Extend a JavaScript object

Question

I'm looping inputs in a table, that don't have any form tag. I get the values correctly. I want to build with their values an object that contains multiple objects.

What i'm expecting?

alarms = { alarm: { status_id: '1', alarm_name: 'Critic', user_id_created: '30021061' }, alarm: { status_id: '1', alarm_name: 'Middle', user_id_created: '30021061' }, alarm: { status_id: '1', alarm_name: 'Bottom', user_id_created: '30021061' }, ... };

What i'm getting? The last object in the loop.

alarms = { alarm: { status_id: '1', alarm_name: 'Bottom', user_id_created: '30021061' } };

Here is the code:

var alarms = {}
$('.new_alarm').each(function() {
    var status_id = $(this).children('.status').children().val(),
        alarm_name = $(this).children('.data').children('input[name="alarm_name"]').val(),
        user_id = $('#user_id').text();
        objAux = {};

    if(alarm_name) {            
        objAux = {
            alarm: {
                'status_id': status_id,
                'alarm_name': alarm_name,
                'user_id_created': user_id
            }
        };
    }

    alarms = $.extend(true, alarms, objAux);          
});

What's wrong with the jQuery extend method? Why is not merging the objects?

Did you really have to post that JSON all on one line?

Lightness Races in Orbit
– Lightness Races in Orbit

2011-06-23 20:24:15 +00:00
Commented Jun 23, 2011 at 20:24 — Lightness Races in Orbit
– Lightness Races in Orbit, Commented Jun 23, 2011 at 20:24

aepheus · Accepted Answer · 2011-06-23 19:55:35Z

4

If I'm not mistaken, what you want is actually impossible. It's akin to saying you want an array to have 5 values for the a[1].

You could implement this using an array instead of an object:

alarms = [{...},{...},{...}];

What you're writing is actually this:

alarms['alarm'] = {...};
alarms['alarm'] = {...};
alarms['alarm'] = {...};
alarms['alarm'] = {...};

answered Jun 23, 2011 at 19:55

aepheus

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3 Comments

betacar Over a year ago

I need it that way to send it over AJAX to a Rails server. Rails only process, if I'm not mistaken, only hashes (aka JSON objects).

Sophie Alpert Over a year ago

JSON objects can definitely contain arrays and Rails should have no problem with that.

Lightness Races in Orbit Over a year ago

Ruby does not mind JSON arrays. Not sure where you got that from, betacar.

peterp · Accepted Answer · 2011-06-23 19:59:09Z

1

You're overriding the same property "alarm" on every iteration.

You should be creating an Array and then push() the values on the end of an Array.

var alarms = [
      {name: 'alarm1'}
    , {name: 'alarm2'}
    , {name: 'alarm3'}
];


var new_alarms = [];


$(alarms).each(function() {
    console.log(this);
    new_alarms.push(this);
});


console.log(alarms, new_alarms);

See: http://jsfiddle.net/y22Hk/

answered Jun 23, 2011 at 19:59

peterp

3,1651 gold badge22 silver badges24 bronze badges

3 Comments

betacar Over a year ago

I need it that way to send it over AJAX to a Rails server. Rails only process, if I'm not mistaken, only hashes (aka JSON objects).

Lightness Races in Orbit Over a year ago

Ruby does not mind JSON arrays. Not sure where you got that from, betacar. Also, "I need it that way" is an odd thing to say about something that is physically and mathematically impossible...

betacar Over a year ago

A read it while ago (don't remember where). Thank's for the article. :)

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