I have a page that loads a random MP3 file on each refresh. The user has to guess a name based on the sound via text form input. I want to check their input against the stored string and refresh the page if it's correct. Otherwise, I wan't to give them an incorrect alert and stay on the same page so they can guess again:
<div class="ui-widget" align="center">
<form method="post" action="" class="answer_box" onsubmit="return submit();">
<p>Which hero is it? <input id="tags" name="guess" /></p>
<script>
var key = <?php echo json_encode($rand_key) ?>;
var info = document.getElementById("guess").value;
function submit() {
if (key==info){
alert('Correct!');
return true;
}
else {
alert('Incorrect!');
returnToPreviousPage();
return false;
}
}
</script>
</form>
</div>
Right now, it submits the information to a new page regardless of the input. The javascript alerts are also not showing (I suspect they do show, but the page then refreshes and they disappear). The key variable is the key from the randomly taken value of a PHP array, and info should be the text the user inputs.
Problems found:
you cant use submit as a function name a this is an HtmlForm object
document.getElementById("guess").value; is looking for an element with ID of "guess" and that does not exist.
I would rewrite your script like this:
<script>
var key = <?php echo json_encode($rand_key) ?>;
function my_submit(curr) {
var info = curr.guess.value;
if (key == info) {
alert('Correct!');
return true;
}
else {
alert('Incorrect!');
returnToPreviousPage();
return false;
}
}
</script>
<form onsubmit="return my_submit(this);">
<p>Which hero is it? <input id="tags" name="guess"/></p>
</form>
You have a problem here:
<input id="tags" name="guess" />
Your id is tags, not guess.
You should use document.getElementById("tags").value.
You are trying to retrieve the value of an element with id of "guess." Change this to "tags."
var info = document.getElementById("tags").value;
Also, as #CodeGodie mentioned, you need to change your function name to something other than submit.
Related
I have a textfield:
Voornaam: <h3 class="title1">Kevin</h3>
<input type="text" id="myTextField1" />
<input type="submit" id="byBtn" value="Change" onclick="change1()"/><br/>
I can set a value of this using this function:
function change1(){
var myNewTitle = document.getElementById('myTextField1').value;
if( myNewTitle.length==0 ){
alert('Write Some real Text please.');
return;
}
var titles = document.getElementsByClassName('title1');
Array.prototype.forEach.call(titles,title => {
title.innerHTML = myNewTitle;
});
}
Now in my other page, I want to use the value. I know I can for example pass a value from one page to another like this:
<a href='convert.php?var=data'>converteren.</a>
And then for example show it by doing this in the other page:
echo $_GET['var'];
But I cant really seem to figure out how to use the value which I've set using my textfield.
So my goal for now is to display the value I've set using my textfield in the other page using the method I just described.
Basically all I want to happen is for my textfield to change the value inside here aswell:
<a href='convert.php?var=data'>converteren.</a>
So where data is the value, I want it to become what I've put in the textfield.
Could anybody provide me with an example?
I've altered a bit your javascript code to make the link as you want.
To explain the answer, i've added document.getElementById("myLink").href="convert.php?var=" + myNewTitle ; which updates your a href while your function runs and is not empty.
function change1(){
var myNewTitle = document.getElementById('myTextField1').value;
if( myNewTitle.length==0 ){
alert('Write Some real Text please.');
return;
}
document.getElementById("myLink").href="convert.php?var=" + myNewTitle ;
var titles = document.getElementsByClassName('title1');
Array.prototype.forEach.call(titles,title => {
title.innerHTML = myNewTitle;
});
}
<a id="myLink" href='#'>converteren.</a>
Wrap your inputs inside a form element.
In the action attribute, specify the destination url.
In the method attribute, choose between GET and POST.
For example:
<form method="GET" action="convert.php">
<input type="text" id="myTextField1" />
<input type="submit" id="byBtn" value="Change" onclick="change1()"/>
</form>
Clicking the submit button will call "convert.php?myTextField1={value}".
I have a single form input on my homepage userinput. The homepage also contains a JavaScript function that uses that userinput value to calculate a result.
<form action="/run.php" method="POST" target="_blank">
<input type="hidden" id="idg" value="<?php echo $rand ?>"> // gets random url, can be ignored
<input type="text" name="userinput" id="userinput">
<button type="submit" onclick="calcResult();">Go!</button>
</form>
<script>
function calcResult() {
var userinput = document.getElementById('userinput').value;
var result = userinput + 10; // want to POST result in a hidden input field w/ form
</script>
I'm trying to find a way in which a user can enter their input, submit the form, the JavaScript takes that userinput and calculates a result, then that result is POST'ed along with the userinput in the form.
The problem I can forsee with this method is that:
The JavaScript function needs the userinput before it can calculate the result. However, the only way to get the userinput is to submit the form, which means the form data will be POSTed before the JavaScript result is returned.
