CallbackClient->appendContent("messages", $this->userinput->Text); @@ -480,24 +482,24 @@ This is one way to update some part of the existing page during a callback (AJAX and will be the primary way we will use to implement the chat application.
-
Active Record for chat_buffer table
-
To send a message to all the connected users we need to buffer or store +
Active Record for chat_buffer table
+
To send a message to all the connected users we need to buffer or store the message for each user. We can use the database to buffer the messages. The chat_buffer table is defined as follows. - -CREATE TABLE chat_buffer -( - id INTEGER PRIMARY KEY, - for_user VARCHAR(20) NOT NULL, - from_user VARCHAR(20) NOT NULL, - message TEXT NOT NULL, - created_on INTEGER NOT NULL DEFAULT "0" + +CREATE TABLE chat_buffer +( + id INTEGER PRIMARY KEY, + for_user VARCHAR(20) NOT NULL, + from_user VARCHAR(20) NOT NULL, + message TEXT NOT NULL, + created_on INTEGER NOT NULL DEFAULT "0" ); The corresponding ChatBufferRecord class is saved as App_Code/ChatBufferRecord.php. - + class ChatBufferRecord extends TActiveRecord { public $id; @@ -528,12 +530,12 @@ class ChatBufferRecord extends TActiveRecord
-
Chat Application Logic
-
We finally arrive at the guts of the chat application logic. First, we +
Chat Application Logic
+
We finally arrive at the guts of the chat application logic. First, we need to save a received message into the chat buffer for all the current users. We add this logic in the ChatBufferRecord class. - + public function saveMessage() { foreach(ChatUserRecord::finder()->findAll() as $user) @@ -557,19 +559,20 @@ we update the message sender's last activity timestamp. The above piece of code demonstrates the simplicity and succinctness of using ActiveRecords for simple database designs.
-
The next piece of the logic is to retrieve the users' messages from the buffer. +
The next piece of the logic is to retrieve the users' messages from the buffer. We simply load all the messages for a particular username and format that message appropriately (remember to escape the output to prevent Cross-Site Scripting attacks). After we load the messages, we delete those loaded messages and any older -messages that may have been left in the buffer. +messages that may have been left in the buffer.
- + public function getUserMessages($user) { $content = ''; foreach($this->findAll('for_user = ?', $user) as $message) $content .= $this->formatMessage($message); - $this->deleteAll('for_user = ? OR created_on < ?', $user, time() - 300); //5 min inactivity + $this->deleteAll('for_user = ? OR created_on < ?', + $user, time() - 300); //5 min inactivity return $content; } @@ -577,14 +580,15 @@ protected function formatMessage($message) { $user = htmlspecialchars($message->from_user); $content = htmlspecialchars($message->message); - return "
{$user}: {$content}
"; + return "
{$user}:" + ." {$content}
"; } To retrieve a list of current users (formatted), we add this logic to the ChatUserRecord class. We delete any users that may have been inactive for awhile. - + public function getUserList() { $this->deleteAll('last_activity < ?', time()-300); //5 min inactivity @@ -604,11 +608,11 @@ a TRepeater in the template or a custom component).
-
Putting It Together
-
Now comes to put the application flow together. In the Home.php we update +
Putting It Together
+
Now comes to put the application flow together. In the Home.php we update the Send buttons OnClick event handler to use the application logic we just implemented. - + function processMessage($sender, $param) { if(strlen($this->userinput->Text) > 0) @@ -617,7 +621,7 @@ function processMessage($sender, $param) $record->message = $this->userinput->Text; $record->from_user = $this->Application->User->Name; $record->saveMessage(); - + $this->userinput->Text = ''; $messages = $record->getUserMessages($this->Application->User->Name); $this->CallbackClient->appendContent("messages", $messages); @@ -630,17 +634,17 @@ for the current user and update the client side message list using a callback response (AJAX style).
-
At this point the application is actually already functional, just not very +
At this point the application is actually already functional, just not very user friendly. If you open two different browsers, you should be able to communicate between the two users whenever the Send button is clicked.
-
The next part is perhaps the more tricker and fiddly than the other tasks. We +
The next part is perhaps the more tricker and fiddly than the other tasks. We need to improve the user experience. First, we want a list of current users as well. So we add the following method to Home.php, we can call this method when ever some callback event is raised, e.g. when the Send button is clicked. - + protected function refreshUserList() { $lastUpdate = $this->getViewState('userList',''); @@ -654,13 +658,13 @@ protected function refreshUserList()
-
Actually, we want to periodically update the messages and user list as new +
Actually, we want to periodically update the messages and user list as new users join in and new message may arrive from other users. So we need to refresh the message list as well.
- + function processMessage($sender, $param) { - ... + ... $this->refreshUserList(); $this->refreshMessageList(); ... @@ -681,14 +685,14 @@ protected function refreshMessageList() } The anchor using time() as ID for a focus point is so that when the -message list on the client side gets very long, the focus method will +message list on the client side gets very long, the focus method will scroll the message list to the latest message (well, it works in most browsers).
-
Next, we need to redirect the user back to the login page if the user has +
Next, we need to redirect the user back to the login page if the user has been inactive for some time, say about 5 mins, we can add this check to any stage of the page life-cycle. Lets add it to the onLoad() stage. - + public function onLoad($param) { $username = $this->Application->User->Name; @@ -704,18 +708,18 @@ public function onLoad($param)
