Welcome to the PHP Developer Center

Welcome to the PHP Developer Center

Yahoo! Language centers have been deprecated. If you have any concerns or questions, please don't hesitate to contact us in General Discussion at YDN forum.

From simple scripts to enterprise-class Web applications, PHP is one of the most popular programming languages in the world. This site is your source for information about using PHP with Yahoo! Web Services APIs. Here you'll find:

• Tutorial that shows you how to use PHP to make REST requests and parse XML responses.
• HOWTO Articles to help you understand our technologies and how you can use them better with PHP.
• Code Samples you can play with. Use them as a starting point for your own applications or study them for subtle nuances.
• OAuth Authorization to let Yahoo! users authorize applications.
• Other Resources out on the Web to help you use PHP and the Yahoo! APIs to their fullest.
• Community Resources where you can join our mailing list and discuss the Yahoo! APIs with us and with other PHP developers.

HOWTO Articles

There are many ways probably too many ways to use PHP to access, parse, and cache Yahoo! Web Service requests. In these articles, we give you our recommendations and suggestions for thoughtful and efficient PHP usage. Both PHP4 and PHP5 are covered.
HOWTO: Make Yahoo! Web Service REST Calls with PHP: Should you use curl, fsockopen, or something else? Here are some thoughts on the subject.
HOWTO: Parse Yahoo! Web Service REST Calls with PHP: Yahoo! Web Services return XML. Some can also return JSON and Serialized PHP. We recommend techniques for parsing and accessing all of these data types.
HOWTO: Cache Yahoo! Web Service REST Calls with PHP: Caching is essential for performance and reliability. There are many ways to cache data and we offer up a couple of them.

Code Samples

Sometimes it's easiest to learn by looking at what other people have done. In this section we've included code samples written by us and others to help you get up to speed with Yahoo! Web Services.
Unless otherwise noted, all the folllowing code samples are provided under the terms of the Yahoo! SDK Software License Agreement.

Codes Samples Used by our HOWTOs

Cut to the chase and drill down to what matters. These working code samples, which are used in our HOWTO's above, can get you started quickly.

• cacheAPC - APC caching for Web services
• cacheSWAP - file swap caching for Web services
• parseDOMPHP5 - parsing XML using PHP 5's DOM extension
• parseDOMXML - parsing XML using PHP 4's DOM XML extension
• parseJSON - parsing JSON using JSON-PHP and PHP-JSON
• parsePHP - parsing serialized PHP
• parseSIMPLEXML - parsing XML using PHP5's SimpleXML extension
• requestCURLGET - Web services HTTP GET requests using the curl extension
• requestCURLPOST - Web services HTTP POST requests using the curl extension
• requestFILEGC - Web services HTTP GET requests using file_get_contents

Other Code Samples

• Geocool, Rasmus Lerdorf steps you through Yahoo!'s Geocoder API.
• A fun mash-up map of pottery studio locations by Roy Shroeder.
• Chris Neale's YahooBattle; Search terms battle it out for top ranking using Yahoo! Search.
• Examples of making Yahoo! Web Services requests using fsockopen for both GETs and POSTs.

Libraries

PEAR: PHP Extension and Application Repository. A vast set of libraries designed for PHP programmers. Many useful libraries including ones for SOAP and XML manipulation.
PHP Classes Repository : A library of PHP classes. Great for object-oriented programming projects.
PHP Extension Community Library (PECL) : A large repository of PHP extensions.

OAuth Authorization

Code samples using OAuth Authorization:

• oauth_yahoo on GitHub - Steps through the OAuth Authorization Flow.
• mysocial.phps - Makes OAuth authorized calls to the Yahoo! Social APIs.
• oauth-php-3-legged on GitHub - Uses 3-legged OAuth authorization to post Yahoo! updates.

OAuth Libraries

• Yahoo! Social SDK for PHP - Uses OAuth to make calls to the Yahoo! Social APIs.
• OAuth Libraries - Lists OAuth libraries for many languages, including PHP.

Other Resources

In this section you'll find links to external sites and articles that may be useful as you work with Yahoo! APIs and Web Services with PHP.


General Information Links

www.php.net : Sector Zero-Zero of PHP  — the place to find definitive PHP documentation and news.
PHP Builder : A popular site with many PHP tutorials and code samples.
Sitepoint : Makers of fine books and tutorials on PHP and other Web development tools.
O'Reilly and Associates : Publishers of many of the best books on PHP as well as offers compelling tutorials and news on their Web site.
Zend Developer Zone : Tutorials and code samples from some of PHP's core developers.
Planet PHP : PHP News aggregator with up-to-date news about PHP from blogs and other sources.
PHP Resource Index: Hundreds of links to PHP scripts and resources.


