get the next element with a specific class after a

问题:

I have a HTML markup like this:

<p>
  <label>Arrive</label>
  <input id="from-date1" class="from-date calender" type="text" />
</p>

<p>
  <label>Depart</label>
  <input id="to-date1" class="to-date calender" type="text" />
</p>

<p>
  <label>Arrive</label>
  <input id="from-date2" class="from-date calender" type="text" />
</p>

<p>
  <label>Depart</label>
  <input id="to-date2" class="to-date calender" type="text" />
</p>

I want to get the next element after from dates to get the corresponding to date. (Layout is a little more complex but from date has from-date class and to date has to-date class).

This is I am trying to do, I want to take a from date element and find the next element in the dom with to-date class. I tried this:

$('#from-date1').next('.to-date')

but it is giving me empty jQuery element. I think this is because next gives the next sibling matching the selector. How can I get the corresponding to-date?

回答1:

Couldn't find a direct way of doing this, so wrote a little recursive algorithm for this.

Demo: http://jsfiddle.net/sHGDP/

nextInDOM() function takes 2 arguments namely the element to start looking from and the selector to match.

instead of

$('#from-date1').next('.to-date')

you can use:

nextInDOM('.to-date', $('#from-date1'))

Code

function nextInDOM(_selector, _subject) {
    var next = getNext(_subject);
    while(next.length != 0) {
        var found = searchFor(_selector, next);
        if(found != null) return found;
        next = getNext(next);
    }
    return null;
}
function getNext(_subject) {
    if(_subject.next().length > 0) return _subject.next();
    return getNext(_subject.parent());
}
function searchFor(_selector, _subject) {
    if(_subject.is(_selector)) return _subject;
    else {
        var found = null;
        _subject.children().each(function() {
            found = searchFor(_selector, $(this));
            if(found != null) return false;
        });
        return found;
    }
    return null; // will/should never get here
}

回答2:

.next('.to-date') does not return anything, because you have an additional p in between

You need .parent().next().find('.to-date').

You might have to adjust this if your dom is more complicated than your example. But essentially it boils down to something like this:

$(".from-date").each(function(){
    // for each "from-date" input
    console.log($(this));
    // find the according "to-date" input
    console.log($(this).parent().next().find(".to-date"));
});

edit: It's much better and faster to just look for the ID. The following code searches all from-dates and gets the according to-dates:

function getDeparture(el){
    var toId = "#to-date"+el.attr("id").replace("from-date","");
    //do something with the value here
    console.log($(toId).val());
}

var id = "#from-date",
    i = 0;

while($(id+(++i)).length){
    getDeparture($(id+i));
}

Take a look at the example.

回答3:

try

var flag = false;
var requiredElement = null;
$.each($("*"),function(i,obj){
    if(!flag){
        if($(obj).attr("id")=="from-date1"){
            flag = true;
        }
    }
    else{
        if($(obj).hasClass("to-date")){
            requiredElement = obj;
            return false;
        }
    }
});

回答4:

    var item_html = document.getElementById('from-date1');
    var str_number = item_html.attributes.getNamedItem("id").value;
    // Get id's value.
    var data_number = showIntFromString(str_number);


    // Get to-date this class
    // Select by JQ. $('.to-date'+data_number)
    console.log('to-date'+data_number);

    function showIntFromString(text){
       var num_g = text.match(/\d+/);
       if(num_g != null){
          console.log("Your number:"+num_g[0]);
          var num = num_g[0];
          return num;
       }else{
          return;
       }
    }

Use JS. to get the key number from your id. Analysis it than output the number. Use JQ. selecter combine string with you want than + this number. Hope this can help you too.