When developing web applications, you may need to connect to the Facebook API to gather information or make posts for the user. In this article, we will be teaching you how to connect to the Facebook API using the Facebook PHP SDK.
Đang xem: Connecting to the facebook api using the facebook php sdk
Note: If you have not already done so, be sure to prepare the SDK on your development environment by following our guide onobtaining the Facebook SDK.
Full code example
validate() ) {$session = null;}}// Check if an active session exists.if ( !isset( $session ) || $session === null ) {// If no session exists, let”s try to create one.$session = $helper->getSessionFromRedirect();}// Make sure we have a session started.if ( isset( $session ) ) {// Save the session$_SESSION<"fb_token"> = $session->getToken();// Create a new Facebook session using our token.$session = new FacebookSession( $session->getToken() );echo “Connected to Facebook!”;} else {// Show login urlecho “getLoginUrl( array( “email”, “user_friends” ) ) . “”>Login”;}
Walking through the code
Connecting to the Facebook SDK
First, we will need to connect to the Facebook SDK to load all of the required libraries. Thankfully, much of the work is already done for us with theautoload.phpfile that is included with the Facebook SDK. We simply need to include it and reference the required connection classes like so:
// Begin loading the necessary files for the Facebook SDK.require ( “autoload.php” );// Load the required PHP classes from the Facebook SDK.use FacebookFacebookSession;use FacebookFacebookRedirectLoginHelper;use FacebookFacebookRequest;As you can see here, we used therequire()PHP function to include the autoload.php file.
Then, as our connection needs to load a session with Facebook, we have set our code to include theFacebookSession,FacebookRedirectLoginHelper, andFacebookRequestPHP classes to appropriately connect as well as request data from Facebook’s API.
Xem thêm: Nên Học Php Hay Ruby Hay Php? Tại Sao Web Designer Nên Học Ruby On Rails
Starting the session
Now that we have included the required libraries in our code, we need to open a new session. To do so, simply call thesession_star()function:
// Initialize the Facebook app using the application ID and secret.FacebookSession::setDefaultApplication( “xxxxxxxxxxxxxx”,”xxxxxxxxxxxxxxxxxxxxxxxxxxx” );Within this line, you will need to add your Application ID and Secret that is obtained from the Facebook Developers site. If you do not already have an Application ID, you may follow our article on obtaining a Facebook API key.
Now that the application is initialized and your credentials are verified with the Facebook API, a session needs to be created with Facebook. When creating sessions with the Facebook API, the user will be sent to Facebook to log in and authorize the application, then redirected back to your application. In the following lines, we are opening a session with Facebook and preparing to run requests to the Facebook API.
// Define Facebook”s login helper and redirect back to our page.$helper = new FacebookRedirectLoginHelper( “https://local.wordpress.dev/fb/index.php” );// Check to ensure our session was started correctly and the access token exists.if ( isset( $_SESSION ) && isset( $_SESSION<"fb_token"> ) ) {// Using the access token, create a new session.$session = new FacebookSession( $_SESSION<"fb_token"> );// Determine if the defined session is indeed valid.if ( !$session->validate() ) {$session = null;}}// Check if an active session exists.if ( !isset( $session ) || $session === null ) {// If no session exists, let”s try to create one.$session = $helper->getSessionFromRedirect();}
Prompt the user to login or display data
In the next lines, we then need to check to see if there is an active session, then display the content appopriately. If the user is not yet logged in and provided permissions to the application, the user will be prompted with a link to log in and will be returned to the page as per theFacebookRedirectLoginHelperURL. Once the user is returned, they will have a session active and will then be shownConnected to Facebook!in their browser.
// Make sure we have a session started.if ( isset( $session ) ) {// Save the session$_SESSION<"fb_token"> = $session->getToken();// Create a new Facebook session using our token.$session = new FacebookSession( $session->getToken() );echo “Connected to Facebook!”;} else {// Show login urlecho “getLoginUrl( array( “email”, “user_friends” ) ) . “”>Login”;}
Where do I go from here?
Now that you know how to easily connect to the Facebook API using the Facebook SDK for PHP, you can now make queries to Facebook to generate information on users.
praharsh says:
John says:
I haven’t received any errors, however I just don’t have the facebook button appearing. As for the index file, I made a separate one which is located within the same folder as the autoload.php file. Opencart appears to have another index file on the public.html root directory. Should the autoload.php and index.php be placed (or code added) to those on the root drive? Would I also then need to change some code to make sure it pulls up the rest of the information left in the facebook folder I created with the other SDK files?