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Creating an element and insertBefore is not working

开发者 https://www.devze.com 2022-12-28 05:38 出处:网络
Ok, I\'ve been banging my head up against the wall on this and I have no clue why it isn\'t creating the element.Maybe something very small that I overlooked here.Basically, there is this Javascript c

Ok, I've been banging my head up against the wall on this and I have no clue why it isn't creating the element. Maybe something very small that I overlooked here. Basically, there is this Javascript code that is in a PHP document being outputted, like somewhere in the middle of when the page gets loaded, NOW, unfortunately it can't go into the header. Though I'm not sure that that is the problem anyways, but perhaps it is... hmmmmm.

// Setting the variables needed to be set.
    echo '
        <script type="text/javascript" src="' . $settings['default_theme_url'] . '/scripts/shoutbox.js"></script>';
    echo '
        <script type="text/javascript">
            var refreshRate = ', $params['refresh_rate'], ';
            createEventListener(window);
            window.addEventListener("load", loadShouts, false);

            function loadShouts()
            {
                var alldivs = document.getElementsByTagName(\'div\');
                var shoutCount = 0;
                var divName = "undefined";

                for (var i = 0; i<alldivs.length; i++)
                {
                    var is_counted = 0;
                    divName = alldivs[i].getAttribute(\'name\');

                    if (divName.indexOf(\'dp_Reserved_Shoutbox\') < 0 && divName.indexOf(\'dp_Reserved_Counted\') < 0)
                        continue;
                    else if(divName == "undefined") 
                        continue;
                    else
                    {
                        if (divName.indexOf(\'dp_Reserved_Counted\') == 0)
                        {
                            is_counted = 0;
                            shoutCount++;
                            continue;
                        }
                        else
                        {
                            shoutCount++;
                            is_counted = 1;
                        }
                    }

                    // Empty out the name attr.
                    alldivs[i].name = \'dp_Reserved_Counted\';

                    var shoutId = \'shoutbox_area\' + shoutCount;

                    // Build the div to be inserted.
                    var shoutHolder = document.createElement(\'div\');
                    shoutHolder.setAttribute(\'id\', [shoutId]);
                    shoutHolder.setAttribute(\'class\', \'dp_control_flow\');
                    shoutHolder.style.cssText = \'padding-right: 6px;\';
                    alldivs[i].parentNode.insertBefore(shoutHolder, alldivs[i]);

                    if (is_counted == 1)
                    {
                        startShouts(refreshRate, shoutId);
                        break;
                    }
                }
            }

        </script>';

Also, I'm sure the other functions that I'm linking to within these functions work just fine. The problem here is that within this function, the div never gets created at all and I can't understand why? Furthermore Firefox, FireBug is telling me that the variable divName is undefined, even though I have attempted to take care of this within the function, though not sure why.

Anyways, I need the created div element to be inserted just before the following HTML:

echo '
            <div name="dp_Reserved_Shoutbox" style="padding-bottom: 9px;"></div>';

I'm using name here instead of id because I don't want duplicate id values which is why I'm changing the name value and incrementing, since this function may be called more than 1 time. For example if there are 3 shoutboxes on the same page (Don't ask why...lol), I need to skip the other name开发者_StackOverflow中文版s that I already changed to "dp_Reserved_Counted", which I believe I am doing correctly. In any case, if I could I would place this into the header and have it called just once, but this isn't possible as these are loaded and no way of telling which one's they are, so it's directly hard-coded into the actual output on the page of where the shoutbox is within the HTML. Basically, not sure if that is the problem or not, but there must be some sort of work-around, unless the problem is within my code above... arrg

Please help me. Really what I need is a second set of eyes on this. Thanks :)


When you're testing divName, switch the order of your conditions from this

                divName = alldivs[i].getAttribute(\'name\');

                if (divName.indexOf(\'dp_Reserved_Shoutbox\') < 0 && divName.indexOf(\'dp_Reserved_Counted\') < 0)
                    continue;
                else if(divName == "undefined") 
                    continue;

to this:

                var divName = alldivs[i].getAttribute(\'name\');
                if (!divName) // this is sufficient, by the way
                    continue;
                else if (divName.indexOf(\'dp_Reserved_Shoutbox\') < 0 && divName.indexOf(\'dp_Reserved_Counted\') < 0)
                    continue;

The problem is that when the script finds a div without a name, it tries to call the indexOf property of a non-existent value and therefore throws an error.


There were a number of issues in the loadShouts method. First being the comparison of a string "undefined" instead of a straight boolean check, which will match. I also removed a bunch of un-needed logic. Beyond this, the id attribute being assigned to the new shoutHolder was being passed in as an array, instead of a direct property assignment.. See if the following works better.

function loadShouts()
{
  var alldivs = document.getElementsByTagName("div");
  var shoutCount = 0;
  var divName = "undefined";

  for (var i = 0; i<alldivs.length; i++)
  {
    divName = alldivs[i].getAttribute("name");

    if (!divName)
      continue;
    if (divName.indexOf("dp_Reserved_Shoutbox") < 0 && divName.indexOf("dp_Reserved_Counted") < 0)
      continue;

    shoutCount++;    
    if (divName.indexOf("dp_Reserved_Counted") == 0)
      continue;

    // Empty out the name attr.
    alldivs[i].setAttribute("name", "dp_Reserved_Counted");

    var shoutId = "shoutbox_area" + shoutCount;

    // Build the div to be inserted.
    var shoutHolder = document.createElement("div");
    shoutHolder.setAttribute("id", shoutId);
    shoutHolder.setAttribute("class", "dp_control_flow");
    shoutHolder.style.cssText = "padding-right: 6px;";
    alldivs[i].parentNode.insertBefore(shoutHolder, alldivs[i]);

    startShouts(refreshRate, shoutId);
    break;
  }
}


Ok, just wanted to let you know how it went. And I thank both you greatly Tracker1 and Casey Hope. Especially Tracker for the excellent rewrite of the function. You all ROCK. Here's the final function that I'm using bytheway, just a tiny bit of editing to Tracker1's Answer, which is why you got my vote hands down!

echo '
    <script type="text/javascript">
        var refreshRate = ' . $params['refresh_rate'] . ';
        createEventListener(window);
        window.addEventListener("load", loadShouts, false);

        function loadShouts()
        {
          var alldivs = document.getElementsByTagName("div");
          var shoutCount = 0;
          var divName = "undefined";

          for (var i = 0; i<alldivs.length; i++)
          {
            divName = alldivs[i].getAttribute("name");

            if (!divName)
              continue;
            if (divName.indexOf("dp_Reserved_Shoutbox") < 0 && divName.indexOf("dp_Reserved_Counted") < 0)
              continue;

            shoutCount++;    
            if (divName.indexOf("dp_Reserved_Counted") == 0)
              continue;

            // Empty out the name attr.
            alldivs[i].setAttribute("name", "dp_Reserved_Counted");

            var shoutId = "shoutbox_area" + shoutCount;

            // Build the div to be inserted.
            var shoutHolder = document.createElement("div");
            shoutHolder.setAttribute("id", shoutId);
            shoutHolder.setAttribute("class", "dp_control_flow");
            shoutHolder.style.cssText = "padding-right: 6px;";
            alldivs[i].parentNode.insertBefore(shoutHolder, alldivs[i]);

            startShouts(refreshRate, shoutId);
            break;
          }
        }

    </script>';

Thanks Again, you are the BEST!

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