-
Improving User Experience
-
The last few details are to periodically check for new messages and +
Improving User Experience
+
The last few details are to periodically check for new messages and refresh the user list. We can accomplish this by polling the server using a control. We add a TTimeTriggeredCallback to the Home.page and call the refresh handler method defined in Home.php. We set the polling interval to 2 seconds. - -<com:TTimeTriggeredCallback OnCallback="refresh" + +<com:TTimeTriggeredCallback OnCallback="refresh" Interval="2" StartTimerOnLoad="true" /> - + function refresh($sender, $param) { $this->refreshUserList(); @@ -724,12 +728,12 @@ function refresh($sender, $param)
-
The final piece requires us to use some javascript. We want that when the +
The final piece requires us to use some javascript. We want that when the user type some text in the textarea and press the Enter key, we want it to send the message without clicking on the Send button. We add to the Home.page some javascript. - + <com:TClientScript> Event.observe($("<%= $this->userinput->ClientID %>"), "keypress", function(ev) { @@ -742,11 +746,11 @@ Event.observe($("<%= $this->userinput->ClientID %>"), "keypress", function }); </com:TClientScript> -Details regarding the javascript can be explored in the +Details regarding the javascript can be explored in the Introduction to Javascript section of the quickstart.
-
This completes the tutorial on making a basic chat web application using +
This completes the tutorial on making a basic chat web application using the Prado framework. Hope you have enjoyed it.
diff --git a/demos/quickstart/protected/pages/Tutorial/CurrencyConverter.page b/demos/quickstart/protected/pages/Tutorial/CurrencyConverter.page index c11c1b94..43666560 100644 --- a/demos/quickstart/protected/pages/Tutorial/CurrencyConverter.page +++ b/demos/quickstart/protected/pages/Tutorial/CurrencyConverter.page @@ -1,59 +1,60 @@ -
Building a Simple Currency Converter
-
This tutorial introduces the Prado web application framework and teaches +
Building a Simple Currency Converter
+
This tutorial introduces the Prado web application framework and teaches you how to build a simple web application in a few simple steps. This tutorial assumes that you are familiar with PHP and you have access to a web server that is able to serve PHP5 scripts. -
- -
In this tutorial you will build a simple web application that converts - a dollar amount to an other currency, given the rate of that currency +
+ +
In this tutorial you will build a simple web application that converts + a dollar amount to an other currency, given the rate of that currency relative to the dollar. The completed application is shown bellow. class="figure" /> - You can try the application locally or at + You can try the application locally or at Pradosoft.com. Notice that the application still functions exactly the same if javascript is not available on the user's browser.
- +
Downloading and Installing Prado
-
To install Prado, simply download the latest version of Prado from +
To install Prado, simply download the latest version of Prado from http://www.pradosoft.com - and unzip the file to a directory not accessible by your web server + and unzip the file to a directory not accessible by your web server (you may unzip it to a directory accessible by the web server if you wish - to see the demos and test). For further detailed installation, see the + to see the demos and test). For further detailed installation, see the Quickstart Installation guide.
- -
Creating a new Prado web Application
-
The quickest and simplest way to create a new Prado web application is + +
Creating a new Prado web Application
+
The quickest and simplest way to create a new Prado web application is to use the command tool prado-cli.php found in the framework - directory of the Prado distribution. We create a new application by running + directory of the Prado distribution. We create a new application by running the following command in your - command prompt or console. The command creates a new directory named - currency-converter in your current working directory. + command prompt or console. The command creates a new directory named + currency-converter in your current working directory. You may need to change to the appropriate directory first. - + See the Command Line Tool + for more details. +
+ php prado/framework/prado-cli.php -c currency-converter - - See the Command Line Tool - for more details. -
- -
The above command creates the necessary directory structure and minimal + + +
The above command creates the necessary directory structure and minimal files (including "index.php" and "Home.page") to run a Prado web application. Now you can point your browser's url to the web server to serve up the index.php script in the currency-converter directory. - You should see the message "Welcome to Prado!" + You should see the message "Welcome to Prado!"
- -
Creating the Currency Converter User Interface
-
We start by editing the Home.page file found in the + +
Creating the Currency Converter User Interface
+
We start by editing the Home.page file found in the currency-converter/protected/pages/ directory. Files ending - with ".page" are page templates that contains HTML and Prado controls. - We simply add two textboxes, three labels and one button as follows. - + with ".page" are page templates that contains HTML and Prado controls. + We simply add two textboxes, three labels and one button as follows. +
+ <com:TForm>
Currency Converter @@ -74,87 +75,93 @@ php prado/framework/prado-cli.php -c currency-converter
</com:TForm> - + +
If you refresh the page, you should see something similar to the following figure. It may not look very pretty or orderly, but we shall change that later using CSS. class="figure" />
- -
- The first component we add is a + +
+ The first component we add is a that basically corresponds to the HTML <form> element. - In Prado, only one TForm element is allowed per page. -
- -
The next two pair of component we add is the + In Prado, only one TForm element is allowed per page. +
