YQL Code Examples

Prerequisites

Making YQL Queries with JavaScript

Summary

This code example shows you how to make YQL queries with JavaScript and the OpenSocial function makeRequest. The YQL query in the code example will get data from the GeoPlanet API based on the user's input.

OpenSocial Method: makeRequest

By using the OpenSocial method gadgets.io.makeRequest , you can make calls to a Web service with JavaScript without using a crossdomain.xml file. The calls in this example use 2-legged OAuth authorization.

Before calling the function makeRequest, define the base URI of the YQL Web service, the YQL query, and a callback function to handle the response, as shown below:

To make a call to the YQL Web service, you create a URL-encoded query string with the YQL query and the requested format type of the response and append this query string to the base URI of the YQL Web service. The code snippet below shows the base URI with the appended query string for the YQL Web service. Note that the spaces have been URL-encoded.

This code example has the JavaScript function toQueryString that creates the query string for the call to the YQL Web service as seen below:

By using a closure in the code below, the variable query, which holds the YQL query, is available to makeRequest. The function toQueryString then builds the query string, which is appended to the base URI by makeRequest before making the call to the YQL Web service.

In the code snippet, the function object runQuery is passed the parameters for makeRequest to call the YQL Web service. The handler returns the response data (JSON object) to the OpenSocial function stringify to be converted to a string so it can be displayed in a div tag.

Source Code

<form id="geosearch">
<p><label for="query">Enter Location:</label>
<input id="query" type="text"/></p>
<p><input type="submit" value="Make Query"/></p>
</form>
<div id="results"></div>

var BASE_URI = 'http://query.yahooapis.com/v1/yql';

// function calling the opensocial makerequest method
  function runQuery(query, handler) {
    gadgets.io.makeRequest(BASE_URI, handler, {
        METHOD: 'POST',
        POST_DATA: toQueryString({q: query, format: 'json'}),
        CONTENT_TYPE: 'JSON',
        AUTHORIZATION: 'OAuth'
    });
  };
  
  // Tool function to create a request string
  function toQueryString(obj) {
    var parts = [];
    for(var each in obj) if (obj.hasOwnProperty(each)) {
      parts.push(encodeURIComponent(each) + '=' +
                 encodeURIComponent(obj[each]));
    }
    return parts.join('&');
  };
  
  // Run YQL query to GeoPlanet API and extract data from response  
  runQuery('select * from geo.places where text="' + location + '"',
    function(rsp) {
      if(rsp.data){
        var place = rsp.data.query.results.place;
        if(place[0]){
          place = place[0];
        }
        var name      = place.name || 'Unknown';
        var country   = place.country.content || place[0].country.content ||
                        'Unknown';
        var latitude  = place.centroid.latitude || 'Unknown';
        var longitude = place.centroid.longitude || 'Unknown';
        var city      = place.locality1.content || 'Unknown';
        var state     = place.admin1.content || 'Unknown';
        var county    = place.admin2.content || 'Unknown';
        var zip       = place.postal ? place.postal.content : 'Unknown';
  
        content = '<ul><li><strong>Place Name: </strong>' + name + '</li>'+
        '<li><strong>City/Town: </strong>' + city + '</li>' +
        '<li><strong>County/District: </strong>' + county + '</li>' +
        '<li><strong>State/Province: </strong>' + state + '</li>' +
        '<li><strong>Zipcode: </strong>' + zip + '</li>' +
        '<li><strong>Country: </strong>' + country + '</li>' +
        '<li><strong>Latitude: </strong>' + latitude + '</li>' +
        '<li><strong>Longitude: </strong>' + longitude + '</li></ul>';
        container.innerHTML = content;
      }
      else {
        container.innerHTML = gadgets.json.stringify(rsp);
      }
  });
}
// Create an event handler for submitting the form
var form = document.getElementById('geosearch');
form.addEventListener('submit',makeQuery,false);
</script>

Making YQL Queries with PHP

Summary

This example, yql_php.php, is a simple application that uses cURL to make YQL calls to the Upcoming API.

To understand the following material, you should already be familiar with the topics covered in the Two-Minute Tutorial.

Building the YQL URL

To build the YQL URL, append the YQL query to the base URL of the YQL Web service.

First, assign the base URL of the YQL Web service to a variable.

$yql_base_url = "http://query.yahooapis.com/v1/public/yql";
Now create the YQL query to the Upcoming API and append it to the YQL base URL. YQL queries are passed as query strings, so they must be URL encoded. The query string must begin with q=.

$yql_query = "select * from upcoming.events where location='San Francisco' and search_text='dance'"; $yql_query_url = $yql_base_url . "?q=" . urlencode($yql_query);
The YQL Web service returns XML as the default format. This code example requests JSON by appending the name-value pair format=json to the query string as shown.

