Re: connecting php long-polling to the database

On Wed, 2015-02-04 at 22:47 +0300, hadi wrote: > i have script,php-long-polling, im unable to connected to my database. can > someone look to my script and let me know where im wrong. i wanted to > connect to my database and display database table in the html page. > > index.html > > <html> > <head> > <script type="text/javascript" > > src="http://code.jquery.com/jquery.min.js"></script> > <script type="text/javascript" src="client.js"></script> > </head> > <body> > <h1>Response from server:</h1> > <div id="response"></div> > </body> > </html> > server.php > > <?php > > // set php runtime to unlimited > > $servername = "localhost"; > $username = "recorduser"; > $password = "recorduser"; > $database = "record"; > > // Create connection > $conn = mysqli_connect($servername, $username, $password, $database); > // Check connection > if (!$conn) { > die("Connection failed: " . mysqli_connect_error()); > } > > $sql = "SELECT * from username ORDER BY id DESC LIMIT 1"; > $result1 = mysqli_query($conn, $sql); > > set_time_limit(0); > // where does the data come from ? In real world this would be a SQL query > or something > $data_source_file = '$result1'; > // main loop > while (true) { > // if ajax request has send a timestamp, then $last_ajax_call = timestamp, > else $last_ajax_call = null > $last_ajax_call = isset($_GET['timestamp']) ? (int)$_GET['timestamp'] : > null; > // PHP caches file data, like requesting the size of a file, by default. > clearstatcache() clears that cache > clearstatcache(); > // get timestamp of when file has been changed the last time > $last_change_in_data_file = filemtime($data_source_file); > // if no timestamp delivered via ajax or data.txt has been changed SINCE > last ajax timestamp > if ($last_ajax_call == null || $last_change_in_data_file > $last_ajax_call) > { > // get content of data.txt > #$data = file_get_contents($data_source_file); > > $data = while($row = mysqli_fetch_array($result1)) > > { > > echo "<tr>"; > echo "<td>" . $row['name'] . "</td>"; > echo "<td>" . $row['lastname'] . "</td>"; > echo "</tr>"; > } > // put data.txt's content and timestamp of last data.txt change into array > $result = array( > 'data_from_file' => $data, > 'timestamp' => $last_change_in_data_file > ); > // encode to JSON, render the result (for AJAX) > $json = json_encode($result); > echo $json; > // leave this loop step > break; > } else { > // wait for 1 sec (not very sexy as this blocks the PHP/Apache process, > but that's how it goes) > sleep( 1 ); > continue; > } > } > > ?> > client.js > > /** > * AJAX long-polling > * > * 1. sends a request to the server (without a timestamp parameter) > * 2. waits for an answer from server.php (which can take forever) > * 3. if server.php responds (whenever), put data_from_file into #response > * 4. and call the function again > * > * @param timestamp > */ > > function getContent(timestamp) > { > var queryString = {'timestamp' : timestamp}; > > $.ajax( > { > type: 'GET', > url: > 'http://192.168.206.129/record/server.php', > data: queryString, > success: function(data){ > // put result data into "obj" > var obj = jQuery.parseJSON(data); > // put the data_from_file into #response > $('#response').html(obj.data_from_file); > // call the function again, this time with the timestamp we just > got from server.php > getContent(obj.timestamp); > } > } > ); > } > > // initialize jQuery > $(function() { > getContent(); > }); > > What happens when you make a direct request to the PHP script, i.e. not via an AJAX request. What do you see? Are you getting any connection errors, or output? If not, what do your error logs say? -- Thanks, Ash http://www.ashleysheridan.co.uk