Develop Reference

JS - Prevent append to be added multiple times

I have a form that has a mobile field. On submit button I put an event to add a value to the mobile field (it adds the country region code automatically which is a fixed value of "11"), so when the user clicks on Submit, the JS adds the "11" value to the mobile so the this field goes to the data base like this "1155555555" (the user just typed "55555555").
Ok, the problem is that if the user left an empty field (all fields are required), and clicks on Submit, the form won´t be sent but it will add the value "11" to the mobile field no matter what, and when the user fills up the empty field and click on Submit for the second time, it will add AGAIN the value "11", so the mobile goes like "111155555555", and so on and so forth.
Basically, what I need is to prevent this function from happening multiple times. It has to happen only once. How do I achieve this using JS?
HTML:
<input id="mobile" name="MOBILE" type="tel"><input type="number" value="11" id="front" class="hide">
<button type="submit" onclick="append11()">SUBMIT</button>
JS:
function append11(){
var mobilenumber = document.getElementById("mobile");
var front = document.getElementById("front").value;
mobilenumber.value=front+mobilenumber.value;
alert(mobilevalue.value);
}

Why you don't append the 11 in the function?
Like:
function append11(){
var mobilenumber = document.getElementById("mobile");
mobilenumber.value="11"+mobilenumber.value;
alert(mobilevalue.value);
}

I think you should heed the comment responses to your original question. Your approach has some risks.
But I'll assume you're a beginner who's just trying to learn how to do something like what you're asking about, so the javascript below applies a few principles you might consider.
function isNumberValid9(num) {
console.log(num, num.length);
//check string length and pattern
//this could be combined into a single regex, e.g.: mobileValue.match("^[0-9]{9}$")
var isValid9 = num.length === 9 && num.match("^[0-9]+$");
console.log(isValid9); //display the value about to be returned
return isValid9;
}
/* Conditionally prepend "11" */
function maybeAppend11() {
var mobilenumber = document.getElementById("mobile");
var mobileValue = mobilenumber.value;
//only prepend "11" if the number matches your expected pattern and length
if (isNumberValid9(mobileValue)) {
var front = document.getElementById("front").value;
mobilenumber.value = front + mobileValue;
}
alert(mobilenumber.value);
}
<input id="mobile" name="MOBILE" type="tel" value="555555555"><input type="number" value="11" id="front" class="hide">
<button type="submit" onclick="maybeAppend11()">SUBMIT</button>

How to hide certain characters within an html input list?

I have an html input list, with an associated datalist, defined as follows:
<input list="mylist" id="my-input" name="friend-name"
placeholder="Begin typing friend's name here..."
required class="form-control">
The list itself (and the associated datalist) is working fine. However, each of my entries are of the form: "String [numeric_id]"
What I am wondering is if there is any way that I can somehow hide
the [numeric_id] part before the form is submitted.
I have looked at the pattern attribute, but that seems to limit the
actual data allowed in the input, which isn't what I want - I just
want the part between square brackets [] to be hidden, but still
submitted to the form.
It would be ok to move it to another input of type=hidden as well.
Is there any possible way to do that?
#isherwood, here is my form tag:
<form action="/chat_forwarding/modal_edit_msg.php" id="fwd-form" method="POST" class="form-inline" style="display: block;">

If you're not using any framework that support binding, you should listen to input events and update a hidden input based on that.
This is a function that may give you the idea:
let realInput = document.getElementById('real-input');
let userInput = document.getElementById('user-input');
userInput.addEventListener('input', function(value) {
const inputValue = value.target.value;
realInput.value = inputValue; // update the hidden input
const userInputResult = inputValue.match(/\[[^\[]*\]/); // the regex for [numberic_id]
if (userInputResult) {
userInput.value = inputValue.substring(0, [userInputResult.index - 1]); // -1 is to remove the space between the 'string' and the '[numeric_id]'
}
});