$yql_query_url .= "&format=json";
Run the query in the YQL console and look at both the URL in The REST query window and the JSON response in the Formatted View window.

Calling the YQL Web Service with cURL

Calling the YQL Web service with cURL only requires three lines of code. After initializing the call by passing the curl the YQL URL, you request a response with curl_setopt and then execute the call.

To make the response easier to handle, convert the JSON response to a PHP object to easily access data.

Parsing the Response

The YQL Web service will always return results wrapped in the query field with meta data. If the YQL query returns data, the data is wrapped in the results field, which you can see by running this query.

If no data is returned, the results element in the XML response is empty or the results field in JSON is null. Therefore, before parsing the response returned by YQL, your code should always check the results field as shown below:

The structure of the data within the results field that is returned by YQL is different for each API. The repeated field (like a row in an SQL table) in the returned response in this code example is the event field. The code below extracts and displays data from each event:

Source Code

<h2>Using YQL to Access the Upcoming API</h2>
<form name='upcoming_form'>
Location: <input name='location' id='location' type='text' size='20'/><br/>
Event: &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<input name='event' id='event' type='text' size='20'/><br/>
<p><button id='find_event'>Find Event</button></p>
</form>

if(isset($_GET['event']) && isset($_GET['location'])){
    $location = $_GET['location'];
    $query = $_GET['event'];
    $events="";
     
    // Form YQL query and build URI to YQL Web service
    $yql_query = "select * from upcoming.events where location='$location' and search_text='$query'";
    $yql_query_url = $BASE_URL . "?q=" . urlencode($yql_query) . "&format=json";

// Make call with cURL
    $session = curl_init($yql_query_url);
    curl_setopt($session, CURLOPT_RETURNTRANSFER,true);
    $json = curl_exec($session);
    // Convert JSON to PHP object 
    $phpObj =  json_decode($json);

// Confirm that results were returned before parsing
    if(!is_null($phpObj->query->results)){
      // Parse results and extract data to display
      foreach($phpObj->query->results->event as $event){
        $events .= "<div><h2>" . $event->name . "</h2><p>";
        $events .= html_entity_decode(wordwrap($event->description, 80, "<br/>"));
        $events .="</p><br/>$event->venue_name<br/>$event->venue_address<br/>";
        $events .="$event->venue_city, $event->venue_state_name";
        $events .="<p><a href=$event->ticket_url>Buy Tickets</a></p></div>";
      }
    }
    // No results were returned
    if(empty($events)){
      $events = "Sorry, no events matching $query in $location";
    }
    // Display results and unset the global array $_GET
    echo $events;
    unset($_GET);
  }
?>

YQL Social Application

Summary

This example, yql_basic.php, is a simple application that uses the Yahoo! Social SDK for PHP to make YQL calls. Using YQL with the SDK is ideal because the SDK will handle your OAuth authorization, which is required to access the Social Directory APIs. YQL, in turn, extends the functionality of the SDK by enabling access to the public data from Yahoo! Web services and external data such as RSS and Atom feeds.

To understand the following material, you should already be familiar with the topics covered in My Social PHP Application and the Two-Minute Tutorial.

Initial Code

Before proceeding with the code that makes YQL queries, be sure to include the PHP SDK and define an API Key and a Shared Secret:

Querying Public Data

There are great number of sources for public data on the Web that can be accessed with YQL. Although public, many of these sources require authorization. With the API Key and the Shared Secret provided by Yahoo!, you can use the PHP SDK to perform two-legged authorization with the YahooApplication class. (If you need to read up on two-legged authorization, see Private Data v. Public Data.) From a YahooApplication object, invoke the method query, which calls the YQL Web service (that is, runs the YQL queries). The following code snippets show you how to perform two-legged authorization with YahooApplication and how to make YQL queries.

The API Key and Shared Secret are passed to the constructor of the YahooApplication class. If the application has been authorized by Yahoo!, the YahooApplication object $two_legged_app is returned:

Next, the application defines two YQL queries: one to the Flickr API, another to the Yahoo! News RSS feed. You can also run these queries in the YQL Console:

With the $two_legged_app object, the application calls the query method. The var_dump shows the structure and contents of the query response of the YQL Web service:

Querying Private Data

Unlike YQL queries for public data, you need user authorization to obtain data from the Social Directory APIs (Profiles, Updates, Connection, Contacts, and Presence). During the process of user authorization, the user will be redirected to the Yahoo! login page and then asked to authorize your application. You initiate this three-legged authorization process with the YahooSession class. (If you are unfamiliar with the term "three-legged authorization," you may want to read Private Data v. Public Data.) Getting a valid YahooSession object means that the user has authorized your application, allowing you to access this user's private data. The following code snippets show how to perform authorization with YahooSession and how to use YQL to access private social data from Yahoo!

