Skip to main content

Gathering segmented data via jQuery with FOR loops

Image
By User



Here's my code (what I'm stuck on is after the jump)







<script language="JavaScript" type="text/javascript" src="http://code.jquery.com/jquery-1.7.1.min.js"></script>

<script type="text/javascript">

var countThisMany = 4; //how many data-id's I want to count per "section" of images

var finalString = "";  //blank var to be used later, must be defined here.

</script>



<img src="foo.jpg" data-id="id1" data-item="1" />    // just a bunch

<img src="foo.jpg" data-id="id2" data-item="2" />    // of images with

<img src="foo.jpg" data-id="id3" data-item="3" />    // data-* usage to

<img src="foo.jpg" data-id="id4" data-item="4" />    // store two bits

<img src="foo.jpg" data-id="id5" data-item="5" />    // of information

<img src="foo.jpg" data-id="id6" data-item="6" />    // that I'll need

<img src="foo.jpg" data-id="id7" data-item="7" />    // to extract

<img src="foo.jpg" data-id="id8" data-item="8" />    // later on below.



<img src="bar.jpg" data-id="id9" data-item="1" />    // another set of images

<img src="bar.jpg" data-id="id10" data-item="2" />

<img src="bar.jpg" data-id="id11" data-item="3" />

<img src="bar.jpg" data-id="id12" data-item="4" />

<img src="bar.jpg" data-id="id13" data-item="5" />

<img src="bar.jpg" data-id="id14" data-item="6" />

<img src="bar.jpg" data-id="id15" data-item="7" />

<img src="bar.jpg" data-id="id16" data-item="8" />



<script type="text/javascript">

var item_array = $("img").map(function() {

    return $(this).attr("data-item");

}).get();



//alert(item_array);

//returns "1,2,3,4,5,6,7,8,1,2,3,4,5,6,7,8"





var id_array = $("img").map(function() {

    return $(this).attr("data-id");

}).get();

//alert(id_array);

//returns "id1,id2,id3,id4,id5,id6,id7,id8,id9,id10,id11,id12,id13,id14,id15,id16"





for (i=0;i<countThisMany;i++){

finalString=finalString+id_array[i]+';';

}



//alert(finalString);

//returns "id1;id2;id3;id4" -- could be more or less if "countThisMany" is changed to something other than 4 



</script>







This entire code is self-contained so feel free to save it as an HTML and uncomment the alerts to see the results.





What I need, however, is a step further. I would like to only collect the data-id of the img tags whose data-item are less than or equal to the variable countThisMany





So the end result of finalString would be "id1;id2;id3;id4;id9;id10;id11;id12". And if countThisMany was changed to 2, for instance, it would be "id1;id2;id9;id10"





I feel as though I am so close but I can't figure out how to only gather the first 4 of the first set of 8 images, and the first 4 of the second set of 8 images. Again, the total amount of images and how many I would need to capture vary, hence the "countThisMany' var.





This is my first post to the amazing stackoverflow community, so I'm excited! Thanks to all contributors ahead of time!


Labels:

Comments

  1. Tips For AllJanuary 30, 2012 at 2:13 AM

    Use filter method

    var item_array = $("img").filter(function() {
    return parseInt($(this).data("item")) <= countThisMany;
    }).map(function() {
    return $(this).data('id');
    }).get();

    ReplyDelete
  2. Tips For AllJanuary 30, 2012 at 2:13 AM

    var countThisMany = 4;
    var item_array = $("img")
    .filter(function() {
    return parseFloat( $(this).attr("data-item") ) <= countThisMany;
    })
    .map(function() {
    return $(this).attr("data-id");
    })
    .toArray(); /* instead of get() */


    Note that this will return an array. You seem to want a string, so you might want to call .join(',') on the result.

    ReplyDelete
  3. Tips For AllJanuary 30, 2012 at 2:13 AM

    Use $.grep in combination with $.map. I also added a join to array rather than the loop. fiddle: http://jsfiddle.net/brentmn/5yNbE/5/

    var countThisMany = 2;
    var finalString = "";

    var id_array = $.grep($('img'), function(item) {
    return ($(item).data('item') <= countThisMany);
    }).map(function(item) {
    return $(item).data('id')
    });

    finalString = id_array.join(';');

    ReplyDelete

Post a Comment

Popular posts from this blog

[韓日関係] 首相含む大幅な内閣改造の可能性…早ければ来月１０日ごろ＝韓国

By Unknown
Post a Comment
Read more

div not scrolling properly with slimScroll plugin

By User
I am using the slimScroll plugin for jQuery by Piotr Rochala Which is a great plugin for nice scrollbars on most browsers but I am stuck because I am using it for a chat box and whenever the user appends new text to the boxit does scroll using the .scrollTop() method however the plugin's scrollbar doesnt scroll with it and when the user wants to look though the chat history it will start scrolling from near the top. I have made a quick demo of my situation http://jsfiddle.net/DY9CT/2/ Does anyone know how to solve this problem?
1 comment
Read more

Why does this javascript based printing cause Safari to refresh the page?

By User
The page I am working on has a javascript function executed to print parts of the page. For some reason, printing in Safari, causes the window to somehow update. I say somehow, because it does not really refresh as in reload the page, but rather it starts the "rendering" of the page from start, i.e. scroll to top, flash animations start from 0, and so forth. The effect is reproduced by this fiddle: http://jsfiddle.net/fYmnB/ Clicking the print button and finishing or cancelling a print in Safari causes the screen to "go white" for a sec, which in my real website manifests itself as something "like" a reload. While running print button with, let's say, Firefox, just opens and closes the print dialogue without affecting the fiddle page in any way. Is there something with my way of calling the browsers print method that causes this, or how can it be explained - and preferably, avoided? P.S.: On my real site the same occurs with Chrome. In the ex
5 comments
Read more