Need a way to give updates while script processes

[JasonHenry]

Hi. I am working on a backend for a simple flash arcade site as a php learning experience. I have written a script and am trying to figure out a way to give updates while the script runs.

1)It downloads a JSON feed which can reach 30 Mb and saves it locally
2)Parses the data from the local file and populates it to a db table

I have tried various things with flushing the output buffer, but I don't think I have a good enough grasp on the concept. Just looking for any suggestions as to the methods to accomplish this. The file downloading is via curl. I'm still fuzzy how javascript affects php as the server parses the whole script first as I understand.

Thanks!

[hash]

flush() will send data to the browser, but I believe there can be issues with the server's buffer, and on top of that, there are issues with the browser's buffer. In FF, flush() is enough, I've tested the following in FF and Chrome, both work on my setup.

echo str_repeat(" ", 1024); // needed for chrome, I think IE is 256
flush();
for($x=0; $x<5; $x++)
{
    sleep(1);
    echo 'working ...<br>'; // <br> needed for chrome, \n might be needed for some browsers
    flush();
} 

[JasonHenry]

Thanks for the input hash. I tried your code on my apache server/windows machine and server host's linux box and it didn't flush the output until the script was finished running. (FF) I put this code in a section of code which downloads a SWF and PNG image from a server and writes to local files. The text did not appear until the actions were finished...then output the 5 "working..." strings. I do not have a good working knowledge yet of the these deeper php functions and methods. Seen a lot of talk about the flush() function in various how-to's but I guess I just haven't seen any magic yet.

What is the purpose of echoing the spaces? Is it for formatting or some affect on the buffer?

[hash]

Weird that it didn't work in FF, I can only assume this is because of the server config. All I need is the for loop for FF (on both win and linux).

The spaces are to fill up the browsers buffer. Once full it will output to the screen. Took 1024 bytes for Chrome.

[JasonHenry]

Could the file operations make a difference?

Here is a function I put your code into. Perhaps I am not doing it correctly.

function install_mochigame($gameid) {
    $result = yas_query("SELECT * FROM `mochigames` WHERE `id` = '$gameid'");
    $gamename = $result[1];
    $thumburl = $result[7];
    $gameurl = $result[2];
    echo str_repeat(" ", 1024); // needed for chrome, I think IE is 256
    flush();
    for($x=0; $x<5; $x++)
    {
        sleep(1);
        echo 'working ...<br>'; // <br> needed for chrome, \n might be needed for some browsers
        flush();
    } 
    
    set_time_limit(0);       
    $fileurl = str_replace("..", "", $thumburl);    // Download thumbnail
    $thumb = get_content_of_url($fileurl);    // uses cURL functions to get file
        
    $fileurl = str_replace("..", "", $gameurl);
    $swf = get_content_of_url($fileurl);            // Download game file  
        
    $fconfig = fopen("../img/" . $gamename . ".png", 'wb');  // Save thumbnail
    fwrite($fconfig, $thumb);
    fclose($fconfig);
    empty($thumb);
    
    $fconfig = fopen("../swf/" . $gamename . ".swf", 'wb');    // Save game file
    fwrite($fconfig, $swf);
    fclose($fconfig);
    empty($swf);
            
    $gamefile = 'swf/' . $gamename . '.swf';
    $gamethumb = 'img/' . $gamename . '.png';  
    $category = explode(",", $result[8]);       // Remove comma delimiter and seperate categories into array
                                                
    $category = convert_category($category[0]);     
    $desc = clean($result[5]);     //clean() sanitizes data for query
    $instructions = clean($result['instructions']); 
    $keywords = clean($result[6]);                              
        $gamename = clean($gamename);
    $gamefile = clean($gamefile);
    $gamethumb = clean($gamethumb);
    $height = $result[4];
    $width = $result[3];
    
    $query = mysql_query("INSERT INTO `games` (`id`, `title`, `description`, `instructions`, `keywords`, `file`, `height`, `width`, `category`, `plays`, `code`, `type`, `thumbnail`, `ismochi`) VALUES (NULL, '$gamename', '$desc', '$instructions', '$keywords', '$gamefile', '$height', '$width', '$category', 0, '', 'SWF', '$gamethumb', 1)");
    if (!$query) { 
        echo 'Error updating Games database';
        return false;
    }
    $query = mysql_query("UPDATE mochigames SET isinstalled = 1 WHERE id = '{$result[0]}'");
    if (!query) {
        echo 'Error updating mochigame database';
        return false;
    }
    return true;                                                     
}