Trigger a keyup event function on meeting a certain condition in vanilla javascript-CodePudding

I have a piece of code where the user when he/she presses NumpadEnter key, a certain function triggers:

document.addEventListener("keyup", function(event) {
    if (event.code === "NumpadEnter") {   
         //some logic here    
    }
}

Now I want to trigger this keyup function when a certain condition is met:

if(flag == true){
    //trigger the keyup listener
}

How do I do that?

CodePudding user response：

Don't trigger the event. Instead place the logic in a separate function that both the event handler and the other code will call:

function performAction() {
   // logic here
}

document.addEventListener("keyup", function(event) {
    if (event.code === "NumpadEnter") {   
         performAction(); 
    }
}

// Now I want to trigger this keyup function when a certain condition is met:

if (flag == true){
    performAction();
}

CodePudding user response：

Put the keyup listener inside the flag checker. Then, pass a function to handle the event. Have that function as show here:

function handleEvent(event) {
    if (event.code === "NumpadEnter") {   
         //some logic here    
    }
}

if(flag == true){
    //trigger the keyup listener
document.addEventListener("keyup", handleEvent)
}