How would you, with JS or jQuery, determine if what the user is typing is a new word?
What I want to do:
I am writing a documentation tool with autocompletion for different types. If you type f.e. # it will populate Java Classes in a box, # would populate test classes, etc. Now I don't want to populate these values, if the user is writing something like an email like yourname#domain.com. So I need the values to populate only when it's the beginning of the word.
I am aware of keydown, keyup events, etc. I just don't know how to check for this certain kind of event properly.
One way would be to save every typed letter in a variable and then check if the previous "letter" was a space and if it was, we know it's a new word. Is this the best/most efficient way to do this?
One way is to check what's before the # in the input box, using selectionStart:
onload = function() {
var io = document.getElementById("io");
io.onkeypress = function(e) {
if(e.charCode == 64 && (
io.selectionStart == 0 || io.value[io.selectionStart-1].match(/\s/)))
document.getElementById("ac").innerHTML = "autocomplete!";
else
document.getElementById("ac").innerHTML = "";
}
}
<input id="io">
<div id="ac"></div>
Try this JSFiddle. I'm performing the check like so:
var text = $("#test").val();
if (text.length == 0 || text.charAt(text.length - 1).match(/[\s\b]/)) {
$("#result").html("new word");
} else {
$("#result").html("no new word");
}
You can easily adapt the .match() pattern if you like to include other characters as "whitespaces" (e.g. curly braces) for your Editor.
Assuming text is entered in a text input with id="txtchangedetection":
$("#txtchangedetection").change(function(){
console.log("The text has been changed.");
});
/*This is `JQuery`*/
I've understood you want to detect word changes in the input. Please precise if I'm wrong. What do you mean by 'new word' ?
One solution will be like this :
1- declare a variable "newWord = true"
2- with keydown event check if the key pressed is a space
if YES : newWord = true
if NO : newWord = false
var newWord=true;
$("#textarea").keydown(function(e){
if(e.keyCode == 32){
newWord=true;
}else{
newWord=false;
switch(e.keyCode){
//work to do
}
}
})
use keypress on your input field... populate the array inside the if with your special chars
if(prev == 13 || prev == 32 || $('#doc').val().length==0 || prev==null){
listen = true;
}else{
listen = false;
}
prev = e.which;
if(listen && $.inArray(String.fromCharCode(e.which),["#","#"]) != -1){
e.preventDefault();
alert("populate box here");
listen = false;
prev = null;
}
the fiddle https://jsfiddle.net/6okfqub4/
Related
Intended outcome: The user inputs any characters from the keyboard. They will then be used to check if the inputted string is a word from the Dictionary API. If they match with each other, the string will be in the <p> element. If not, then the inputted string will go through anotherFunction().
Questions:
Is it possible by keyboard.event, but not in the <input> / <textarea>, for the fetchApi() to be able to search for a real word from a string, instead of each inputted character? (Like I do not want that only until the user types the word and press Enter, then the API starts kicking in)
If so, what can I change in the code in order to get the above intended outcome?
Thank you again, and again. Thanks a lot!
var characters = '';
var text = document.getElementById("text");
var word = result[arg0].word;
document.addEventListener('keydown', function(input) {
if (input.key >= 'a' && input.key <= 'z') {
fetchApi(input.key);
}
});
function fetchApi(word) {
let url = `https://api.dictionaryapi.dev/api/v2/entries/en/${word}`;
fetch(url).then(res => res.json()).then(result => data(result, word));
}
function data(result, word) {
if (input.key == word) {
characters += input.key;
text.innerHTML = characters;
}
else {
text.innerHTML = anotherFunction();
}
}
<p id="text"></p>
I hope I understand your question right but I think what you want is:
Only listen for key events in the input field instead of the entire document. For this simply add the event listener to the desired <input> or <textarea> instead of the document. Explained here
text.addEventListener('keydown', function(input) {
if (input.key >= 'a' && input.key <= 'z') {
fetchApi(input.key);
}
});
You can also listen for the Enter key. For this you could either simply get the value of the <input> and send it directly to the API (text.value). Or if you want to filter the characters before (and change as little code as possible from your existing solution) you could also send your characters string to it. (Like the code below)
let inputWord = ""
text.addEventListener('keydown', function(input) {
if (input.key >= 'a' && input.key <= 'z') {
inputWord += input.key; // add each character to string if it's between a-z
} else if (input.key === "Enter") { // on enter fetch the entire inputWord
fetchApi(inputWord);
inputWord = "" // clear inputWord after Enter (but not in <input>)
}
});
In my textbox I allowed only integer value and comma it will control using javascript.Now my doubt how to control more than comma continuously (i.e)1,2,3,4 is to ok then 1,2,3,,4,,5 its need restricted.Its possible in javascript.
<p:inputText onKeyPress="onlyAllowDigitComma(event);"/>
Your answer doesn't show how far you go with your solution. I suppose code bellow is what you wanted, also I suppose you need removing comas from start and end.