The method requireSession makes sure the user has logged into Yahoo!, redirecting to the Yahoo! login page if necessary. A YahooSession object is returned, confirming that the OAuth authorization has been completed:

The YQL queries and API names are assigned to the associative array $api_queries:

The YQL query is made from the YahooSession object $session with the method query. The use of var_dump allows you to see the contents of the returned response for each YQL query:

The following listing shows the var_dump from the YQL query made on the Profiles API.

Profiles Data

array(1) {
  ["query"]=>
  array(7) {
    ["count"]=>
    string(1) "1"
    ["created"]=>

string(20) "2008-10-08T06:11:21Z"
    ["lang"]=>
    string(5) "en-US"
    ["updated"]=>
    string(20) "2008-10-08T06:11:21Z"
    ["uri"]=>
    string(80) "http://query.yahooapis.com/v1/yql?q=select+*+from+social.profile+where+guid%3Dme"
    ["diagnostics"]=>
    array(4) {
      ["url"]=>
      array(2) {
        ["execution-time"]=>
        string(1) "9"
        ["content"]=>
        string(89) "http://social.yahooapis.com/v1/users.guid(UQIDZJNWVNLQD4GXZ5NGMZUSTQ4)/profile"
      }
      ["user-time"]=>
      string(2) "11"
      ["service-time"]=>
      string(1) "9"
      ["build-version"]=>
      string(16) "2008.10.06.06:05"
    }
    ["results"]=>
    array(1) {
      ["profile"]=>
      array(16) {
        ["xmlns"]=>
        string(41) "http://social.yahooapis.com/v1/schema.rng"
        ["yahoo"]=>
        string(36) "http://www.yahooapis.com/v1/base.rng"
        ["uri"]=>
        string(70) "http://social.yahooapis.com/v1/user/UQIDWJJWVNQD4GXZ5NGMZUSTQ4/profile"
        ["guid"]=>
        string(26) "UQIDWJNWVNQD4GXZ5NGMZUSTQ4"
        ["created"]=>
        string(20) "2008-09-16T05:06:29Z"
        ["familyName"]=>
        string(2) "Me"
        ["gender"]=>
        string(1) "M"
        ["givenName"]=>
        string(2) "Me"
        ["image"]=>
        array(4) {
          ["height"]=>
          string(3) "192"
          ["imageUrl"]=>
          string(102) "http://F3.yahoofs.com/coreid/401ebcc8bi12ezoul3sp1/tCdOLz0rc6luV96s.2tNESY-/1/t192.jpg?ciAIxOJB_GvKUNDs"
          ["size"]=>
          string(7) "192x192"
          ["width"]=>
          string(3) "192"
        }
        ["interests"]=>
        array(2) {
          ["declaredInterests"]=>
          string(13) "Cloud bathing"
          ["interestCategory"]=>
          string(13) "prfFavHobbies"
        }
        ["lang"]=>
        string(5) "en-US"
        ["location"]=>
        string(17) "San Francisco, CA"
        ["nickname"]=>
        string(11) "blisterHead"
        ["profileUrl"]=>
        string(54) "http://profiles.yahoo.com/u/UQIDWJNWIQ7NQD4GXZ5NGMZUSTQ4"
        ["timeZone"]=>
        string(19) "America/Los_Angeles"
        ["isConnected"]=>
        string(4) "true"
      }
    }
  }
}

Source Code

<?php
// Include the PHP SDK for YSP library.
include_once("yosdk/lib/Yahoo.inc");

// Define constants to store your API Key (Consumer Key) and
// Shared Secret (Consumer Secret).
define("API_KEY","your_Consumer_Key_goes_here");
define("SHARED_SECRET","your_Shared_Secret_goes_here");

// The YahooApplication class is used for two-legged authorization, 
// which doesn't need permission from the end user.
$two_legged_app = new YahooApplication(API_KEY,SHARED_SECRET);
if ($two_legged_app == NULL) {
   // Print error message and and then exit the script.
   print ("<br />");
   print ("Error: Cannot get two_legged_app (YahooApplication object)."); 
   exit;
}

// Define queries for Flickr and an RSS news feed
$flickr_query = 
  "select * from flickr.photos.search where text=\"panda\" limit 3";
$news_feed = 
  "select * from rss where url='http://rss.news.yahoo.com/rss/topstories' and title LIKE \"%China%\"";

// Call the query and dump the response.
echo "<h2>Flickr Data</h2>";
$flickrResponse = $two_legged_app->query($flickr_query);
echo "<pre>";
var_dump($flickrResponse);
echo "</pre>";

echo "<h2>RSS Data</h2>";
$newsResponse = $two_legged_app->query($news_feed);
echo "<pre>";
var_dump($newsResponse);
echo "</pre>";

if (($flickrResponse==NULL) OR ($newsResponse==NULL)) {
   print ("<p>");
   print ("Warning: flickrResponse or newsResponse is NULL."); 
   print ("Check your API Key (Consumer Key) and Shared Secret (Consumer Secret)");
   print (" Also, make sure your query is valid.");
   print ("</p>");
}

// The YahooSession class is used for three-legged authorization,
// which does require permission from the end user.