I should have mentioned that my input is also using Awesomplete (and jQuery). For this reason, binding normal events like keyup did not work (the event would fire whenever a user typed a key). I was able to achieve the functionality I wanted with the awesomplete-selectcomplete event as follows (this will add a hidden input element with value of the id from a string of the form "String [id]"):
$("#my-input").on('awesomplete-selectcomplete',function(){
var fullStr = this.value;
//alert(fullStr);
var regex = /\[[0-9]+\]/g;
var match = regex.exec(fullStr);
//alert(match[0]);
if (match != null) // match found for [id]
{
var fullName = fullStr.substr(0,fullStr.lastIndexOf("[")-1);
var x = match[0];
var id = x.substr(1, x.lastIndexOf("]")-1);
//alert(id);
$('#fwd-form').prepend('<input type="hidden" name="h_uid" value="' + id + '">');
$('#my-input').val(fullName);
}
});

Partial Password Masking on Input Field

So I need to mask a SSN# input field, lets say the ssn is 123-45-6789, I need to display ***-**-6789 (real time as they enter each digit) but I still need to retain the original value to submit.
I got to the point where I can do that if the user strictly enters the value but it breaks if the user does anything else such as delete, or moving cursor to a random position and adds/deletes a number, copy pasting/deleting, etc. I really don't want to listen to a bunch of events to make this work if thats even possible.
I also tried having a div sit on top of the input field to display the masked ssn while the actual ssn was transparent/hidden behind it but again they lose the functionality of being able to add/delete/select delete/paste in random parts (other then when they start at the end) and also the cursor not totally in sync with the end of the ssn number (asterisk size was the issue). This also broke on some mobile browsers.
I also thought of having two separate input fields, one type password, and one type text sit right next to each other, but again highlighting and deleting/pasting between the two would be an issue.
Ideally if there was something out there to have an input field have two types, part of the value be type password and the rest be type text, that would be fantastic. Btw this is for react js app.
TLDR: Need a fully functional input field that will do password masking on only first 5 digits of ssn and be plaintext for last 4 digits (while having the full plaintext value available for submission).
Thanks!

This might be a little sloppy, but it works as you want it to, is all in one text field, returns the full accurate SSN (despite replacing first 5 values with bullet points), and allows for editing anywhere in the field.
<input type="password" id="ssn" maxlength=9 />
<script>
var ssn = document.getElementById('ssn');
ssn.addEventListener('input', ssnMask, false);
var ssnFirstFive = "";
var secondHalf = "";
var fullSSN = "";
function ssnMask(){
if (ssn.value.length <= 5){
ssn.type = 'password';
}
else{
detectChanges();
secondHalf = ssn.value.substring(5);
ssn.type = 'text';
ssn.value = "•••••";
ssn.value += secondHalf;
fullSSN = ssnFirstFive + secondHalf;
}
}
function detectChanges() {
for (var i = 0; i < 5; i++){
if (ssn.value[i] != "•"){
ssnFirstFive = ssnFirstFive.substring(0, i) + ssn.value[i] + ssnFirstFive.substring(i+1);
}
}
}
</script>
Essentially, every time the input is changed, it checks to see if it matches the first 5 from before, and if it doesn't, it will update the necessary characters.

You can use 3 different fields and make then password fields.
Add a focus handler that changes their type into text and a blur handler that changes them back to password.
You can combine them before submission or on the server.
#ssn1{width:25px;}
#ssn2{width:20px;}
#ssn3{width:35px;}
<input type="password" name="ssn" maxlength=3 id="ssn1" />
<input type="password" name="ssn" maxlength=2 id="ssn2"/>
<input type="password" name="ssn" maxlength=4 id="ssn3"/>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script>
$('[name="ssn"]').focus(function() {
$(this).attr("type", "text")
});
$('[name="ssn"]').blur(function() {
$(this).attr("type", "password")
});
</script>
You can also write a pass handler to all a full SSN to be pasted in the first field and have all three fields get set.
This is the closest you are going unless you work with a single full text box and give the user the ability to mask and unmask the field.
In production apps, this actually the approach I take:
Masked:
Unmasked:
You can implement you own focus/blur functions to automatically unmask/mask the field as needed.

