What is the best way to capture ng-keypress/ $event when the user clicks outside of a div?

Question

What is the best way to capture ng-keypress/ $event when the user clicks outside of a div?

I am currently working on developing a Sudoku game using AngularJS. My goal is to capture the ng-keypress event even when clicking outside of the div on the page. An example of this behavior can be seen at . If you select a cell and then click anywhere else on the page, you can still change the number in the selected cell by clicking on any number. How can I implement this functionality?

Here's an excerpt of the HTML code:

<table class="sudoku-board" ng-init="getSudoku()" id="sudoku"
                                   ng-class="{'paused': visible}">
                                <tbody>
                                    <tr class="sudoku-row" ng-repeat="sudoku in sudokuGrid track by $index"
                                        ng-init="row = $index">
                                        <td class="sudoku-col sudoku-cell" ng-repeat="number in sudoku track by $index"
                                            ng-init="col = $index" ng-class="{'highlight': colSelected === col || isHighlight(row, col) || rowSelected === row,
                                            'highlight-number':getValue === number.substring(0, 1), 'selected':isSelected === ((row*10) + col), 'paused': visible}"
                                            ng-click="selectedCell(row, col)"
                                            ng-keydown="insertNum($event, row, col);" tabindex="1">
                                            <span class="cell-value"
                                                  ng-class="{'empty': number === null || number.charAt(number.length-1) === '!', 'default': number !== null, 'paused': visible}"
                                                  ng-bind="number.substring(0, 1)"></span>
                                        </td>
                                    </tr>
                                </tbody>
                            </table>

The function triggered on ng-keydown is as follows:

// handle inserted value
$scope.insertNum = function (e, row, col, number) {
    console.log("Number: " + number);
    $scope.selectedCol = col; // get selected column
    $scope.selectedRow = row; // get selected row
    console.log(e);
    if (e !== undefined) {
        var keyCode = e.keyCode || e.charCode; // assign key & char code
        if ((keyCode < 49 || ((keyCode > 57 && keyCode < 97) || keyCode > 105)) && (keyCode !== 8 && keyCode !== 46))
            return false; // return false if clicked button/event is not a number or delete/backspace button

        if (e.currentTarget.children[0].classList[2] === 'empty') // check if clicked cell is empty
            if (keyCode === 8 || keyCode === 46) { // remove current value if delete/backspace is clicked
                e.currentTarget.children[0].innerHTML = null;
                $scope.sudokuGrid[row][col] = null;
                $(e.target).removeClass("incorrect");
                $(e.target).removeClass("correct");
                $scope.handleErrorClass();
                $scope.getValue = false;
            }
            else { // insert number in cell when number is clicked
                e.currentTarget.children[0].innerHTML = e.key;
                $scope.sudokuGrid[row][col] = e.key + "!";
                $scope.checkCurrentNumber(row, col);
                $scope.getCurrentNumber(row, col);

                // add correct class if inserted number is correct
                if (e.key === $scope.sudokuGridSolved[row][col]) {
                    console.log("Correct");
                    $(e.target).removeClass("incorrect");
                    $(e.target).addClass("correct");
                }
                // add incorrect class if inserted number is not correct
                else {
                    console.log("Incorrect");
                    $(e.target).removeClass("correct");
                    $(e.target).addClass("incorrect");
                }
            }
    }
    else {
        if (number !== null && $("tr:eq(" + $scope.selectedRow + ") td:eq(" + $scope.selectedCol + ") span").hasClass("empty")) {
            $("tr:eq(" + $scope.selectedRow + ") td:eq(" + $scope.selectedCol + ") span").html(number);
            $scope.sudokuGrid[row][col] = number + "!";
            $scope.checkCurrentNumber(row, col);
            $scope.getCurrentNumber(row, col);