+ +
The next two pair of component we add is the - and + and that basically defines a label and a textbox for the user of the application - to enter the currency exchange rate. + to enter the currency exchange rate. The ForControl property value determines which component that the label is for. This allows the user of the application to click on the label to focus on the field (a good thing). You could have used a plain HTML <label> element to do the same thing, but - you would have to find the correct ID of the textbox (or - <input> in HTML) as Prado components may/will render the + you would have to find the correct ID of the textbox (or + <input> in HTML) as Prado components may/will render the ID value differently in the HTML output.
- -
The next pair of components are similar and defines the textbox + +
The next pair of components are similar and defines the textbox to hold the dollar value to be converted. The TLabel with ID value "total" defines a simple label. Notice that the ForControl property is absent. This means that this label is simply a simple label which we are going to use to display the converted total amount.
- -
The final component is a + +
The final component is a that the user will click to calculate the results. The Text property sets the button label.
- -
Implementing Currency Conversion
- -
If you tried clicking on the "Convert" button then the page will refresh + +
Implementing Currency Conversion
+ +
If you tried clicking on the "Convert" button then the page will refresh and does not do anything else. For the button to do some work, we need to add a "Home.php" to where "Home.page" is. The Home class should extends the , the default base - class for all Prado pages. - + class for all Prado pages. +
+ <?php class Home extends TPage { - + } ?> - + +
Prado uses PHP's __autoload method to load classes. The convention - is to use the class name with ".php" extension as filename. + is to use the class name with ".php" extension as filename.
- -
So far there is nothing interesting about Prado, we just declared some + +
So far there is nothing interesting about Prado, we just declared some "web components" in some template file named Home.page and created a "Home.php" file with a Home class. The more interesting bits are in Prado's event-driven architecture as we shall see next.
- -
We want that when the user click on the "Convert" button, we take the + +
We want that when the user click on the "Convert" button, we take the values in the textbox, do some calculation and present the user with the converted total. To handle the user clicking of the "Convert" button we simply add an OnClick property to the "Convert" button in - the "Home.page" template and add a corresponding event handler method - in the "Home.php". - + the "Home.page" template and add a corresponding event handler method + in the "Home.php". +
+ <com:TButton Text="Convert" OnClick="convert_clicked" /> - + +
The value of the OnClick, "convert_clicked", will be the method - name in the "Home.php" that will called when the user clicks on the - "Convert" button. - + name in the "Home.php" that will called when the user clicks on the + "Convert" button. +
+ class Home extends TPage { public function convert_clicked($sender, $param) @@ -164,67 +171,78 @@ class Home extends TPage $this->total->Text = $rate * $dollars; } } - + +
+
If you run the application in your web browser, enter some values and click the "Convert" button then you should see that calculated value displayed next to the "Amount in Other Currency" label.
- -
In the "convert_clicked" method the first parameter, $sender, - corresponds to the object that raised the event, in this case, + +
In the "convert_clicked" method the first parameter, $sender, + corresponds to the object that raised the event, in this case, the "Convert" button. The second parameter, $param contains any additional data that the $sender object may wish to have added.
- -
We shall now examine, the three lines that implements the simply currency - conversion in the "convert_clicked" method. - -$rate = floatval($this->currencyRate->Text); - + +
We shall now examine, the three lines that implements the simply currency + conversion in the "convert_clicked" method. +
+
+ +$rate = floatval($this->currencyRate->Text); + +
The statement $this->currencyRate corresponds to the TTextBox component with ID value "currencyRate" in the "Home.page" template. The Text property of the TTextBox contains the value that the user entered. So, we obtain this value by $this->currencyRate->Text which we convert the - value to a float value. - -$dollars = floatval($this->dollars->Text); - + value to a float value. +
+ +$dollars = floatval($this->dollars->Text); + +
+
The next line does a similar things, it takes the user value from - the TTextBox with ID value "dollars and converts it to + the TTextBox with ID value "dollars and converts it to a float value.
- -
The third line calculates the new amount and set this value in the + +
The third line calculates the new amount and set this value in the Text property of the TLabel with ID="total". - Thus, we display the new amount to the user in the label. - -$this->total->Text = $rate * $dollars; - + Thus, we display the new amount to the user in the label.
- -
Adding Validation
-
The way we convert the user entered value to float ensures that the - total amount is always a number. So the user is free to enter what +
+ +$this->total->Text = $rate * $dollars; + + +
Adding Validation
+
The way we convert the user entered value to float ensures that the + total amount is always a number. So the user is free to enter what ever they like, they could even enter letters. The user's experience in using the application can be improved by adding validators - to inform the user of the allowed values in the currency rate and the + to inform the user of the allowed values in the currency rate and the amount to be calcuated.
- -
For the currency rate, we should ensure that -
+ +
For the currency rate, we should ensure that
+