$session=YahooSession::requireSession(API_KEY, SHARED_SECRET);
if ($session == NULL) {
   // Print error message and and then exit the script.
   print ("<p>");
   print ("Error: Cannot get session object."); 
   print (" Check your API Key (Consumer Key) and Shared Secret (Consumer Secret)");
   print ("</p>");
   exit;
}

// Define YQL queries for the Social Directory APIs
$profile = "select * from social.profile where guid=me";
$contacts = "select fields.value from social.contacts where guid=me";
$connections = "select * from social.connections where owner_guid=me";
$updates = "select * from social.updates where guid=me";
$status = "select value.status from social.presence where guid=me";

$api_queries = array("Profiles"=>$profile,
   "Contacts"=>$contacts,
   "Connections"=>$connections,
   "Updates"=>$updates,
   "Presence"=>$status);

// Make the calls to YQL and dump the responses.
foreach($api_queries as $api=>$query) {
   echo "<h2>$api Data</h2>";
   $queryResponse = $session->query($query);
   if ($queryResponse == NULL) {
      echo "<p>";
      echo "Error: No query response for $api.";
      echo " Check your permissions. Also, check the syntax of the YQL query.";
      echo "</p>";
   }
   else {
      echo "<pre>";
      var_dump($queryResponse);
      echo "</pre>";
   }
}
?>

YQL INSERT: WordPress Open Application

Summary

This code example shows how to use the YQL INSERT statement in an Open Application to post to your WordPress blog. YML is used to create a simple HTML form for the UI, and PHP is used to call the YQL Web service to run the YQL INSERT statement.

Prerequisites

Small View: yml:form

The WordPress Open Application uses the YML tag yml:form for entering information. The attribute params is like the HTML form attribute action. In the code snippet below, the user triggers the call to the script yql_insert_wordpress.php when submitting the form by clicking "Publish".

The attribute insert places the returned response from yql_insert_wordpress.php into the div tag "blog_sect". If "Publish" is clicked again, the contents in this div will be replaced with the new content returned by yql_insert_wordpress.php.

YQL: INSERT

The syntax for the YQL INSERT statement follows that of the SQL INSERT statement:

INSERT INTO (table) (list of comma separated field names) VALUES (list of comma separated values)

Try running the following YQL INSERT statement that references the WordPress Open Table and then view the results at http://yqlblog.wordpress.com .

USE 'http://www.datatables.org/wordpress/wordpress.post.xml' AS wordpress.post; INSERT INTO wordpress.post(title, description, blogurl, username, password) VALUES ("YQL meets WordPress", "Posting with YQL", "http://yqlblog.wordpress.com", "yqlblog", "password")

Calling the YQL Web Service

Building the URL

The URL for making a request to the YQL Web service has a base URL and a query string. The query string contains the YQL statement, the requested response format, and any environment files. The environment file at http://datatables.org/alltables.env includes the USE statement for the WordPress Table, which creates the alias wordpress.post as seen below:

use 'http://www.datatables.org/wordpress/wordpress.post.xml' as wordpress.post;

Below, the URL used to call the YQL Web service is divided and stored in variables to illustrate the different components: $yql_base_url holds the base URL to the YQL Web service, $yql_insert holds the YQL INSERT statement, and $yql_format and $yql_env_tables hold the request format and URL to the environment file respectively.

Because the YQL INSERT statement is sent via POST with cURL, we build the POST fields by concatenating the various components. We configure the cURL call to send the POST fields in Calling the YQL Web Service. Notice that in this code snippet only $yql_format is not URL-encoded because it contains the characters '&' and '='.

