hello message function in js [duplicate] - javascript

I am new to javascript and on every simple thing i get some kind of problem but this seems un-solve-able to me. I googled and nothing simillar.
After i input data into textbox and store it into variable, i print out variable in paragraph.
Problem is that output i printed out disappears within less than second. Code seems to be normal, what might it be? It looks like c when you dont put getch();
Thanks in advance.
<form>Unesite broj koji ce se ispisat kasnije.<br>
<input type="text" id="userInput">
<input type="submit" name="unos" value="Unesi i ispisi" onclick="unesi()"><br><br>
</form>
<br><br>
<p>Unjeli ste <b id="ispis"></b></p>
<script>
function unesi(){
var userInput = document.getElementById('userInput').value;
document.getElementById('ispis').innerHTML = userInput;
}
</script>

The <form> tag doesn't specify an action attribute, so when you click the submit button, the browser will submit the form to the current URL - which will look a lot like the page is refreshing.
If you want to run the unesi function when the user clicks submit and prevent the HTML form from submitting, you need to change it slightly:
<input type="submit" name="unos" value="Unesi i ispisi"
onclick="unesi(); return false;">
The return false prevents the form from submitting itself.

Because the form submits and refreshes the page. Cancel the form request.
<input type="submit" name="unos" value="Unesi i ispisi" onclick="return unesi()">
and the function
function unesi(){
var userInput = document.getElementById('userInput').value;
document.getElementById('ispis').innerHTML = userInput;
return false;
}
better option is to do it on the form level
<form action="#" method="get" onsubmit="return unesi()">

Instead of cancelling the form submitting, another option is to change
<input type="submit" name="unos" value="Unesi i ispisi" onclick="unesi()">
to
<input type="button" name="unos" value="Unesi i ispisi" onclick="unesi()">
This will make it so the form does not try to submit at all when the button is pressed.

Related

How to embed form data in the action link?

I have a form defined:
<form method="post">
<label for="phone_or_uid">Enter a phone number or uid:</label>
<input type="text" name="phone_or_uid" value=""></input>
<input type="submit" name="" value="Submit"></input>
</form>
Currently, when this form is submitted I am able to work with the data and add info to the page based on the value of phone_or_uid. However, what I'd like to do is something where the form redirects to the same page but with the value of phone_or_uid appended to the end. So, if the initial page is https://myhost.com/lookup then submitting the form should bring the user to https://myhost.com/lookup/16175431234 if the value of the phone_or_uid input box is 16175431234.
Essentially, my form should then look something like this:
<form action={some code that puts the value of phone_or_uid here}>
...
</form>
Is this possible? And if so, how could I accomplish this? I don't want to create or redirect to any extra files, if possible.
I would use JavaScript. Listen for the submit event and redirect to a custom url.
this is just a really general example:
<form method="post" onsubmit="submitFunction()">
<label for="phone_or_uid">Enter a phone number or uid:</label>
<input type="text" name="phone_or_uid" id="phone_or_uid" value=""></input>
<input type="submit" name="" value="Submit"></input>
</form>
<script>
submitFunction = (event) => {
event.preventDefault();
const phoneInfo = document.getElementById('phone_or_uid').value;
fetch('http://myhost.com/lookup/' + phoneInfo, {
method: 'post'
})
.then(response => {
window.location.href = "http://myhost.com/lookup/' + phoneInfo";
});
}
</script>

After submit, input text disappears and reload the page(AJAX)

Why my page reloads even I used ajax to it and it also disappears my input text after clicking the submit button. I already used show to solve it but it doesn't work.
<form method="POST" action="<?php $_SERVER['PHP_SELF'];?>">
<input type="text" name="name" id="name">
<span id="namenotif" style="color:red;"> <span>
<br>
<input type="text" name="price" id="price">
<span id="pricenotif" style="color:red;"> <span>
<br>
<input type="submit" name="submit" id="save"><br>
</form>
<script>
$(document).ready(function() {
$(document).on("click","#save",function(){
var name = $("#name").val();
var price = $("#price").val();
if(name==""){
$("#namenotif").html("Enter a name");
$("#name").show("fast");
$("#save").show("fast");
}
else if(price==""){
$("#pricenotif").html("Enter a price");
$("#price").show("fast");
$("#save").show("fast");
}else{
$.ajax({
url:"addproduct.php",
type:"POST",
data:{name:name,price:price},
success:function(data){
alert("Successful");
}
});
}
});
});
</script>
add return false to end of function, that handle click event
Two solutions:
Change the button type='submit' to type='button'
or ( and preferably )
Change the event listener to listen for the form's onSumbit event then call event.preventDefault or in jQuery, I think you just do return false in the callback.
The form is being submitted I think, because it is the default behavior of submit button to submit the form, no matter if you used ajax or not. so you can prevent the default behavior by simple adding a code in jquery. Modify the code like this:
$(document).on("click","#save",function(e){
e.preventDefault();
...............
Rest of the codes can remain same. so only prevent the default action, it should work.
Its because of type="submit"
Use
<input type="button" name="submit" id="save"><br>
Or
<a href="javascript:void(0) id="save">
or
jquery's preventDefault();

