如何从 jQuery ajax 成功函数返回一个数组并在循环中使用它？

Question

我想让每个帖子的时间实时更改。

这只是带有时间的字体，因为这是要在这里很重要。

<font class="timestamp" postdate="unixTimeStamp" postID="6">2 min ago</font>

<font class="timestamp" postdate="unixTimeStamp" postID="5">4 min ago</font>

<font class="timestamp" postdate="unixTimeStamp" postID="4">9 min ago</font>

这是javascript

setInterval(updateTimestamps,30000);

var realTime=<?php echo time();?>;

function updateTimestamps(){

  $(".timestamp").each(function(i){

     var timestamp=$(this).attr("postdate"),
     postID=$(this).attr("postID"),
     math=realTime-timestamp;

  if(math<3600){var dataString='postID='+postID+'&timestamp='+timestamp;

           $.ajax({
                     type:"POST",
                     url:"http://site.com/ajax/humanTime.php",
                     data:dataString,
                     cache:false,
                     success:function(html){
                                $("[postID='"+postID+"']").html(html);
                     }

            });

  }

});

}

在 humanTime.php 我计算时间：

$timestamp = $_POST['timestamp'];

$now=time(); $diff= $now - $timestamp;  and so on..

但问题是它建立了许多连接，因为每个帖子都会调用脚本。并认为也许我可以建立 1 个连接，将数据排序到一个数组中，然后更改时间。但我从未使用过 json，我确定我想要的是否真的可能

Answer 1

为什么要计算服务器端的人工时间？您也可以在客户端完美地进行这些计算。

setInterval(updateTimestamps,30000);

var currentTime=<?php echo time();?>;

function updateTimestamps(){

  $(".timestamp").each(function(i){
        var timestamp=$(this).attr("postdate");
        $(this).text(humanTime(currentTime, timestamp));
    });

}

function humanTime(currentTime, timestamp) 
{
    var diff = currentTime - timestamp,
    minute = 60,
    hour = minute * 60,
    day = hour * 24,
    week = day * 7;

    if (isNaN(diff) || diff < 0) {
        return ""; // return blank string if unknown
    }

    if (diff < second * 2) {
        // within 2 seconds
        return 'right now';
    }

    if (diff < minute) {
        return Math.floor(diff / second) + 'seconds ago';
    }

    if (diff < minute * 2) {
        return 'about one minute';
    }

    if (diff < hour) {
        return Math.floor(diff / minute) + 'minutes ago';
    }

    if (diff < hour * 2) {
        return 'about an hour ago';
    }

    if (diff < day) {
        return  Math.floor(diff / hour) + 'hours ago';
    }

    if (diff > day && diff < day * 2) {
        return 'yesterday';
    }

    if (diff < day * 365) {
        return Math.floor(diff / day) + 'days ago';
    }

    else {
        return 'more then a year ago';
    }
}

此函数借用自：http://www.queness.com/post/8567/create-a-dead-simple-twitter-feed-with-jquery

如前所述：使用<span> 标记或HTML5 标记<time>。

Answer 2

我会这样做：

setInterval(updateTimestamps,30000);
var ids = new Array();

function updateTimestamps(){
    $(".timestamp").each(function(i){
    var obj = new Object();
    obj.id = $(this).attr("postID");
    obj.timestamp = $(this).attr("postdate");
        ids.push(obj);
    }

    $.post("http://site.com/ajax/humanTime.php", {"time": ids}, function(data) {
        for (i = 0; i < data.length; i++) {
            $("#" + data[i].id).html(data[i].content);
        }
    }, "json");
}

编辑： 在humanTime.php中：

<?php 
    $ids = json_decode($_POST['time']);
    foreach($ids as $id) {
        // Calculate human time ...
    }
?>

然后返回如下内容：

[{id:1, content:1 minute ago}, {id:3, content: 5 hours ago}]

PS：这个解决方案是你要求的，但我认为 Bram 方法更好。

Answer 3

<!-- if you like something simple :) -->
<span class="timestamp" data-unix="<?php echo time();?>">posted now</span>
<script type="text/javascript">
setInterval(function() {
     $('span').each(function() {
        var d = new Date();
        // difference in minutes from now
        var diff = Math.round(d.getTime()/60000 - $(this).attr('data-unix')/60);
        $(this).html(diff + ' mins ago');
    });
}, 60000);
</script>

Answer 4

如何在您的时间间隔在客户端处理它：

示例标记可以是 div、span 等。

<div class="timestamp" postID="6"></div>
<div class="timestamp" postID="2"></div>
<div class="timestamp" postID="3"></div>

这支持现在和未来以及泛型。

var time_formats = [
    [60, 'just now', 1],
    [120, '1 minute ago', '1 minute from now'],
    [3600, 'minutes', 60],
    [7200, '1 hour ago', '1 hour from now'],
    [86400, 'hours', 3600],
    [172800, 'yesterday', 'tomorrow'],
    [604800, 'days', 86400],
    [1209600, 'last week', 'next week'],
    [2419200, 'weeks', 604800],
    [4838400, 'last month', 'next month'],
    [29030400, 'months', 2419200],
    [58060800, 'last year', 'next year'],
    [2903040000, 'years', 29030400],
    [5806080000, 'last century', 'next century'],
    [58060800000, 'centuries', 2903040000]
    ];

function prettydate(date_str) {
    var time = ('' + date_str).replace(/-/g, "/").replace(/[TZ]/g, " ");
    var seconds = (new Date() - new Date(time)) / 1000;
    var token = 'ago';
    var list_choice = 1;
    if (seconds < 0) {
        seconds = Math.abs(seconds);
        token = 'from now';
        list_choice = 2;
    }
    var i = 0,
        format;
    while (format = time_formats[i++]) if (seconds < format[0]) {
        if (typeof format[2] == 'string') return format[list_choice];
        else return Math.floor(seconds / format[2]) + ' ' + format[1] + ' ' + token;
    }
    return time;
}

// these would normally come from your ajax/creation of the element
$('.timestamp[postID=6]').data('postdate', '2012-03-20T09:24:17Z');
$('.timestamp[postID=2]').data('postdate', '2012-03-20T10:24:17Z');
$('.timestamp[postID=3]').data('postdate', '2012-03-20T08:24:17Z');

function formatTimes() {
    $('.timestamp').each(function() {
        $(this).text(prettydate($(this).data('postdate')));
    });
}
setTimeout(formatTimes, 30000);

工作示例：http://jsfiddle.net/MarkSchultheiss/6HKmS/