Sending the Request to YQL

Before making the request with cURL, let's look again at the variables that hold the base URL and the post fields from Building the URL:

The cURL call for this code example is fairly typical. You need to configure cURL to send the request via POST and accept POST fields, ask for a returned response, and turn off SSL verification for both host and peer certificates:

Source Code

Small View Code

WordPress Open Application

<?php
  
  // Include Y!OS PHP SDK to create Small view
  // Be sure to enter your Consumer Key (API Key) and Shared Secret 
  include_once("path_to_SDK/yosdk/lib/Yahoo.inc");
  define('CONSUMER_KEY',"place_your_consumer_key_here");
  define('SHARED_SECRET', "place_your_shared_secret_here");

// Assign YML code for small view to variable
  $yml = "<yml:user-badge uid=\"viewer\" linked=\"true\" width=\"55\" reflexive=\"false\" useyou=\"false\" capitalize=\"true\" />" .
         "<yml:form name=\"wordpress\" params=\"add_blog.php\"  method=\"POST\" insert=\"blog_sect\">" .
         "<fieldset><b>Username:</b> <input type=\"text\" name=\"username\"/><br/>" .
         "<b>Password:</b> <input type=\"password\" name=\"password\" /> <br/>" .
         "<b>Blog URL:</b> <input type=\"text\" name=\"blogurl\" /> <br/>" .
         "<input type=\"hidden\" name=\"blog_form\"/><p>" .
         "<b>Title:</b> <input type=\"text\" name=\"title\"/></p>" .
         "<p><b>Add New Post:</b> <br/>" .
         "<textarea name=\"blog\" rows=\"5\" cols=\"40\">Enter your blog post here.</textarea><br/>" .
         "</p><input type=\"submit\" name=\"submit\" value=\"Publish\" />" .
         "</fieldset></yml:form><div id=\"blog_sect\"></div>";
  
   // Authenticate app and create session: you need to do this to set Small view w/ SDK
  $yahoo_session = YahooSession::requireSession(CONSUMER_KEY, SHARED_SECRET);  
  $yahoo_user = $yahoo_session->getSessionedUser();  
  
  // Output blog form if it has been created yet 
  if(!isset($_POST['blog_form'])){
    // Display YML form either in the Full or Small view
    if(!strcmp($_POST['yap_view'],"YahooFullView")){
      echo $yml;
    }else {
       $yahoo_user->setSmallView($yml);
    }
  } else {
     // Form has already been loaded: check for errors (missing fields)
     $errors = array();
     if(empty($_POST['username'])){
       $errors[] = "No username";
     } else { 
         $username = $_POST['username'];
     }
     if(empty($_POST['password'])){
       $errors[] = "No password";
     } else{
         $password = $_POST['password'];
     }
     if(empty($_POST['blog'])){
       $errors[] = "No blog text";
     } else {
         $blog = $_POST['blog'];
     }
     if(empty($_POST['blogurl'])){
       $errors[]= "No blog URL";
     }else{
       $blogurl = stripos($_POST['blogurl'],'http')==0 ? $_POST['blogurl'] : 'http://' . $_POST['blogurl'];
     }
     // If there are errors, display error messages
     if(count($errors)>0){
       print("You have the following errors: <br/><span style='color: red'><ul>");
       foreach($errors as $error){
          print("<li>$error</li>");
       }
      print("</ul></span>");
     } else{
       // No errors: make calls to YQL to run INSERT and SELECT statements
     	 $title = empty($_POST['title']) ? "Unknown" : $_POST['title'];
       // Base URL to the YQL Web service
     	 $yql_url = 'https://query.yahooapis.com/v1/public/yql';
       // YQL INSERT statement w/ blog data required by WordPress Open Data Table
     	 $yql_insert = "INSERT INTO wordpress.post(title,description,blogurl,username,password) " .
     	              "VALUES(\"$title\",\"$blog\",\"$blogurl\",\"$username\",\"$password\")";
       // Request XML and use the global env for all available Open Data Tables
       $yql_format = "&format=xml&env=";
       $yql_env = "http://datatables.org/alltables.env";

