如何根据json应显示的日期和时间显示json收到的字符串元素？

Question

我有一个数据库,我在那里存储一个文本,它的持续时间和它应该出现在网页上的时间.

php的结果如下:

{"text_content":"dgsgdsgds","text_duration":"15","start_time":"2015-09-28 23:11:15"},{"text_content":"dgsgdsgds","text_duration":"15","start_time":"2015-09-28 23:11:30"},{"text_content":"gdsgdsgds","text_duration":"15","start_time":"2015-10-01 14:00:00"}

我有一个jquery脚本从数据库中提取数据并将其打印在屏幕上:

var results =[];
var cursor = 0;

function myFunction () {
    $.getJSON('list2.php', function(json) {
        results = json;
        cursor = 0;

        // Now start printing
        printNext();
    });
}

function printNext(){
    if(cursor == results.length){
        // Reset the cursor back to the beginning.
        cursor = 0;
    }

    // Print the key1 in the div.
    //$('#mydiv').html(results[cursor].key1);
    $('#mydiv').hide('fast', function(){ $('#mydiv').html(results[cursor].text_content); $('#mydiv').show('fast'); });

    // Set a delay for the current item to stay
    // Delay is key2 * 1000 seconds
    setTimeout(function(){
        printNext();
    }, results[cursor].text_duration * 1000);

    // Advance the cursor.
    cursor++;
}

现在我想添加一个功能,只有在从数据库中提取的日期才能在屏幕上显示文本start_time,但是我不确定是否可以仅在jquery上执行,而无需进一步访问服务器代码.我尝试添加一些if语句,如:

if(results[cursor].start_time == new Date()){

就在将它打印在屏幕上之前,但它没有做到这一点.你能帮帮我吗？谢谢!

Answer 1

解析你的json字符串JSON.parse:

var myObj = JSON.parse(results[0]);

并比较你的start_time:

if (new Date(myObj.start_time) == new Date())

如果你想在特定的时间运行你的函数使用setTimeout:

var diff = new Date(myObj.start_time).getTime() - new Date().getTime();
setTimeout(function() {
    $('#mydiv').hide('fast', function() {
        $('#mydiv').html(results[cursor].text_content);
        $('#mydiv').show('fast');
    });
}, diff)

或者你可以通过使用setInterval并每隔1000毫秒执行一次你的功能clearInterval:

function check() {
    if (new Date(myObj.start_time) == new Date()) {
        $('#mydiv').hide('fast', function() {
            $('#mydiv').html(results[cursor].text_content);
            $('#mydiv').show('fast');
        });
        clearInterval(myInterval);
    }
}

var myInterval = setInterval(check, 1000)