the user enters a value,
-
the currency rate is a valid number,
+
the currency rate is a valid number,

the currency rate is positive.
-
- To ensure 1 we add one - . To ensure 2 and 3, we add one +
+
+ To ensure 1 we add one + . To ensure 2 and 3, we add one . We may add these validators any where within the "Home.page" template. Further details regarding these validator and other - validators can be found in the - Validation Controls page. - + validators can be found in the + Validation Controls page. +
+ <com:TRequiredFieldValidator ControlToValidate="currencyRate" ErrorMessage="Please enter a currency rate." /> @@ -235,18 +253,19 @@ $this->total->Text = $rate * $dollars; Operator="GreaterThan" ErrorMessage="Please enter a positive currency rate." /> -
- -
For the amount to be calculated, we should ensure that -
+ +
For the amount to be calculated, we should ensure that
+

the user enters a value,

the value is a valid number (not including any currency or dollar signs).
-
+
+
To ensure 1 we just add another TRequiredFieldValidator, for 2 we could use a . For simplicity we only allow the user to enter - a number for the amount they wish to convert. - + a number for the amount they wish to convert. +
+ <com:TRequiredFieldValidator ControlToValidate="dollars" ErrorMessage="Please enter the amount you wish to calculate." /> @@ -256,16 +275,17 @@ $this->total->Text = $rate * $dollars; ErrorMessage="Please enter a number." />
- -
Now if you try to enter some invalid data in the application or left out + +
Now if you try to enter some invalid data in the application or left out any of the fields the validators will be activated and present the user with error messages. Notice that the error messages are presented without reloading the page. Prado's validators by default validates using both javascript and server side. The server side validation is always performed. For the server side, we - should skip the calculation if the validators are not satisfied. This can - done as follows. - + should skip the calculation if the validators are not satisfied. This can + done as follows. +
+ public function convert_clicked($sender, $param) { if($this->Page->IsValid) @@ -274,42 +294,43 @@ public function convert_clicked($sender, $param) $dollars = floatval($this->dollars->Text); $this->total->Text = $rate * $dollars; } -} - -
- -
Improve User Experience With Active Controls
-
In this simple application we may further improve the user experience +} + + +
Improve User Experience With Active Controls
+
In this simple application we may further improve the user experience by decreasing the responsiveness of the application. One way to achieve a faster response is calculate and present the results without reloading the whole page.
- -
We can replace the TButton with the Active Control counter part, + +
We can replace the TButton with the Active Control counter part, , that can trigger a server side click event without reloading the page. - In addition, we can change the "totals" TLabel with the - Active Control counter part, + In addition, we can change the "totals" TLabel with the + Active Control counter part, , such that the server side can update the browser without - reloading the page. - + reloading the page. +
+
Amount in Other Currency: <com:TActiveLabel ID="total" CssClass="result" />