Specific PHP Topics

Top 7 PHP Security Blunders : An overview of common PHP security mistakes that programmers make.
Toughen Forms' Security with an Image : One approach to implementing CAPTCHA using PHP.
PHP5 SOAP Extension : An overview of PHP5's SOAP extension by the extension's author.
Using XML: A PHP Developer's Primer: A series of articles discussing XML manipulation using PHP.


Community Resources

Discuss how to work with the Yahoo! Web Services and other APIs using PHP on the ydn-php mailing list. Please note that this is not a general PHP programming questions list; try to keep your questions focused to discussion about the Yahoo! APIs.

Build a Simple Yahoo! Answers API Webapp with PHP

Build a Simple Yahoo! Answers API Webapp with PHP

The open Yahoo! API is a great resource to work with. There is plenty of documentation for web developers, along with live demos and examples. What makes the application so interesting is how Yahoo! manages so many different online services. Along with their search engine there is also Yahoo! news, maps, weather, and so much more.

For this tutorial I’d like to focus on the Yahoo! Answers API. We will be creating a simple webapp that pulls all recently answered questions from a select few categories. The API delivers results via XML or JSON, so we have the option to build with any backend programming language. Although for this guide I’ll stick to PHP since it’s the most commonly understood backend language.

Live Demo – Download Source Code

Register a New Application

To get going we first need a new developer API key. This is required so that Yahoo! can manage requests onto the network. Also so that developers can’t just make anonymous requests pulling massive amounts of bandwidth.
You’ll need to visit this new projects page and sign into your Yahoo! account. From there you will be asked some very basic questions about your application – doesn’t matter what you fill in as long as it makes sense. After completion you’ll be presented with an API ID that we’ll need on the backend PHP server-side.

Building the Document

Start out by creating a new page index.html which will hold our core page structure. I’ve included a reference to the most recent jQuery library along with an external script.js file. This will hold our Ajax calls once the document is finished.
Below is my exact code from the index file. You’ll notice that I’m including a few sample categories with IDs related to their Yahoo! ID.

<!doctype html>
<html lang="en">
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
  <title>Yahoo! Answers Webapp - Popular Questions</title>
  <meta name="author" content="Jake Rocheleau">
  <link rel="stylesheet" type="text/css" href="style.css">
  <link rel="stylesheet" type="text/css" href="http://fonts.googleapis.com/css?family=Lemon">
  <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.0/jquery.min.js"></script>
  <script type="text/javascript" src="script.js"></script>
<!--[if lt IE 9]>
  <script src="//html5shiv.googlecode.com/svn/trunk/html5.js"></script>
<![endif]-->
</head>

<body>
  <div id="w">
    <h1>Select a Y! Answers Category</h1>
  
    <nav>
      <a href="#" id="396545444">Politics & Government</a>
      <a href="#" id="396545660">Computers & Internet</a>
      <a href="#" id="396545013">Business & Finance</a>
      <a href="#" id="396545122">Science & Mathematics</a>
      <a href="#" id="396545015">Education & Reference</a>
    </nav>
  
    <div id="content"></div>
  </div>
</body>
</html>

To gather some different IDs just hit the browse categories page and click on some of the different topics. In the new URL you’ll notice a variable appended to the end like ?sid=whatever. That long string of numbers is the unique ID for that category, and we can use that with the API to pull questions recently answered by users.

The PHP Backend

Before we connect into the Ajax/JavaScript let’s create the API data inside a PHP file named ajax.php. The top portion of my script contains a set of static variables which we need for specific API functionality.

$theid = $_POST['catid'];
$cats = array();
$cats['politics']  = "396545444";
$cats['internet']  = "396545660";
$cats['business']  = "396545013";
$cats['science']   = "396545122";
$cats['education'] = "396545015";

$appid = "YOURAPIKEYHERE";
$url = "http://answers.yahooapis.com/AnswersService/V1/getByCategory?appid=".$appid;
 
$apiurl = $url."&category_id=".$theid."&type=resolved&output=json&results=15";

The first variable $theid will be passed into the script from Ajax. This will be a unique category ID which is passed whenever the user clicks on a new category link. Then I’ve also setup an array of these categories so we know which ID number correlates to which category.
Now inside $appid you should replace that string with your own API key. It should be a very long sequence of numbers, letters, and possibly some dashes or other miscellaneous punctuation. The url contains the first piece to our API call along with this key appended onto the string. $apiurl concatenates this along with some new data based on the unique category ID passed in via Ajax.
You can change some of these attributes if you’d like to mess around with different results. However the response type should always be JSON because it’s much easier to manage than XML or direct PHP code.