Javascript innerHTML Not Posting

I am trying to get a function to print out whatever the user inputs into the text-box. I am using onClick as an attribute on my submit button. I know I set it up properly because it flickers the answer, but only for a split second. How can I get the input to stay on the page? Here's the code: HTML: Type what you want to post to the website!
HTML:
<div id="main_div">
<section id="leftbox">
<form name="mybox">
Type what you want to post to the website!:
<br />
<input type="textbox" size="15" maxlength="15" name="text" id="text">
<br />
<input type="submit" value="Submit!" onClick="doFirst()">
</form>
</section>
</div>
<div id="insert"></div>
Javascript:
function doFirst(){
text = document.getElementById('text');
insert = document.getElementById('insert');
if(text.value == "")
{
insert.innerHTML = "Please input something!";
return false;
}
else
{
insert.innerHTML = text.value;
}
}
try this:
Using type=button
<input type="button" value="Submit!" onClick="doFirst()">
OR using type=submit
<form name="mybox" onsubmit="doFirst(); return false;">
<input type="submit" value="Submit!">
</form>
Explain:
The action for onclick in submit button DO executed. You keep see the page does not have any changes, because of there are a FORM. And the key point: the form handle the submit action after the JS function doFirst() immediately. Adding the onsubmit in the form with return false to stop default action, means:
<form name="mybox" onsubmit="return false;">
<input type="button" value="Submit!" onClick="doFirst()">
</form>
To simplify the changes, use button instead of submit type, or using onsubmit instead of onclick in form trigger.
onClick="doFirst()"
gets converted into an anonymous function:
function(){ doFirst() }
and whatever that function returns determines if the submit should be completed or aborted, so you should use:
onClick="return doFirst();"
In other words, it's not enough that doFirst return something, whatever doFirst returns should be returned again inside the onClick.

Add text to parameter before sumbit form

I have a form like this
<form action="http://example.com/search" method="get">
<input type="text" name="q">
<input type="submit">
</form>
When I fill parameter q with some text (e.g. 'AAAAA') and submit this form, the url become to http://example.com/search?q=AAAAA.
But, I want add some text to parameter q with other text before submit. For example, if user input 'AAAAA' the parameter become 'AAAAA BBBBB CCCCC'. So the url become to http://example.com/search?q=AAAAA+BBBBB+CCCCC.
Use JavaScript to modify the value before submit. Add an onsubmit event to the form which will get fired when you submit the button. Like this...
<form action="http://example.com/search" method="get" onsubmit="return addText();">
<input type="text" name="q" id="q">
<input type="submit">
</form>
<script>
function addText(){
document.getElementById("q").value += " BBBB CCCC"; // Whatever your value is
return true;
}
</script>
Watch my example on jsFiddle http://jsfiddle.net/ilya_kolodnik/N9gWm/
var text_to_append = "test";
$('form').submit(function(obj) {
obj.preventDefault();
alert($("input[name='q']").val());
$("input[name='q']").val($("input[name='q']").val() + text_to_append);
this.submit();
});
At first we handle 'submit' action on form. To prevent form submit we use preventDefault(); Than we modify our query and submit the form.

using javascript to modify form action submits form without doing submit

I have an HTML form that I submit after changing the action with some javascript. Two different buttons can do the submit.
The interesting thing is that I was trying to debug it and inserted an alert after changing the action and before submitting the form. The form is submitted without the alert ever being displayed. To make sure it's actually performing the javascript, I added an alert before changing the action. That alert displays; the alert after changing the action does not.
<form name='FormSelect' method='post' action='Undefined'>
...
<button onclick="SubmitForm('class')">Submit</button>
...
<button onclick="SubmitForm('student')">Submit</button>
...
</form>
<script type="text/javascript">
function SubmitForm(target){
alert("Action 1: " + document.FormSelect.action);
if (target=="class") {
document.FormSelect.action = "ClassAction.php";
} else {
document.FormSelect.action = "StudentAction.php";
}
alert("Action 2: " + document.FormSelect.action);
// document.FormSelect.submit();
}
</script>
Is that the expected sequence of events?
Any button placed inside form element will cause submit action. To prevent this you can add type="button" to button elements, or make you submit callback return false;
<button type="button" onclick="SubmitForm('class')">Submit</button
see http://jsfiddle.net/yD2Uu/
As the others have already pointed out the form will be submitted anyway if you don't cancle the event. I want to suggest a JavaScript free solution to your problem.
<button formaction="ClassAction.php">Submit</button>
<button formaction="StudentAction.php">Submit</button>
It's not supported in IE < 10 though. But you can still use your function as a fallback then, just a bit more elegant ;)
function SubmitForm(button){
button.form.action = button.formaction;
}
A better solution is to give the buttons a name each and submit to Action.php and let the server get the value of the named button
$student = filter_var($_POST["student"], FILTER_SANITIZE_STRING); // php5 cleaning
when you have
<form method="post" action="Actions.php">
<input type="submit" name="student" value="John Doe" />
<input type="submit" name="student" value="Jane Doe" />
<input type="submit" name="student" value="Whatever Doe" />
</form>
Otherwise if you must
Try this
<form method='post' action='Undefined'>
...
<input type="button" value="Class" onclick="SubmitForm(this)" />
...
<input type="button" value="Student" onclick="SubmitForm(this)"/>
...
</form>
<script type="text/javascript">
var actions = {
"class":"ClassAction.php",
"student":"StudentAction.php"
}
function SubmitForm(button){
button.form.action = actions[button.value];
button.form.submit();
}
</script>
Thanks to Yauhen Vasileusky's example, I started removing code between my 1st & 2nd alerts and found that the problem seems to be the following IF statement:
if (document.FormSelect.FormName.value.substr(0,19)=="ObservationRequest_" || document.FormSelect.FormName.value=="StudentReg2013rx" || document.FormSelect.FormName.value=="Toddler Update Form v3rx")
{
document.FormSelect.action = "GenerateXDP.php";
}
When I remove it, both alerts are displayed. So the answer to my question is that changing the action does not submit the form; it was some other error in my code that made it appear as if that was the case.

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