Achieve this using html data attributes.
i have used the same html tag and store actual value in html tag attribute (data-value) to use later on and store value to display in html tag attribute value.
Function to partial mask input value
function mask_field_value(obj, mask_letters_count=7){
mask_value = $(this).data('mask-value') || '';
unmask_value = $(this).data('unmask-value') || '';
if (obj.value.length <= mask_letters_count){
obj.type = 'password';
mask_value = obj.value;
$(this).data('mask-value', obj.value);
} else {
obj.type = 'text';
unmask_value = obj.value.substring(mask_letters_count);
obj.value = "*".repeat(mask_letters_count) + unmask_value;
$(this).data('unmask-value', unmask_value);
}
$(this).data('value', mask_value + unmask_value);
console.log($(this).data('value'));
}
Add an event on input fields to mask
$(document).ready(function () {
$(document).on('keyup', '.mask_input_display', function () {
mask_field_value(this);
});
});

How do you return data from javascript into a html form?

I was wondering if anyone can help? What I am trying to do is retrieve the word count from javascript code into a form and then pass it into php along with the rest of the form which will check that the word count is a certain length or else it won't be submitted.
The javascript is as follows.
counter = function() {
var value = $('#msg').val();
if (value.length == 0) {
$('#wordCount').html(0);
$('#totalChars').html(0);
$('#charCount').html(0);
$('#charCountNoSpace').html(0);
return;
}
var regex = /\s+/gi;
var wordCount = value.trim().replace(regex, ' ').split(' ').length;
var totalChars = value.length;
var charCount = value.trim().length;
var charCountNoSpace = value.replace(regex, '').length;
$('#wordCount').html(wordCount);
$('#totalChars').html(totalChars);
$('#charCount').html(charCount);
$('#charCountNoSpace').html(charCountNoSpace);
};
$(document).ready(function() {
$('#count').click(counter);
$('#msg').change(counter);
$('#msg').keydown(counter);
$('#msg').keypress(counter);
$('#msg').keyup(counter);
$('#msg').blur(counter);
$('#msg').focus(counter);
});
My problem is returning wordCount into a hidden field in a form. I am not too good with javascript and am not sure how to modify this code to make it work. The rest I can figure out but am stuck here. Thank you for your help, it is greatly appreciated.

$('#wordCount').val(wordCount);
$('#totalChars').val(totalChars);
$('#charCount').val(charCount);
$('#charCountNoSpace').val(charCountNoSpace);
Use .val() instead of .html(), because .val() refers to the value of an input field.

Your HTML inside the form should include a hidden input field:
<input type="hidden" id="word_count" name="word_count" value="0" />
Then inside your JS:
$('#word_count').val(wordCount);
All together embedded inside your function:
counter = function() {
var value = $('#msg').val();
if (value.length == 0) {
$('#wordCount').html(0);
$('#totalChars').html(0);
$('#charCount').html(0);
$('#charCountNoSpace').html(0);
return;
}
var regex = /\s+/gi;
var wordCount = value.trim().replace(regex, ' ').split(' ').length;
var totalChars = value.length;
var charCount = value.trim().length;
var charCountNoSpace = value.replace(regex, '').length;
$('#wordCount').html(wordCount);
$('#word_count').val(wordCount);
$('#totalChars').html(totalChars);
$('#charCount').html(charCount);
$('#charCountNoSpace').html(charCountNoSpace);
};
$(document).ready(function() {
$('#count').click(counter);
$('#msg').change(counter);
$('#msg').keydown(counter);
$('#msg').keypress(counter);
$('#msg').keyup(counter);
$('#msg').blur(counter);
$('#msg').focus(counter);
});

If you have INPUT fields in your form, use val()
$('#wordCount').val(wordCount)
That would work for a field like this:
Be aware that there's a difference between "id" and "class". jQuery allows you to select elements based on their properties. The "id" property gets selected with "#", just like you'd do it in CSS. So make sure you have that "id='wordCount'" defined in your hidden field.

Have a look at this http://www.hscripts.com/scripts/JavaScript/word-count.php
There are plenty of examples online, just google "javascript count words in textbox"
Some imporntant notes:
A very long string with no spaces is still 1 word so don't forget to set the max length for fields
If you are doing this as a sort of validation be aware of the fact that you can not trust a form field because it can be easily manipulated, so don't forget to check the word count on the server side after the form is submitted.