// Begin cURL call to YQL w/ POST fields and a returned response 
     	 $ch = curl_init($yql_url);
     	 curl_setopt($ch, CURLOPT_POST, 1);
     	 curl_setopt($ch, CURLOPT_POSTFIELDS, "q=" . rawurlencode($yql_insert) . $yql_format . rawurlencode($yql_env));
     	 curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);  
     	 curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
     	 curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
       // Execute request, receive response, and close cURL handle
     	 $x = curl_exec($ch);
       curl_close($ch);
       // Parse returned responses into SimpleXMLElement object to determine if call was successful and to get the post ID
     	 $s = simplexml_load_string($x);
     }
     // Make a YQL SELECT statement if INSERT statement was successful
     // both to illustrate the SELECT statement and to obtain data about the blog posting 
     if($s->results->postid){
       // The post ID is necessary to make the YQL SELECT statement
       $postid = $s->results->postid;
       // Form the YQL SELECT statement
       $yql_select = "SELECT * FROM wordpress.post WHERE postid=\"$postid\" AND username=\"$username\"";
       $yql_select .= " and password=\"$password\" and blogurl=\"$blogurl\"";
       // Begin cURL process to make call to YQL Web service; the POST field is the YQL SELECT statement; ask for a return 
       $ch2 = curl_init($yql_url);
     	 curl_setopt($ch2, CURLOPT_POST, 1);
     	 curl_setopt($ch2, CURLOPT_POSTFIELDS, "q=" . rawurlencode($yql_select) . $yql_format . rawurlencode($yql_env));
     	 curl_setopt($ch2, CURLOPT_RETURNTRANSFER, 1);  
     	 curl_setopt($ch2, CURLOPT_SSL_VERIFYPEER, false);
     	 curl_setopt($ch2, CURLOPT_SSL_VERIFYHOST, false);
     	 $x2 = curl_exec($ch2);
       curl_close($ch2);
       // Parse response into SimpleXMLElement object to extract data about blog
     	 $s2 = simplexml_load_string($x2);
       if(!is_null($s2)){
       ?><div style='background-color: #CCCCFF; color: #000033; padding: 5px;'><?
         if($s2->xpath('//member')){
           foreach($s2->xpath('//member') as $member)
           { 
             // Obtain the date, user, title, blog text, and link to blog
             if(!strcmp($member->name[0],"dateCreated")){
               $date = $member->value->string ? $emember->value->string : strftime('%c',strtotime('now'));
             }elseif(!strcmp($member->name[0],"userid")){
               $user = $member->value-string ? $member->value->string : $username;
             }elseif(!strcmp($member->name[0],"title")){
               $title = $member->value->string;
             }elseif(!strcmp($member->name[0],"description")){
               $blog_post = $member->value->string;
             }elseif(!strcmp($member->name[0],"link")){
               $link = $member->value->string;
            }
          }
        }
        ?>
        <p><em>Blog posted successfully by YQL INSERT!</em></p><b>Blog Metadata:</b><ul style='border: blue solid 1px; padding: 20px; width: 300px; background-color: #CCFFFF;'>
        <?php
        // Display blog data in div tag and blog text in text area
        echo "<li><b>Date Created:</b> $date</li><li><b>Posted By:</b> $user</li><li><b>Title:</b> $title</li>";
        echo "<li><b>Link to Blog:</b> <a href=\"$link\">$link</a></li></ul>";
        echo "<b>Blog Text:</b></p><br/>";
        echo "<textarea rows='5' cols='40' readonly='true'>$blog_post</textarea>";
        ?></div>
       <?  
        }else{
         // YQL SELECT statement failed; output error message.
          echo "Sorry, we could not display your blog data or blog text.";
         }
      } else {
         // YQL INSERT statement failed; output error message
         echo '<p>Sorry, your blog was not updated. :-(</p>';
     }
     unset($_POST);
  }
?>

Getting Updates with YQL

Summary

This code example shows you how to use YQL with the Yahoo! Social SDK for PHP to get user updates and the updates for the user's connections. The SDK handles the OAuth authorization, and YQL fetches the user data.

To understand the following material, you should already be familiar with the topics covered in My Social PHP Application and the Two-Minute Tutorial.

Prerequisites

YQL Queries

The syntax of YQL is similar to that of SQL, and the YQL Web service, like a MySQL database, returns data based on queries. The YQL Web service, however, returns the data in the form of XML or JSON. For more information about making YQL queries, see SELECT Statement.

YQL has a special literal me that holds the GUID of the currently logged in Yahoo! user. This YQL query uses this special literal to get the data of five connections of the currently logged in Yahoo! user.

SELECT * FROM social.connections WHERE owner_guid=me LIMIT 5

From the YQL response for the query above, you can then extract the GUID for each connection. These GUIDs can then be matched against the key guid in a new YQL query to get the updates for each connection as shown in the code snippet below:

SELECT * FROM social.updates WHERE guid='GUID_of_a_connection' LIMIT 5

Now that you have some familiarity with YQL and its syntax, try using the YQL Console to experiment with different YQL queries and different tables such as Flickr and Search.

Calling the YQL Web Service with the PHP SDK

The code example uses the method requireSession from the class YahooSession to get authorization to access user data and the method query to call the YQL Web service. The code snippets below will focus on authorization and YQL queries.

This one line of code does a lot of work to complete the OAuth authorization. The method requireSession first looks for an existing session, and if it's not found, redirects the user to the Yahoo! login page to sign in. The user can then authorize the app to access private data. The return value of requireSession is a YahooSession object (a session), which you will use next to make YQL queries.

To call the YQL Web service, pass the YQL query to the method query from the YahooSession object $session. In the code snippet below, the results of the queries are passed to the variables $user_updates and $user_connections to be parsed for specific data.

