Check if key/value pair within an array exists using Underscore JS _contains method

Question

If I have the following object:

var record = {
    title: "Hello",
    children: [
        {
            title: "hello",
            active: true
        },
        {
            title: "bye",
            active: false
        }
};

I want to use underscore to determine if one of the children within the record has or does not have a title equal to a variable that will come from a form post, but also needs to be case insensitive... So for example:

var child = { title: "heLLo", active: true }

And underscore ( and this is wrong, and what I need help with ):

if ( _.contains(record.children, child.title) ) {
    // it already exists...
} else {
    // ok we can add this to the object
}

So basically I don't understand how to do this with underscore when dealing with array objects that have multiple key/value pairs. Also what is the best method for ignoring case? Should this be done in the underscore _.contains function? Regex? Use toLowerCase() beforehand to create the variables? If someone types in any variation of "Hello", "HELLO", "heLLO", etc. I don't want the insert to take place.

Thank you!

Jevgeni · Accepted Answer · 2014-10-01 17:08:20Z

2

Use _.find and RegExp with "i" case-ignore flag

var valueFromPost = "bye";
var someOfChildrenHasValueFromPost = _.find(record.children,function(child){
    return child.title.match(new RegExp(valueFromPost,"i"));
});

Update

Here is an example @JSFiddle

JS code:

record = {
    children:[
        {title:'bye'},
        {title:'Bye'},
        {title:'Hello'}
        ]
}
var testValue = function(value) {
    return  _.find(record.children,function(child){
        return child.title.match(new RegExp(value,"i"));
    });
}
console.debug(testValue('Bye')); //returns object with "Bye" title
console.debug(testValue('What'));//returns undefined
console.debug(testValue('bye')); //returns object with "bye" title

edited Oct 1, 2014 at 17:08

answered Oct 1, 2014 at 16:28

Jevgeni

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1 Comment

user1447679 Over a year ago

Thank you. I'm having a problem though. This is returning a value each time no matter what I use as the form post. For example if I console.log(someOf....) I get Object {title: "test", sort: "", active: false} each time, so I'm unable to create an "undefined" scenario. What could I be doing wrong?

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