The Code that you are showing is not just javascript it also includes jquery, please make sure you included jquery
<script src = "http://code.jquery.com/jquery-1.11.1.min.js"></script>
$('#field').val('asdf'); //Sets Value of a input type="text"
$('#field').html('sadf'); //Sets the html of a div
Using javascript you use either value for a input or innerHtml for a div or other text based element
document.getElementById('field').value = 'asdfsadf';
document.getElementById('field').innerHtml= 'asdfsadf';
Also instead of using a form submit consider using jquery $.ajax(there is nothing wrong with form submits but there are benefits to knowing jquery as well such as you came make async requests
http://api.jquery.com/jquery.ajax/
You will want to use a hidden field such as the following and have it in the form
<form id="myform" action='posttome.php'>
<input type="hidden" id="wordCount"/>
<input type="submit" value="sbumit"> //Submits Form
</form>
Then set its value by using of of three methods, a an elements html, an elements value, or a javascript variable $('#wordCount').val()
$('#wordCount').val($('#wordCountSoruceDiv').html()); // Sets the value to another divs html
$('#wordCount').val($('#wordCountSourceInput').val()); // Sets the value to another inputs value
$('#wordCount').val(wordCountVariable); // Sets the value to a variable

Javascript: Field validation

so i have been looking all over the internet for some simple javascript code that will let me give an alert when a field is empty and a different one when a # is not present. I keep finding regex, html and different plugins. I however need to do this in pure Javascript code. Any ideas how this could be done in a simple way?
And please, if you think this question doesn't belong here or is stupid, please point me to somewhere where i can find this information instead of insulting me. I have little to no experience with javascript.
function test(email, name) {
}

Here if you want to validate Email, use following code with given regex :
<input type="text" name="email" id="emailId" value="" >
<button onclick = "return ValidateEmail(document.getElementById('emailId').value)">Validate</button>
<script>
function ValidateEmail(inputText){
var mailformat = /^\w+([\.-]?\w+)*#\w+([\.-]?\w+)*(\.\w{2,3})+$/;
if(inputText.match(mailformat)) {
return true;
}
else {
alert("You have entered an invalid email address!");
return false;
}
}
</script>
Or if you want to check the empty field, use following :
if(trim(document.getElementById('emailId').value)== ""){
alert("Field is empty")
}
// For #
var textVal = document.getElementById('emailId').value
if(textVal.indexOf("#") == -1){
alert(" # doesn't exist in input value");
}
Here is the fiddle : http://jsfiddle.net/TgNC5/

You have to find an object of element you want check (textbox etc).
<input type="text" name="email" id="email" />
In JS:
if(document.getElementById("email").value == "") { // test if it is empty
alert("E-mail empty");
}
This is really basic. Using regexp you can test, if it is real e-mail, or some garbage. I recommend reading something about JS and HTML.

function test_email(field_id, field_size) {
var field_value = $('#'+field_id+'').val();
error = false;
var pattern=/^([\w-\.]+)#((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$/;
if(!pattern.test(field_value)){
error = true;
$('#'+field_id+'').attr('class','error_email');
}
return error;
}

This will check for empty string as well as for # symbol:
if(a=="")
alert("a is empty");
else if(a.indexOf("#")<0)
alert("a does not contain #");

You can do something like this:
var input = document.getElementById('email');
input.onblur = function() {
var value = input.value
if (value == "") {
alert("empty");
}
if (value.indexOf("#") == -1) {
alert("No # symbol");
}
}
see fiddle
Although this is not a solid soltuion for checking email addresses, please see the references below for a more detailed solution:
http://www.regular-expressions.info/email.html
http://www.codeproject.com/Tips/492632/Email-Validation-in-JavaScript
---- UPDATE ----
I have been made aware that there is no IE available to target, so the input field needs to be targeted like so:
document.getElementsByTagName("input")
Using this code will select all input fields present on the page. This is not what are looking for, we want to target a specific input field. The only way to do this without a class or ID is to selected it by key, like so:
document.getElementsByTagName("input")[0]
Without seeing all of your HTML it is impossible for me to know the correct key to use so you will need to count the amount of input fields on the page and the location of which your input field exists.
1st input filed = document.getElementsByTagName("input")[0]
2nd input filed = document.getElementsByTagName("input")[1]
3rd input filed = document.getElementsByTagName("input")[2]
4th input filed = document.getElementsByTagName("input")[3]
etc...
Hope this helps.