<input type="text" onkeypress="onlyAllowDigitComma(event,this);" onkeyup="onlyAllowDigitComma(event,this);"/>
<script>
function onlyAllowDigitComma(e,l){
var k = e.which;
if ((k <= 47 || k >= 58 ) && k!=44 && k!=8 && k!=0) {
e.preventDefault()
};
l.value=l.value.replace(/,,/g,',');
}
</script>
Use a regex to validate your input. If the first match you get is the same as the whole input, then you're good to go.
The regex you're looking for is /(\d,?)*/g (Test Link)
For the sake of simplicity, I did the following code with the 'keyup' event to avoid shortcuts problems. You may also want to check on copy / paste event.
let myInput = document.getElementById('myInput');
let myInputValue = myInput.value;
myInput.addEventListener('keyup', function(event){
if(isPerfectMatch(myInput.value, /(\d,?)*/g)){
console.log('Format is correct.');
myInputValue = myInput.value;
}
else {
console.log('Wrong format');
myInput.value = myInputValue;
}
});
function isPerfectMatch(value, regex){
let match = value.match(regex);
return match !== null && match[0] == value;
}
(Demo JSFiddle)
I have received PHP/JS code from previous developer and I need to add number validation to a Mobile Number field. I already have the HTML validation in place but I need to add that if someone presses an invalid key, that it doesn't get displayed only to highlight the field later in red because it contains invalid input.
I've seen many regex's used and tried them but they had an either/or effect from what I need which is: If a letter or special character is entered, do not accept and do not display, all other input (digits, keys) is accepted (I need the invalid character not be displayed at all, not displayed and then erased). The regex that is working the most now is this:
function filterNonDigits(evt)
{
var event = evt || window.event;
var keyentered = event.keyCode || event.which;
keyentered = String.fromCharCode(keyentered);
//var regex1 = /[0-9]|\./;
var regex2 = /^[a-zA-Z.,;:|\\\/~!##$%^&*_-{}\[\]()`"'<>?\s]+$/;
if( regex2.test(keyentered) ) {
event.returnValue = false;
if(event.preventDefault) event.preventDefault();
}
When I used the commented regex1 (with the IF condition reversed), naturally it limited input to only digits thus preventing all keys such as Delete, BackSpace, etc. When using regex2, I still can't press Delete or the digits from the numpad.
So my question is, can the above code be modified to accept only digits but also allow keys? Another important point is that I need a method that doesn't use keycodes (8, 24 etc) for those key, in order to make sure all keyboard types can be used.
New Update:
So my solution is as follows: If the "oninput" property exists, I use the solution provided by Ehtesham and if it doesn't, the backup uses the solution provided by Rohan Kumar. So it's something like this:
if (obj.hasOwnProperty('oninput') || ('oninput' in obj))
{
$('#mobileno').on('input', function (event) {
this.value = this.value.replace(/[^0-9]/g, '');
});
}
else
{
$('#mobileno').on('keypress',function(e){
var deleteCode = 8; var backspaceCode = 46;
var key = e.which;
if ((key>=48 && key<=57) || key === deleteCode || key === backspaceCode || (key>=37 && key<=40) || key===0)
{
character = String.fromCharCode(key);
if( character != '.' && character != '%' && character != '&' && character != '(' && character != '\'' )
{
return true;
}
else { return false; }
}
else { return false; }
});
}
Thanks.
The best method here is to use input event which handles all your concerns. It is supported in all modern browsers. With jQuery you can do like following. Handles all cases pasting the value with mouse/keyboard backspace etc.
$('.numeric').on('input', function (event) {
this.value = this.value.replace(/[^0-9]/g, '');
});
See it here
You can check if input event is supported by checking if the input has this property if not you can use onkeyup for older browsers.
if (inputElement.hasOwnProperty('oninput')) {
// bind input
} else {
// bind onkeyup
}
A nice solution is described in a previous post:
jQuery('.numbersOnly').keyup(function () {
this.value = this.value.replace(/[^0-9\.]/g,'');
});
Try it like,
CSS
.error{border:1px solid #F00;}
SCRIPT
$('#key').on('keydown',function(e){
var deleteKeyCode = 8;
var backspaceKeyCode = 46;
if ((e.which>=48 && e.which<=57) ||
(e.which>=96 && e.which<=105) || // for num pad numeric keys
e.which === deleteKeyCode || // for delete key,
e.which === backspaceKeyCode) // for backspace
// you can add code for left,right arrow keys
{
$(this).removeClass('error');
return true;
}
else
{
$(this).addClass('error');
return false;
}
});
Fiddle: http://jsfiddle.net/PueS2/
Instead of checking for the event keyCode, why don't you just check for changes inside the actual input and then filter out non-numbers?
