Javascript group by array content

Question

I have some problems figuring out how to group to certain variables in javascript.

Here is the deal.

I have one array containing categories in my case right now categories A-Z but it could be anything (Animals - dogs - cats - etc).

In another array I have a result from an xml file with different content (title, content and category). In my case the category containing letters from A-Z corresponding to the category in my other array.

So what I want to do is first of all output one div for each category from the category array. When that is done I want to add inside each div the matching category items form my other array.

This is an example

First output from my category array:

<div id="A"></div>
<div id="B"></div>
<div id="C"></div>
<div id="D"></div>

Second I want to add inside those divs the array objects that has a matching category inside them A, B, C etc.

<div id="A">
<div id="contentFromMyOtherArray"> this object comes from my other array and had the content category A </div>
<div id="contentFromMyOtherArray"> this object also comes from my other array and had the content category A still inside the A div </div>
</div>
<div id="B">
<div id="contentFromMyOtherArray"> this object comes from the array and had the content category B </div>
</div>

And so on...

Is this even possible?

EDIT: My First array only holds A, B, C, D, E etc so when iterating thru it array[i] i will get A B C D etc

My second array holds title category etc so if i want to have only the category i could iterate thru it like this arrMarkers[i].category. That would output ex. A A A B B E E F F F etc based on what categories the content of each array holds

you say groupBy the first thing came to mind is linq to js may be it ca help linqjs.codeplex.com — Rafay
– Rafay, Commented Sep 27, 2011 at 10:05

GregL · Accepted Answer · 2011-09-27 10:27:39Z

3

Assuming you have your arrays defined something like this:

var categories = ['A', 'B', 'C', 'D'];
var other = [];
other['A'] = ['item 1', 'item 2', 'item 3'];
other['B'] = ['item 4', 'item 5'];
other['C'] = ['item 6'];

Then try the following jQuery code to create the divs:

$(document).ready(function() {    
    $.each(categories, function(index, category) {
        var categoryId = category.replace(/ /gi, '_');
        var newCategory = $('<div />').attr('id', categoryId);
        // you can set any other properties on this new div here using .attr()
        $.each(other[category], function(index, item) {
            var itemId = category + '_' + item.replace(/ /gi, '_');
            var newInnerDiv = $('<div />').attr('id', itemId);
            // set any other properties like text content, etc here
            newInnerDiv.appendTo(newCategory);
        });
        newCategory.appendTo('body');
    });
});

You can see a working example here: http://jsfiddle.net/greglockwood/8F8hv/

Let me know if you have any problems.

answered Sep 27, 2011 at 10:27

GregL

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2 Comments

Tobias Over a year ago

Thanks for the answer GregL. This could also work really good. My problem is the "other" array is added dynamic. In this case I would need a way to group my array based on the category. Any clues?

Tobias Over a year ago

Its working now! Had to figure out a way to ad the content to the array. Thanks a lot for your time! :)

James Jithin · Accepted Answer · 2011-09-27 12:25:35Z

0

If the array from the xml can be set to a two dimensional one, things can go fine. Please look at his example:

html:

<div id="containerDiv">
    <div id="A"></div>
    <div id="B"></div>
    <div id="C"></div>
</div>

javascript/jQuery

var resultArray = [
    ["A", "Title1", "this object comes from my other array and had the content category A"],
    ["B", "Title2", "this object comes from my other array and had the content category B"],
    ["C", "Title3", "this object comes from my other array and had the content category C"],
    ["D", "Title4", "this object comes from my other array and had the content category D"],
    ["A", "Title5", "this object comes from my other array and had the content category A"],
    ["A", "Title6", "this object comes from my other array and had the content category A"],
    ["C", "Title7", "this object comes from my other array and had the content category C"],
    ["D", "Title8", "this object comes from my other array and had the content category D"],
    ["C", "Title9", "this object comes from my other array and had the content category C"],
    ["D", "Title10", "this object comes from my other array and had the content category D"],
    ["A", "Title11", "this object comes from my other array and had the content category A"],
    ["D", "Title12", "this object comes from my other array and had the content category D"],
    ["C", "Title13", "this object comes from my other array and had the content category C"],
    ["B", "Title14", "this object comes from my other array and had the content category B"]
];

$(document).ready(
    function() {
        var holderMap = new Array();
        $("div#containerDiv").children("div").each(
            function() {
                holderMap[$(this).attr("id")]=$(this);
            }
        );
        var elem = null;
        var value = null;
        $(resultArray).each(function() {
            elem = holderMap[$(this)[0]];
            value = $(this)[2];
            if(elem) {
                $(elem).html($(elem).html() + '<div id="contentFromMyOtherArray">' + value + '</div>');
            }
        });
    }
);

This code goes dynamic so that if a non categorized item is encountered, it skips automatically.

answered Sep 27, 2011 at 12:25

James Jithin

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2 Comments

Tobias Over a year ago

Thanks a lot! This looks promising. However the holderMap is undefined if I take a look at it like this holderMap[$(this)[0]]. What could that be?

James Jithin Over a year ago

See the scope of the variable you are accessing. In the above example, holderMap is defined as new Array() and the access to the variable happens inside the function. If you want to access the holderMap in a different scope or function, you may declare it global. i.e. above $(document).read();

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