            // add correct class if inserted number is correct
            if ($scope.getValue === $scope.sudokuGridSolved[row][col]) {
                console.log("Correct");
                $("tr:eq(" + $scope.selectedRow + ") td:eq(" + $scope.selectedCol + ")").removeClass("incorrect");
                $("tr:eq(" + $scope.selectedRow + ") td:eq(" + $scope.selectedCol + ")").addClass("correct");
            }
            // add incorrect class if inserted number is not correct
            else {
                console.log("Incorrect!");
                $("tr:eq(" + $scope.selectedRow + ") td:eq(" + $scope.selectedCol + ")").removeClass("correct");
                $("tr:eq(" + $scope.selectedRow + ") td:eq(" + $scope.selectedCol + ")").addClass("incorrect");
            }
        }
    }
    $scope.checkForIdenticalValues();
}

javascript angularjs events event-handling

Answer 1

Answer №1

It seems that the issue arises because the ng-keydown is placed on the <td> tag, which means the function will only trigger when that element is currently focused. If you want to respond to key down events from anywhere on the page, you can achieve this by attaching the ng-keydown to the body tag instead of the <td>. Then, have the function broadcast an event that can be picked up by the sudoku component to execute the insertNum logic.

<body ng-keydown="onMyKeydownEvent($event)">

Next, define the function on the $rootScope in the run() block to broadcast the event.

app.run(function($rootScope) {
  $rootScope.onMyKeydownEvent = function(e) {
    $rootScope.$broadcast("MyKeydownEvent", e);
  };
});

Add a listener for this event in your component.

$scope.$on("MyKeydownEvent", function(e) {
  // InsertNum logic implementation goes here.
});

Please note that adjustments need to be made to some parts of the logic, such as utilizing e.currentTarget and updating variables like $scope.selectedCol = col; and $scope.selectedRow = row;. Instead, consider using the

ng-click="selectedCell(row, col)"

directly on the <td> tag to manage setting the necessary cell data in the scope for event handling.

Answer 2

It seems that the issue arises because the ng-keydown is placed on the <td> tag, which means the function will only trigger when that element is currently focused. If you want to respond to key down events from anywhere on the page, you can achieve this by attaching the ng-keydown to the body tag instead of the <td>. Then, have the function broadcast an event that can be picked up by the sudoku component to execute the insertNum logic.

<body ng-keydown="onMyKeydownEvent($event)">

Next, define the function on the $rootScope in the run() block to broadcast the event.

app.run(function($rootScope) {
  $rootScope.onMyKeydownEvent = function(e) {
    $rootScope.$broadcast("MyKeydownEvent", e);
  };
});

Add a listener for this event in your component.

$scope.$on("MyKeydownEvent", function(e) {
  // InsertNum logic implementation goes here.
});

Please note that adjustments need to be made to some parts of the logic, such as utilizing e.currentTarget and updating variables like $scope.selectedCol = col; and $scope.selectedRow = row;. Instead, consider using the

ng-click="selectedCell(row, col)"

directly on the <td> tag to manage setting the necessary cell data in the scope for event handling.

What is the best way to capture ng-keypress/ $event when the user clicks outside of a div?

Answer №1

Similar questions

The screen reader seems to be malfunctioning as soon as I include this particular code

Creating a nested list component using an array of objects

What is the best way to create a visual separation between these two arrows using styled-components?

Verify user identity before sending directory in Express

Leveraging weather application programming interfaces

Exploring a new path with Angular

Learn a valuable trick to activate CSS animation using a button - simply click on the button and watch the animation start over each time

I am experiencing a lack of results when attempting to run db.find() in Mongodb

Is there a way to ensure that both new Date() and new Date("yyyy-mm-dd hh:mm:ss") are initialized with the same timezone?

Retrieve the data attribute from a select box that was created dynamically

Upon returning to the previous page, the checkbox remains checked and cannot be unchecked

Obtain the textfield whenever the user desires

Using AngularJS to Extract JSON Data from a Table in an HTML Document

AngularJS, building a hash of resources

When the web driver fails to function as expected

Tips on incorporating a parameter into an API call function within a React application

Using HTML5 video with cue points and stop points

I am encountering a problem with the app.patch() function not working properly. Although the get and delete functions are functioning as expected, the patch function seems to be

When a webpage is moved, the globalProperties variable of "vue3 typescript" is initialized to null

What is the best way to convert the data stored in an object to an array?