Remove specific element from array in Knockout.JS

Question

I am creating a multiplayer game over network so I have to react on network events.

I have this simple code, but the removePlayer method doesnt work. The addPlayer() works fine.

<table id="userlist2" class="tablesorter" cellspacing="0">
    <thead>
        <tr>
            <th>Name</th>
            <th>Queue</th>
            <th>Points</th>
        </tr>
    </thead>
    <tbody data-bind="foreach: players">
        <tr>
            <td data-bind="text: name"></td>
            <td data-bind="text: queue"></td>
            <td data-bind="text: score"></td>
        </tr>
    </tbody>
</table>


function PlayerViewModel() {
    var self = this;
    self.players = ko.observableArray();

    self.addPlayer = function (Name, QueuePos, Score) {
        self.players.push({
            name: Name,
            queue: QueuePos,
            score: Score
        });
    }


    self.removePlayer = function (Name) {
        for (var i = 0; i < self.players().length; i++) {

            if (self.players()[i].name == Name) console.log(i);
            self.players().splice(i, 1);
        }
    }
}


players = new PlayerViewModel();
ko.applyBindings(players);

players.addPlayer('Player1', '0', '0');
players.addPlayer('Player2', '0', '0');
players.removePlayer('Player2');

Heres the http://jsfiddle.net/xseTc/

Solution 1

You have to use the remove function :

self.removePlayer = function (Name) {
    self.players.remove(function(player) {
        return player.name == Name;
    });
    
}

See fiddle

html

<table id="userlist2" class="tablesorter" cellspacing="0">
    <thead>
        <tr>
            <th>Name</th>
            <th>Queue</th>
            <th>Points</th>
        </tr>
    </thead>
    <tbody data-bind="foreach: players">
        <tr>
            <td data-bind="text: name"></td>
            <td data-bind="text: queue"></td>
            <td data-bind="text: score"></td>
        </tr>
    </tbody>
</table>

javascript

function PlayerViewModel() {
    var self = this;
    
    self.players = ko.observableArray();  

    self.addPlayer = function (Name, QueuePos, Score) {
        self.players.push({
            name: Name,
            queue: QueuePos,
            score: Score
        });
    }

    self.removePlayer = function (Name) {
        self.players.remove(function(player) {
            return player.name == Name;
        });
    }
}

players = new PlayerViewModel();
ko.applyBindings(players);

players.addPlayer('Player1', '0', '0');
players.addPlayer('Player2', '0', '0');
players.removePlayer('Player2');

Solution 2

Working remove function:

self.removePlayer = function (name) {
    self.players.remove(function(player) { 
        return player.name == name
    });
}

Solution 3

your code is fine except 2 error you have:

if (self.players()[i].name == Name) console.log(i);
    self.players().splice(i, 1);

first here you are executing 2 lines so to execute them both you need to use {} so replace it with:

if (self.players()[i].name == Name) {
    console.log(i);
    self.players.splice(i, 1);
}

second to use splice you done need to call your observable array with () so you to use it as following :

self.players.splice(i, 1);

Working Demo

Comments

[ebram khalil]

i updated 2 lines of your code check my answer

[Karussell]

isn't it player.name() == Name ?

[deblocker]

@karussel: ...just because not even one answered to this comment: it's a "streamlined" structure, single Player properties aren't observable.