Here is a way to do it: removing the datalist ID attribute.
First, declare the querySelector() methods.
var input = document.querySelector("#name"), // Selects the input.
datalist = document.querySelector("datalist"); // Selects the datalist.
Then declare the addEventListener method on the input element.
// Adds a keyup listener on the input.
input.addEventListener("keyup", (e) => {
// If input value is longer or equal than 2 chars, adding "users" on ID attribute.
if (e.target.value.length >= 2) {
datalist.setAttribute("id", "users");
} else {
datalist.setAttribute("id", "");
}
});
Explanation
When the input value has a length greater than or equal to 2, the setAttribute() method sets the datalist ID attribute to "users".
I set the operator to >= 2 and not >= 3. Here is why: the datalist dropdown element is triggered at each keypress.
The process goes like this:
length == 1 id="" - The drop down is not displayed, no ID is linked to the datalist;length == 2 id="users" - The drop down is not displayed, then datalist has its ID set to "users";length == 3 id="users" - The drop down now reads that the ID is set to "users" and displays the drop down.
Cons
- Since the attribute is set when the input length is
>= 2, if the input length == 3, the attribute will be removed when the input length == 2, and the drop down will be hidden when the input length == 1.
- Since the drop down list is part of the
OS and is not a DOM
element, it cannot be styled (or hidden, in this case). This is why I
used the setAttribute() method to set or remove the ID.
Upgrade?
A great upgrade / perfect solution would be creating a dropdown in JS just under the input. The drop down would be DOM element, and you could style it the way you want. You could ealisy display it > 2 chars and hide it < 3 chars.
Snippet
var input = document.querySelector("#name"), // Selects the input.
datalist = document.querySelector("datalist"); // Selects the datalist.
// Adds a keyup listener on the input.
input.addEventListener("keyup", (e) => {
// If input value is larger or equal than 2 chars, adding "users" on ID attribute.
if (e.target.value.length >= 2) {
datalist.setAttribute("id", "users");
} else {
datalist.setAttribute("id", "");
}
});
// I had to include your doValidate() function otherwise I would get an error while validaing.
function doValidate() {};
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>reading json</title>
<script type="text/javascript">function log(p) {return console.log(p)}</script>
</head>
<body>
<form name="form" class="form-container" method="post" onsubmit="return doValidate()" id="myForm2">
<label><input placeholder="Organisator" id="name" list="users" name="mitarbeiter" autocomplete='off' required /></label>
<datalist id="users" class="dle">
<option value="alicia@keys.com">Alicia Keys</option>
<option value="alicia@keyssecond.com">Alicia The Second</option>
<option value="john@doe.com">John Doe</option>
<option value="martin@scorsese.com">Martin Scorsese</option>
<option value="iron@man.com">Iron Man</option>
</datalist><br><br>
von <input type="time" name="zeitstart" class="zeitangaben" id="startzeitid"> Uhr bis <input type="time" name="zeitende" id="endzeitid" class="zeitangaben"> Uhr <br><br>
<button type="submit" class="btn" name="submit">Reservierung erstellen</button>
<button type="reset" class="btn cancel" onclick="hideDiv()">Abbrechen</button>
</form>
</body>
</html>
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