Looping through Response Data

For the Ajax response to work properly with PHP we need to output all this data into plain HTML format and append this onto the page. You should notice in my index.html file there is a div with the ID #content that is totally empty. This will be our container for all the new data.

$i = 0;
 
// setup our data array
$dataobject = json_decode(file_get_contents($apiurl));

We first create a counter variable $i set to 0. This should be a unique integer which increases every time we loop through a new row of results. This helps us determine odd/even rows so we can apply alternating colors.
Also I’m using the PHP function json_decode() for updating this string of JSON data into an object collection. You’ll notice inside I’m also calling a function file_get_contents() – this is necessary to read the original JSON response from Yahoo!’s remote server. There are other libraries with this same functionality but I find PHP’s default method to be quicker & easier.

// begin output loop
foreach($dataobject->all->questions as $question) {
  $timestamp = $question->Timestamp;
  $dd = date("F d, Y", $timestamp);
  
  echo '<div class="qbox'.(($i = !$i)? ' odd':'').'">'."\r\n";
  echo '<h2><a href="'.$question->Link.'" target="_blank">'.$question->Subject.'</a></h2>'."\r\n";
  echo '<p>Posted '.$dd.' - Total answers: '.$question->NumAnswers.'</p>'."\r\n";
  echo '<p>Link URL: <a href="'.$question->Link.'" target="_blank">'.$question->Link.'</a></p>'."\r\n";
  echo '</div>'."\n\n\n";
 
  $i++;
}

die();

I’m using a really simple foreach() loop to go through the question object and output similar HTML. Each question is contained inside a div with the class .qbox and possibly an alternating class of .odd. The rows are colored with different backgrounds so you can scroll through results much easier. The final die() function is helpful to let Ajax know our script has finished running. It will save response times when calling the same script hundreds of times daily.

Connecting into jQuery/Ajax

Even if you don’t totally follow the PHP code don’t worry! API results are difficult to jump right into, but the concepts are still easy enough if you have time for research. For now let’s examine the final piece to this puzzle which is connecting into JavaScript calls.

$(document).ready(function(){
 
  $("nav a").on("click", function(e){
    e.preventDefault();
  
    var clickid = $(this).attr("id");
    var content = "#content";

I’m first placing an event handler whenever a user clicks any anchor links inside the nav element. We first stop the default href value from loading, then setup a couple variables which point to specific containers on the page.

    if($(this).hasClass("sel")) {
      // do nothing since we already have this selected
    } else {
      // change to display a new content container
      $("a.sel").removeClass("sel");
      $(this).addClass("sel");
   
      $(content).html("<center><img src=\"images/loader.gif\" alt=\"loading...\"></center>");
   
      $.ajax({
        type: "POST",
        url: "ajax.php",
        data: "catid="+clickid,
        dataType: "html",
        success: function(html) {
          $(content).html(html);
        }
      });
    }
  }); // end .on() click event handler
}); // end DOM ready()

If the current link has a class of .sel then we know it’s already been clicked and loaded, so we do nothing. Otherwise the user has clicked a new link and we need to pull new Ajax results.
The selector for $(“a.sel”) will target any other anchor links on the page with a class of .sel. We want to remove these first so that we aren’t running into problems trying to setup this new link as currently being selected. You’ll also notice I’m adding a small loader gif into the content area before we start the Ajax call. This is a small frontend UI piece to update the user and let them know we are, in fact, loading new results.
The final $.ajax() call is fairly straightforward if you’ve ever seen the syntax before. We’re targeting our ajax.php file and passing in the category ID with the variable name used earlier. If the call is successful we get a whole bunch of HTML data returned, and then display this data into the content container. Super simple and nothing too confusing even for beginners!

Live Demo – Download Source Code

Final Thoughts

I hope this tutorial has been educational and also a fun learning experience. You can understand a lot of programming concepts by just playing around with online APIs. Tools and resources you would have never thought about become very helpful in managing web applications.
Feel free to download a copy of my source code and implement something similar on your own website. Yahoo! provides very quick response times and their API is one of the best resources online. The online Y! Answers documentation is plenty helpful for getting yourself started on the path of API development.