CODEWITHSUNDEEP
javascriptjquery
Kleber Mota
Kleber Mota

Reputation: 9093

Verifiy if element exists before add to html page

In my current spring project, I have some <select> fields where the options inside are added through this jquery code:

function load_options(target, lista) {
    $.ajax({
        type: 'GET',
        url: lista
    }).done(function(data){
        var json = jQuery.parseJSON( data );
        $.each(json.item, function(index, item) {
            var option = $('<option class="form-control" value="'+item.id+'">'+item.nome+'</option>');
            if(<<condition>>)
                target.append(option);
        });
    });
}

I am looking for a <<condition>> where I can verifiy if the option stored in the variable exists before add it to select.

Anyone know how check this?

Upvotes: 1

Views: 53

Answers (2)

user2391174
user2391174

Reputation: 138

The jQuery constructor (that's where you pass in your selector) returns an array, so, if an element exists the length property of that array is 1 (or more). You could write you condition based on that.

Upvotes: 1

Rick Hitchcock
Rick Hitchcock

Reputation: 35680

I would do it this way, but I'd be interested in other solutions:

...
var json = jQuery.parseJSON( data );
var opt = [];
...
if(!opt[item.nome])
  target.append(option);

opt[item.nome]= true;
...

Upvotes: 1

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