Source Code

<?php
/**
This example demonstrates how to use the PHP SDK for YSP 
with YQL to get user updates and the updates of user connections.
*/ 
    
// Include the YOS library.
// Be sure that the path to the PHP SDK is correct before running
// code example.
require("path_to_PHP_SDK/yosdk/lib/Yahoo.inc");

// Display all errors for debugging
ini_set('display_errors',1);
error_reporting(E_ALL);

// Store error messages
$failed_session = "Your application could not be authorized. " .
                  "Please check the following:<br/>" .
                  "<ul><li>Your OAuth keys are correct</li>" .
                  "<li>The path to the PHP SDK is correct</li></ul>" .
                  "<p>If your keys and the path to the PHP SDK are " .
                  "correct, there might have been a server error " .
                  "during authorization.<br/>" .
                  "Please try running your app again.</p>";
$failed_query_updates = "The call to the YQL Web service to get user updates failed.";
$failed_query_conns = "The call to the YQL Web service to get user connections failed.";
$no_user_updates = "There are no user updates.";
$no_user_conns = "The user has no connections.";

// Get Consumer Key and Shared Secret (Consumer Secret)
// by creating a new Open Application from My Projects at
// http://developer.yahoo.com/dashboard/.

// Define your Consumer Key
$consumerKey =  "put_your_consumer_key_here";

// Define your Consumer Secret (Shared Secret)
$consumerSecret = "put_your_consumer_secret_here";

// Authorize the app to get user data.
$session = YahooSession::requireSession($consumerKey, $consumerSecret);

// Display error message if the app was not able to be authorized.
if(!$session)
{
   die($failed_session); 
}

// Use the SDK method 'query' from the YahooSession class 
// Limit the results to 5 updates and 5 connections
$user_updates = $session->query("SELECT * FROM social.updates WHERE guid=me LIMIT 5");

// Display error message if the YQL query to get the user's updates fails.
if(!$user_updates)
{
  die($failed_query_updates);
}

// Display message if user has no updates, but do
// not exit program as user might have connections
else if($user_updates->query->count==0)
{
  print("<p>".$no_user_updates."</p>");
}

// Display error message if the YQL query to get the user's connections fails.
$user_connections = $session->query("SELECT * FROM social.connections WHERE owner_guid=me LIMIT 5");
if(!$user_connections)
{
  die($failed_query_conns);
}

// Display message and exit as app's work is done
// if user has no connections
else if($user_connections->query->count==0)
{
  die($no_user_connections);
}

// First extract update info for the user
// and display the profile image as well as
// links to the user profile and each update.
foreach($user_updates as $results)
{
  echo "<p/>";
  $name_displayed = false;
  for($i=0;$i<5;$i++)
  {
    $title = $results->results->update[$i]->title;
    $name = $results->results->update[$i]->profile_nickname;
    $url = $results->results->update[$i]->itemurl;
    $profile = "http://profiles.yahoo.com/u/" . $results->results->update[$i]->profile_guid;
    $profile_img = $results->results->update[$i]->profile_displayImage;
    if(!$name_displayed){ 
      echo "<img src='$profile_img' height='50' width='50' align='absmiddle'/>";
      echo "<b>Your Updates (<a href='$profile'>$name</a>)</b>";
      echo "<br/><ul>";
      $name_displayed = true; 
    }                 
    if(strpos($title,$name)===false)
    {
       echo "<li><a href='$url'>$name $title</a></li>";
    }
    else
    {
      echo "<li><a href='$url'>$title</a></li>";
    }
  }
  echo "</ul><hr />";
}

// Now extract update info for user connections,
// displaying the profile image and links to
// the profile and to each update. 
$connections_results = $user_connections->query->results;
foreach($connections_results->connection as $connection)
{
  $updates = $session->query("select * from social.updates where guid='$connection->guid' limit 5");
  // Display message if connection has no updatees and go to
  // next connection.
  if($updates->query->count==0)
  {
    echo "<p>The user has no updates</p>";
    continue;  
  }
  foreach($updates as $results)
  {
    $name_displayed = false;
    for($i=0;$i<5;$i++)
    {
      $title = $results->results->update[$i]->title;
      $name = $results->results->update[$i]->profile_nickname;
      $url = $results->results->update[$i]->link;
      $profile = "http://profiles.yahoo.com/u/" . $results->results->update[$i]->profile_guid;
      $profile_img = $results->results->update[$i]->profile_displayImage;
      if(!$name_displayed){
       echo "<img src='$profile_img' height='50' width='50' align='absmiddle'/>";
       echo "<b>Updates for <a href='$profile'>$name</a></b>";
       echo "<br/><ul>";
       $name_displayed = true;
      }
      if(strpos($title,$name)===false)
      {
        echo "<li><a href='$url'>$name $title</a></li>";
      }
      else
      {
        echo "<li><a href='$url'>$title</a></li>";
      }
   }
    echo "</ul><hr />";
  }
}
?>

Data Scraping with YQL

Summary

This example, yql_html_scraper.html, uses YQL to scrape HTML from Yahoo! News and then creates customized output. The YQL module for YUI is used to call the YQL Web service.