<com:TActiveButton Text="Convert" OnClick="convert_clicked" /> -
- + + +
The server side logic remains the same, we just need to import the Active Controls name space as they are not included by default. We - add the following line to the begin of "Home.php". - -Prado::using('System.Web.UI.ActiveControls.*'); - + add the following line to the begin of "Home.php".
- -
If you try the application now, you may notice that the page no longer + +Prado::using('System.Web.UI.ActiveControls.*'); + + +
If you try the application now, you may notice that the page no longer needs to reload to calculate and display the converted total amount. However, since there is not page reload, there is no indication or not obvious that by clicking on the "Convert" button any has happened. @@ -317,59 +338,61 @@ Prado::using('System.Web.UI.ActiveControls.*'); to "calculating..." when the user clicks on the "Convert" button. The text of the "total" label will still be updated with the new calculate amount as before.
- -
To indicate that the calculation is in progress, we can change the text + +
To indicate that the calculation is in progress, we can change the text of the "total" label as follows. We add a ClientSide.OnLoading property to the "Convert" button (since this button is responsible for requesting - the calculation). - + the calculation). +
+ <com:TActiveButton Text="Convert" OnClick="convert_clicked" > <prop:ClientSide.OnLoading> $('<%= $this->total->ClientID %>').innerHTML = "calculating..." </prop:ClientSide.OnLoading> -</com:TActiveButton> +</com:TActiveButton> -
- -
The ClientSide.OnLoading and various - accept a javascript block as their content or value. - The javascript code $('...') is a javascript function that is + +
The ClientSide.OnLoading and various + accept a javascript block as their content or value. + The javascript code $('...') is a javascript function that is equivalent to document.getElementById('...') that takes a string with the ID of an HTML element. Since Prado renders its components's IDs, we need to use the rendered ID of the "total" label, that is, $this->total->ClientID. We place this bit of code within a <%= %> to obtain the rendered HTML ID for the "total" label. The rest of the javascript code innerHTML = "calculating..." simply changes the content of the "total" label.
- -
Adding Final Touches
-
So far we have built a simple currency converter web application with + +
Adding Final Touches
+
So far we have built a simple currency converter web application with little attention of the looks and feel. Now we can add a stylesheet to improve the overall appearance of the application. We can simply add the stylesheet inline with the template code or we may create a "theme".
- -
To create and use a theme with Prado applications, we simply create a new + +
To create and use a theme with Prado applications, we simply create a new directory "themes/Basic" in the currency-converter directory. You may need to create the themes directory first. Any directory within the themes are considered as a theme with the - name of the theme being the directory name. See the + name of the theme being the directory name. See the Themes and Skins for further details.
- -
We simply create a CSS file named "common.css" and save it in the + +
We simply create a CSS file named "common.css" and save it in the themes/Basic directory. Then we add the following code - to the beginning of "Home.page" (we add a little more HTML as well). - + to the beginning of "Home.page" (we add a little more HTML as well). +
+ <%@ Theme="Basic" %> - <com:THead Title="Currency Converter" /> - - - The first line <%@ Theme="Basic" %> defines the - theme to be used for this page. The + + +
+ The first line <%@ Theme="Basic" %> defines the + theme to be used for this page. The corresponds to the HTML <head> element. In addition to display the Title property by the THead, all CSS -- cgit v1.2.3

Building an AJAX Chat Application

Building an AJAX Chat Application

Download, Install and Create a New Application

Download, Install and Create a New Application

Authentication and Authorization

Authentication and Authorization

Securing the Home page

Securing the Home page

Active Record for chat_users table

Active Record for chat_users table

Custom User Manager class

Custom User Manager class

Authentication

Authentication

Default Values for ActiveRecord

Default Values for ActiveRecord

Main Chat Application

Main Chat Application

Prado Chat Demo

Prado Chat Demo

Exploring the Active Controls

Exploring the Active Controls

Active Record for chat_buffer table

Active Record for chat_buffer table

Chat Application Logic

Chat Application Logic

Putting It Together

Putting It Together

Improving User Experience

Improving User Experience

Building a Simple Currency Converter

Building a Simple Currency Converter

Downloading and Installing Prado

Creating a new Prado web Application

Creating a new Prado web Application

Creating the Currency Converter User Interface

Creating the Currency Converter User Interface

Implementing Currency Conversion

Implementing Currency Conversion

Adding Validation

Adding Validation

Improve User Experience With Active Controls

Improve User Experience With Active Controls

Adding Final Touches

Adding Final Touches

Securing the `Home` page

Securing the `Home` page

Active Record for `chat_users` table

Active Record for `chat_users` table

Active Record for `chat_buffer` table

Active Record for `chat_buffer` table