This example uses keyup so that it can read what was actually entered, which means the character is briefly displayed and then removed, but hopefully you get my gist. It might even give the user feedback that the character is not allowed. Either way I think this is the easiest setup, let me know if you need more help fleshing this out.
function filterNonDigits(evt)
{
var event = evt || window.event;
var val = event.target.value;
var filtered = val.replace(/[^0-9]/g, '');
if(filtered !== val) {
event.target.value = filtered;
event.target.className += " error";
}
}
http://jsfiddle.net/mEvSV/1/
(jquery used solely to easily bind the keyup function, you won't need it for your actual script)
/\d/ is equivalent to the above described /[0-9]/. src: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions#special-digit
This is a bit more concise...
this.value = this.value.replace(/\D/gm, '');
For example we have a textbox which is for tags for a blog. What I want is I want to limit number of tags to be limited.
For instance, "web hosting,php,windows8".
When the user tries to type another one to textbox which he will start with comma, the textbox won't let him write it.
In your keypress handler, capture the event object and do;
if (event.which == 44 && $(this).val().split(",").length > 2) {
event.preventDefault();
}
See it in action here; http://jsfiddle.net/5L7mU/
We can split this problem into 3 smaller problems.
First, we need a way to stop the user from writing stuff into the textbox. When you hook a callback on keypress, the event passed has a method called preventDefault which should do the job. So to block all input:
$("input").keypress(function(event) {
event.preventDefault();
});
Now, to check how many comas there already are in the textbox, we can use regex. The match function will return null instead of an empty array if there are no matches so we gotta check for that.
$("input").keypress(function(event) {
var matches = $(this).val().match(/,/g);
var count = 0;
if (matches)
count = matches.length;
console.log(count);
});
Finally, we need to be able to check if the user typed in a coma. The event objectwill have a property called which that contains the key code of the character entered. With a little bit of exploring, you can find out that the key code for coma is 44.
$("input").keypress(function(event) {
if (event.which == 44)
event.preventDefault();
});
So if we put it all together:
$("input").keypress(function(event) {
var matches = $(this).val().match(/,/g);
var count = 0;
if (matches)
count = matches.length;
if (count >= 2 && event.which == 44)
event.preventDefault();
});
http://jsfiddle.net/4wn5W/
$(document).ready(function(){
$('#textbox').keypress(function(e){
var text = $(this).val();
if(text.split(',').length>3){
return false;
}else if(e.which==44&&text.split(',').length>2){
return false
}
});
});
Fiddle:
http://jsfiddle.net/L4X4C/
i have this code for counting how many digits where entered
var tnnod=0;
function telephone(e) {
if (tnnod<10) {
var key;
var keychar;
if (window.event) {
key = window.event.keyCode;
}
else if (e) {
key = e.which;
}
else {
return true;
}
keychar = String.fromCharCode(key);
if ((key==null) || (key==0) || (key==8) || (key==9) || (key==13) || (key==27) ) {
return true;
}
else if ((("0123456789").indexOf(keychar) > -1)) {
tnnod+=1;
return true;
}
else if (keychar == "-") {
return true;
}
else
return false;
}
else
return false
}
but how do i remove 1 from the counter each time the backspace was hitted and the char that was deleted was a digit and not "-"
i have tried getting the key == 8 to do something but hitting the backspace doesn't really return anything for some reason
what can be the problem?
You don't have to detect specifically the backspace keypress. Try this:
var tn_count = 0;
function telephone(ev) {
var el = document.getElementById("telephone_number");
if(tn_count < 10) {
var key, keychar;
if(window.event) {
key = window.event.keyCode;
} else {
key = ev.which;
}
keychar = String.fromCharCode(key);
}
if(!keychar.match(/\d|-/)) { // only allow digits or "-"
return false;
}
// clean up any non-digit chars that get in here somehow
el.value = el.value.replace(/[A-Za-z]+/, '');
tn_count = el.value.replace("-",'').length; // get the digit length
return true;
}
The basic difference here is that instead of adding 1 every time the key is pressed, just updated tn_count to be the total count of all digit characters in the field. You can probably do some more cleanup just to be safe, but this should get you started.
I think it's a bad idea to count keystrokes for something like that. We're talking about input into a text field, right? What will you do if the user does a paste of some string from the clipboard? What if he uses the mouse to mark some text and delete it? Replace it with one character?
I think it would make a lot more sense to just look at the text from the text field and (if necessary) do some fiddling to ensure proper syntax. Let the user enter whatever he wants, if you find garbage characters you can just replace the text with one that doesn't have those characters. You can also trim the field at this time (no leading or trailing spaces). Also, keeping accurate track of the length becomes as easy as asking for the length of the string returned from the field.
A few thoughts -
Would it be possible to use 3 fields instead of 1? Then you could add the dashes later.
If you want to use your current method, you might keep a counter of the dashes that have been typed. Then, on each key stroke, check to see how many dashes are left. If it's different than the previous count, you know they've deleted the dashes.
I think it needs to be a bit more robust. What if they put a dash in an odd place within the string?
You could also prevent the user from entering all non-numeric characters and insert the dashes at each point of separation. So, insert a dash after 3 and 6 numbers as they are typing.
Could you just count the length of the string and use that value? Something like the following:
function getLen(el) {
return el.value.replace('-', '').length;
}
alert(getLen(document.getElementById('telephone_number')));