Using the YQL Module for YUI

You can can download the YQL module for YUI from GitHub or include it in your Web page like any other JavaScript file. The steps below will show you how to use the YQL module to call the YQL Web service.

Include the YUI library, which includes the YQL module, in your Web page.

<<script src="http://yui.yahooapis.com/3.8.0/build/yui/yui-min.js"></script>
Create a YUI instance to load the Node and YQL modules.

YUI().use('node', 'event', 'yql, function(Y) { // The code for manipulating DOM, handling events, // calling the YQL Web service, and parsing // the response goes here. })
Using the html table, create a YQL query to get data from Yahoo! News. See Using XPath in YQL Statements for details about the YQL query.

var yql_query = "select * from html where url='" + news_url + story + "'"; yql_query += " and xpath='//div[@class=\"content\"]//div[@class=\"txt\"]/p'";
Instantiate a YQL object by passing the YQL query and a callback function to Y.YQL.

Y.YQL(yql_query, function(response) { ... } );
To initiate the call to the YQL Web service, add an event handler to a click event that will call the YQL.

Y.one("#get_stories").on('click', function() { ... Y.YQL(yql_query, function(response) { ... }); });
Make sure that results were returned and then parse those results.

var stories = "<div><ul>"; if(response.query.results){ var no_stories = response.query.results.p.length; var paras = response.query.results.p; paras.forEach(function(node,index) { if (node.hasOwnProperty('a') && node.hasOwnProperty('content')) { stories += "<li><a href='" + news_url + node.a.href + "' title='" + node.a.title + "'>" + node.content + "</a></li>"; } }); } else{ stories += "<li>Sorry, could not find any headlines for the category " + story + ". Please try another one.</li>"; } stories += "</ul></div>";

Because each a element is a seen as row of data by YQL, you need to iterate through each a element to access the href and content child elements. Run the query in the YQL Console to examine the data structure or the returned response in greater detail.

Using XPath in YQL Statements

The YQL statement below is used in this code example to access the links for stories from Yahoo! News. This section will examine the data source for the YQL statement and the XPath expression that extracts the links.

select * from html where url='http://news.yahoo.com/{category}' and xpath='//div[@class="content"]//div[@class="txt"]/p'

The YQL query in this example allows you to access HTML using the html table. YQL also has tables for accessing other data formats, such as XML, CSV, JSON, RSS, XST, etc.

select * from html

The key url determines the data source for the YQL query. The data source in this example is World News page on Yahoo! News.

url='http://news.yahoo.com/world'

The XPath statement below extracts the <p> elements from <div> element with the class txt. Each paragraph (p element) is returned as a row (repeated element in XML).

xpath='//div[@class="content"]//div[@class="txt"]/p'

For more information about XPath, see WC3 XPath Language.

Source Code

<b>Stories: </b> <input type='text' size='15' id='story' value='world'/><br/><br/>
<button id='get_stories'>Get Stories</button>
<div id='results'></div>
<script src="http://yui.yahooapis.com/3.8.0/build/yui/yui-min.js"></script>
<script>
// Calls YQL Web service, parses results, and outputs results
YUI().use('node', 'event', 'yql', function(Y) {
  Y.one("#get_stories").on('click',function() {
    var stories = "<div><ul>";
    var story = Y.one('#story').get('value') || 'world';
    var news_url = "http://news.yahoo.com/";
    var yql_query = "select * from html where url='" + news_url + story + "'";
    yql_query += " and xpath='//div[@class=\"content\"]//div[@class=\"txt\"]/p'";
    Y.YQL(yql_query, function(response) {
      if(response.query.results){
        var no_stories = response.query.results.p.length;
        var paras = response.query.results.p;
        paras.forEach(function(node,index) {
          if (node.hasOwnProperty('a') && node.hasOwnProperty('content')) {
            stories += "<li><a href='" + news_url + node.a.href + "' title='" + node.a.title + "'>" + node.content + "</a></li>";
          }
       });
      } else{
        stories += "Sorry, could not find any headlines for the category " + story + ". Please try another one.";
      }
      stories += "</ul></div>";
      Y.one('#results').append(stories);
      stories = "";
    });
  }); 
});       
</script>

Yahoo! Query Language