'addEventListener for input not working anymore after validation error is thrown
The problem
I use a form on a webpage where users fill in all sorts of details. There are 3 fields which generate the input for another field. That field gets generated like this: Firstname + Lastname + Date of birth. However, when a validation error is thrown on the form and the page reloads, the generated input isn't the expected format anymore. Only the Date of birth is then in that input.
It looks like it isn't initializing the Firstname + Lastname field anymore after a validation error is thrown on the page. Any suggestions on how to make it so that the fields gets initialized constantly? Or is there maybe a better way to handle this?
This is the code I use for the generated input
window.onload = function() {
let studentNoField = document.getElementById('input_7_9');
let enteredDetails = {
name: '',
lastname: '',
date: ''
};
/* set value in the third input: Studentnummer */
function generateInput() {
let studentNumber = Object.values(enteredDetails).join('').toLowerCase();
studentNoField.value = studentNumber;
}
/* event listener for first input: Voornaam */
document.getElementById('input_7_1').addEventListener('input', function(event) {
enteredDetails.name = event.target.value.replace(/\s/g, '').slice(0, 8);
generateInput();
});
/* event listener for second input: Achternaam */
document.getElementById('input_7_25').addEventListener('input', function(event) {
enteredDetails.lastname = event.target.value.replace(/\s/g, '').slice(0, 8);
generateInput();
});
/* event listener for second input: Date */
document.getElementById('input_7_3').addEventListener('input', function(event) {
enteredDetails.date = event.target.value.replace(/-/g, '').slice(0, 4);
generateInput();
});
/* Get selected training and format it properly for the PDF */
jQuery('#input_7_23').change(function(e) {
var optionChange = jQuery('#input_7_23 option:selected').text().toUpperCase();
jQuery('#input_7_58').val(optionChange);
});
}<html>
<body>
<form method="post" enctype="multipart/form-data" id="gform_7" action="/budget/" _lpchecked="1">
<div>
<div id="gform_fields_7">
<div id="field_7_9">
<label for="input_7_9">Studentnummer
<input name="input_9" id="input_7_9" type="text" value="" maxlength="20" aria-required="true" aria-invalid="false">
</div>
</div>
<div id="field_7_1">
<label for="input_7_1">Voornaam</label>
<div><input name="input_1" id="input_7_1" type="text" value="" aria-required="true" aria-invalid="false"> </div>
</div>
<div id="field_7_25">
<label for="input_7_25">Achternaam</label>
<div><input name="input_25" id="input_7_25" type="text" value="" aria-required="true" aria-invalid="false"> </div>
</div>
<div id="field_7_3">
<label for="input_7_3">Geboortedatum</label>
<div>
<input name="input_3" id="input_7_3" type="text" value="" placeholder="dd-mm-yyyy" aria-describedby="input_7_3_date_format" aria-invalid="false" aria-required="true">
<span id="input_7_3_date_format">DD dash MM dash JJJJ</span>
</div>
</div>
</div>
</div>
<div>
<input type="submit" id="gform_submit_button_7" value="Versturen" onclick="if(window["gf_submitting_7"]){return false;} window["gf_submitting_7"]=true; " onkeypress="if( event.keyCode == 13 ){ if(window["gf_submitting_7"]){return false;} window["gf_submitting_7"]=true; jQuery("#gform_7").trigger("submit",[true]); }">
</div>
</form>
</body>
</html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>Any help or suggestions is appreciated.
Solution 1:[1]
There were a few non-existing ids referenced in your code. In the following snippet I have tried to "correct" these errors, but I also went further: I removed all repetitions, thereby following the DRY principle "Don't repeat yourself". The "input"-event listener now works for all elements of the inps array. There is, however one differentiation: the first two elements are limited to 8 characters while the date is limited to 4: .slice(0,i<2?8:4).
const [stNr, ...inps]=[9, 1, 25, 3].map(n=> document.getElementById(`input_7_${n}`));
inps.forEach(inp=>inp.addEventListener("input",()=>
stNr.value=inps.map((el,i)=>
el.value.replace(/[\s-]/g,"").slice(0,i<2?8:4).toLowerCase()
).join(""))
)<form method="post" enctype="multipart/form-data" id="gform_7" action="/budget/" _lpchecked="1">
<div>
<div id="gform_fields_7">
<div id="field_7_9">
<label for="input_7_9">Studentnummer</label>
<input name="input_9" id="input_7_9" type="text" value="" maxlength="20" aria-required="true" aria-invalid="false">
</div>
</div>
<div id="field_7_1">
<label for="input_7_1">Voornaam</label>
<div><input name="input_1" id="input_7_1" type="text" value="" aria-required="true" aria-invalid="false"> </div>
</div>
<div id="field_7_25">
<label for="input_7_25">Achternaam</label>
<div><input name="input_25" id="input_7_25" type="text" value="" aria-required="true" aria-invalid="false"> </div>
</div>
<div id="field_7_3">
<label for="input_7_3">Geboortedatum</label>
<div>
<input name="input_3" id="input_7_3" type="text" value="" placeholder="dd-mm-yyyy" aria-describedby="input_7_3_date_format" aria-invalid="false" aria-required="true">
<span id="input_7_3_date_format">DD dash MM dash JJJJ</span>
</div>
</div>
</div>
</div>
<div>
<input type="submit" id="gform_submit_button_7" value="Versturen">
</div>
</form>I removed your jQuery statements at the end of your script, as they referred to non-existent ids. These statements can definitely also be re-written in Vanilla JS, if necessary.
And, as @CherryDT already mentioned: there is no validation code visible here. If it happens on the server then it is the server's responsibility to produce a suitable response that allows the client to render the page with the previously (possibly annotated) content.
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 |