I have an input box and want to adjust the value when a key is pressed.
'keypress .comment-input': 'onCommentInputKeyBlur',
When a key is pressed, a class is added to the html element to reflect the changes.
onCommentInputKeyBlur: function(ev) {
var $form = $('#comment-submit');
if (ev.which) {
$form.addClass('focused');
} else if (!$(ev.currentTarget).val()) {
$form.removeClass('focused');
}
},
However, this doesn't detect special keys being pressed (ie when a user presses ctrl+v for a paste, it's not detected and the formatting is therefore wrong).
Using keyup and keydown halfway solve the problem, but formatting is wrong for a brief second:
Keydown -> the value isn't supposed to change until an actual value is entered through a keypress, but it changes right when ctrl is hit instead of waiting for the second key
Keyup -> new value is briefly pasted over the previous one while waiting for the key to actually be released.
Is there a better way to about solving this? Ideally, I would like to detect if the key entered does actually produce a value and is not simply a special key.
Look into the onchange event. It is fairly well supported and may solve your problem.
What is the ultimate goal of this functionality? perhaps there is a better approach.
If you insist on doing this via keypress event, then you can simply check event.keyCode and filter out the few keycodes that dont change anything, such as shift, control, alt.
Related
I'm reading through this section of the guide. I'm testing the complex component in the tutorial.
What I'm not understanding is why these two lines exist together, I believe only the first one should.
fillIn('.list-filter input', 'Seattle');
keyEvent('.list-filter input', 'keyup', 69);
In the first line, we fill in the input field which should automatically trigger a filtering of the results. Why are we adding an extra e to the field (keycode 69)? It's like we're going to search Seattlee (note the two e's at the end). Is the keyEvent method necessary to activate the triggering of the refresh but it actually doesn't print to the input field?
I suppose the keyup event doesn't enter a char. It simply does for its name stands for: fires the key up event. You can press a char on the keyboard and see, that the char is being added before you release the key. I'm sure this is specified somewhere, but I don't know this. My reason is the common sense.
So in order to trigger some functionality in that example, one needs not only to fill the field, but to fire a specific event, to which a js-handler is bound
I have been trying to deal with getting the last input in to a text field on an Android app from Javascript.
I was originally trying to use the KeyUp, KeyDown and KeyPress events to get the KeyCodes from keyboard input however with android soft keyboards you will get the KeyCode 229 for every key other than backspace, space and enter.
So now I am using the onInput event however this just seems to alert me to the fact that something has been input in to a text field and not what that input was.
document.getElementById("textarea").addEventListener("input", function (e) {
ClaroSpeak.KeyHandler(e);
}, false);
Does the input event some how let me know what the last change or key was, e.g. 'space' 'a' 'F' ect...
What about setting a 'global' variable and storing the last element in it?
I'm using jquery's function keypress for my input field
Now, let's say that I want to know when the user types a letter, if this is the first character in the field. I now use something like:
element.keypress(function(e){
//...
if(elementValue.length()==0){
//Do something
}
}
The problem is when the user selects the text that typed and then presses a key (lets say for the character 'A') that replaces it. Then this code returns the length of the old-(soon to be replaced) text.
I know that I could use keyup instead, but I think I need to stay with keypress because I have to do some checks for the pressed physical keys. (this answer really shows the difference between keyup and keypress in this case)
Any suggestions?
User Paul S. put me in the right direction...
That's what I have now and it works:
element.keypress(function(e){
//...
if(this.selectionStart==0){
//Do something
}
}
This way I detect when a key has been pressed while the caret was just at the beginning of the field.
Here's the problem, in abstract terms: i have three input fields (A, B, C). two of them need to be text inputs (A and B), the third is of irrelevant type. I need to enable the third if A is not empty and B is not empty. I need to disable C if A is empty or B is empty.
The code
// empty is the empty function from the phpjs project
// framework used: jQuery
// A, B and C are classes here
$(".A, .B").keypress(function(){
if( !empty($(".A").val()) && !empty($(".B").val()) )
$(".C").attr("disabled","");
else
$(".C").removeAttr("disabled");
});
I want to be able to check this on keypress, but when requesting the value of the input that is edited when the keypress event occurs i get the value that was calculated before the keypress event.
Has anybody stumbled upon this before and solved it?
have you tried using the keyUp event?
Use the keyup event instead.
Attach your handler to the keyrelease event. The value should have been updated by then.
use a combination of handlers for keyup and change. the keyup handler will update as the user types (excepting edge cases like holding a key down, which doesn't seem like a concern here) and the change handler will catch things like the user cutting the text with mouse actions before they can switch to field C. as an added measure you could add verification on field C's focus event, to make sure A and B really have something.
$('.A, .B').keydown(function(event) {
if(!empty($('.A').val()) && !empty($('.B').val()))
$(".C").attr("disabled","");
else
$(".C").removeAttr("disabled");
});
At the keypress event, the value of the INPUT is not yet set. Hence you can't easily know if it is empty.
While the keyup fires, the value of the INPUT is set.
But things get worse. The user can empty the field with the mouse or the Edit menu of the browser. In that case keyup is not fired.
In our web app we auto-save the values. Like in Mac OS, if you know, there is almost no save buttons.
To allow a reaction here is more or less what we do:
onfocus: a setInterval starts polling every 120ms or so, and checks the input for any change
if there is a change do the relevant action
onblur: a clearInterval stop the polling
$("#epFilter").keypress(function(){
query = $("#epFilter").val();
alert(query);
});
In this code, whenever I type in my text box, it always alert one character less. It doesn't catch the last character. Why?
Use the keyup event instead.
$("#epFilter").keyup(function(){
query = $("#epFilter").val();
alert(query);
});
keypress event is triggered when user presses a key, but before the character is inserted. Use keyup event instead.
Slightly improving Matt's answer (using this inside event handler):
$("#epFilter").keyup(function(){
query = $(this).val();
alert(query);
});
I wonder if that is a "normal" behavior. Shouldn't keypress be similar to keydown+keyup (except for the codes and keys)?
I had the same problem. I have an input-text field and I want to calculate a total on keypress. However, it does not change the total until I input again another character (this means when I entered the first digit it didn't update). I used "keyup" and was "fixed", but I think it could be better if I use keypress as it doesn't fire when I press other keys (like Ctrl, Shift, arrows, etc).
According to the documentation Keypress should work as I expected but for some reason it didn't.
This is not exactly an answer (so don't vote for it). Just my contribution.