一尘不染

PHP-使用Ajax刷新While循环数据

php

使用PHP ,我想做一个while循环,该循环读取一个大文件并在请求时发送当前行号。 使用Ajax ,我想获取当前行数并将其打印到页面上。
使用html按钮 ,我希望能够单击并激活或终止仅运行一次并调用 ajax方法 的javascript线程。

我给了它一个镜头,但是由于某种原因,除非我注释掉该echo str_repeat(' ',1024*64);函数,否则什么都不会打印,当注释掉它时,它将显示整个循环结果:

已处理1行,已处理2行,已处理3行,已处理4行,已处理5行,已处理6行,已处理7行8已处理行。已处理9行。已处理10行。

在一行中而不是在单独的行中显示它们,例如:

1 row(s) processed.
2 row(s) processed.
3 row(s) processed.
4 row(s) processed.
5 row(s) processed.
6 row(s) processed.
7 row(s) processed.
8 row(s) processed.
9 row(s) processed.
10 row(s) processed.

另外,我不确定如何终止JavaScript线程。因此共有2个问题:

 1. It's returning the entire While loop object at once instead of each time it loops.
 2. I'm not sure how to terminate the JQuery thread.

有任何想法吗?下面是到目前为止的代码。

msgserv.php

<?php

//Initiate Line Count
$lineCount = 0;

// Set current filename
$file = "test.txt";

// Open the file for reading
$handle = fopen($file, "r");

//Change Execution Time to 8 Hours
ini_set('max_execution_time', 28800);

// Loop through the file until you reach the last line
while (!feof($handle)) {

    // Read a line
    $line = fgets($handle);

    // Increment the counter
    $lineCount++;

    // Javascript for updating the progress bar and information
    echo $lineCount . " row(s) processed.";

    // This is for the buffer achieve the minimum size in order to flush data
    //echo str_repeat(' ',1024*64);

    // Send output to browser immediately
    flush();

    // Sleep one second so we can see the delay
    //usleep(100);
}

// Release the file for access
fclose($handle);

?>

asd.html

<html>
    <head>
        <script src="http://code.jquery.com/jquery-latest.min.js" type="text/javascript" charset="utf-8"></script>

        <style type="text/css" media="screen">
            .msg{ background:#aaa;padding:.2em; border-bottom:1px #000 solid}
            .new{ background-color:#3B9957;}
            .error{ background-color:#992E36;}
        </style>

    </head>
    <body>

    <center>
        <fieldset>
            <legend>Count lines in a file</legend>
            <input type="button" value="Start Counting" id="startCounting" />
            <input type="button" value="Stop Counting!" onclick="clearInterval(not-Sure-How-To-Reference-Jquery-Thread);" />
        </fieldset>
    </center>

    <div id="messages">
        <div class="msg old"></div>
    </div>

    <script type="text/javascript" charset="utf-8">
        function addmsg(type, msg){
            /* Simple helper to add a div.
        type is the name of a CSS class (old/new/error).
        msg is the contents of the div */
            $("#messages").append(
            "<div class='msg "+ type +"'>"+ msg +"</div>"
        );
        }

        function waitForMsg(){
            /* This requests the url "msgsrv.php"
        When it complete (or errors)*/
            $.ajax({
                type: "GET",
                url: "msgsrv.php",
                async: true, /* If set to non-async, browser shows page as "Loading.."*/
                cache: false,
                timeout:2880000, /* Timeout in ms set to 8 hours */

                success: function(data){ /* called when request to barge.php completes */
                    addmsg("new", data); /* Add response to a .msg div (with the "new" class)*/
                    setTimeout(
                    'waitForMsg()', /* Request next message */
                    1000 /* ..after 1 seconds */
                );
                },
                error: function(XMLHttpRequest, textStatus, errorThrown){
                    addmsg("error", textStatus + " (" + errorThrown + ")");
                    setTimeout(
                    'waitForMsg()', /* Try again after.. */
                    "15000"); /* milliseconds (15seconds) */
                },
            });
        };

        $('#startCounting').click(function() {
            waitForMsg();
        });
    </script>

</body>
</html>

test.txt

1
2
3
4
5
6
7
8
9
10

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2020-05-29

共1个答案

一尘不染

使用:

应该在一个php线程中完成所有您需要的工作

编辑

看一下nickb的答案,如果您正在寻找一种简单地执行此操作的方法,它将遵循以下算法:

  1. javascript process.php通过ajax 打开(它将完成所有工作并打印状态报告),您必须查看jQuery ajax是否支持连续加载
  2. 如果用户决定停止刷新,则您将按提供的链接中所示终止加载

process.php

ignore_user_abort(); // Script will finish in background
while(...){
  echo "Page: $i\n";
  ob_flush();
}

EDIT 2 要求的示例 (不同而难看,但简单)test_process.php

// This script will write numbers from 1 to 100 into file (whatever happens)
// And sends continuously info to user
$fp = fopen( '/tmp/output.txt', 'w') or die('Failed to open');
set_time_limit( 120);
ignore_user_abort(true);

for( $i = 0; $i < 100; $i++){
    echo "<script type=\"text/javascript\">parent.document.getElementById( 'foo').innerHTML += 'Line $i<br />';</script>";
    echo str_repeat( ' ', 2048);
    flush();
    ob_flush();
    sleep(1);
    fwrite( $fp, "$i\n");
}

fclose( $fp);

和主要的HTML页面:

<iframe id="loadarea"></iframe><br />
<script>
function helper() {
    document.getElementById('loadarea').src = 'test_process.php';
}
function kill() {
    document.getElementById('loadarea').src = '';
}
</script>

<input type="button" onclick="helper()" value="Start">
<input type="button" onclick="kill()" value="Stop">
<div id="foo"></div>

在按如下开始线后:

Line 1
Line 2

出现在div中#foo。当我点击时Stop,它们停止出现,但脚本在后台结束,并将所有100个数字写入文件中。

如果Start再次点击,脚本将从乞讨(重写文件)开始执行,并行请求也会执行。

有关http流的更多信息,请参见此链接

2020-05-29