My attempted solution(s):
I've been attempting to use AJAX (Unable to access AJAX data [PHP]) and have been consistently running into issues with that.
I was wondering whether it's possible to use a button (type="button"), instead of a submit (type="submit") for the form. Then just use that button to call the JS function, then (somehow) submit the form (with the JS function result) after the JS function has completed? (either with plain JS or jQuery).
there are multiple approaches to do this,
i'm gonna use jquery here instead of pure javascript to simplify it
[without submission] you may check the event change
$('#userinput').change(function (e) {
// make some calculation
// then update the input value
});
[with form submission] you will disable the submission using the object preventDefault inside the submit event
$('#userinput').submit(function (e) {
e.preventDefault();
// make some calculation
// then update the input value
// your ajax goes here OR resubmission of your form
// to resubmit the form
$(this).submit();
});
What you will find useful in this scenario is event.preventDefault();
function calcResult(e) {
// Prevent the default action of the form
e.preventDefault();
var userinput = document.getElementById('userinput').value;
var result = userinput + 10;
// Do whatever else you need to do
// Submit the form with javascript
document.getElementById("myForm").submit();
}
I believe this is what you are looking for. A way of having the information computed over PHP, without a page request. This uses a form and then serializes the data, then transmits it to PHP and displays the result from run.php.
Note:
I did change your id to a name in the HTML so the code would serialize properly. I can change this per request.
index.php
$rand = rand(10,100);
?>
<form action="javascript:void(0);" id="targetForm">
<input type="hidden" name="idg" value="<?php echo $rand ?>">
<input type="text" value="12" name="userinput" id="userinput">
<button onclick="ready()">Go!</button>
</form>
<div id="result"></div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.0/jquery.min.js"></script>
<script>
function ready() {
$.post('run.php', $('#targetForm').serialize(), function (data) {
$("#result").html(data);
})
}
</script>
run.php
<?php
echo floatval($_POST['userinput']) * floatval($_POST['idg']);
?>
Nowhere in your question is there any indicator that your task requires AJAX. You're just trying to change an input value right when you submit. AJAX is not needed for that.
First, attach an onsubmit event handler to your form instead of using an onclick attribute on your button. Notice, we are not stopping the form from submitting with return false as we still want the form to submit.
For convenience, let's add an ID to your form and let's add a hidden input field to store the calculated value.
(Side-remark: you don't need to use document.getElementById(ID) if the ID is a string with no dashes i.e. document.getElementById('userinput') can be shortened to just userinput )
<form action="/run.php" method="POST" target="_blank" id="theform">
<input type="hidden" id="idg" value="<?php echo $rand ?>">
<input type="text" name="userinput" id="userinput">
<input type="hidden" name="hiddeninput" id="hiddeninput">
<button type="submit">Go!</button>
</form>
<script>
// this will be called right when you submit
theform.onsubmit = function calcResult() {
// it should update the value of your hidden field before moving to the next page
hiddeninput.value = parseInt(userinput.value, 10) + 10;
return true;
}
</script>
One way is by onSubmit
<form action="/run.php" method="POST" onSubmit="return calcResult()">
<input type="hidden" id="idg" value="<?php echo $rand ?>"> // gets random url, can be ignored
<input type="text" name="userinput" id="userinput">
<button type="submit" onclick="calcResult();">Go! </button>
</form>
And when you return true then only form will submit.
<script>
function calcResult() {
var userinput = document.getElementById('userinput').value;
var result = userinput + 10; // want to POST result in a hidden input field w/ form
return true;
}
</script>
In PHP, if the text input "cmtx_comment" is empty, on form submit I show a javascript alert. After I press OK in the alert, the values entered by the user in all fields in the form are gone. How can I keep the user entered values, without adding code to the value of the input elements (something like <input type="text" name="something" value="<?php echo $_GET['something'];?>"> ?
if (empty($cmtx_comment)) { //if comment value is empty
echo <<<EOD
<script>
alert('Please enter a comment!');
</script>
EOD;
return false;
} else { //if comment entered
do stuff
Have you tried localStorage and form validation?
HTML:
<form method="post" action="" onSubmit="return saveComment();">
<input type="text" name="cmtx_comment" id="cmtx_comment" value="" />
<input type="submit" value="Save" />
</form>
JavaScript:
document.getElementById("cmtx_comment").value = localStorage.getItem("comment");
function saveComment() {
var comment = document.getElementById("cmtx_comment").value;
if (comment == "") {
alert("Please enter a comment in first!");
return false;
}
localStorage.setItem("comment", comment);
alert("Your comment has been saved!");
location.reload();
return false;
//return true;
}
Example
On first page load, you are presented with:
If you don't enter a comment, you get the alert:
If you do enter a comment, you get a different alert:
The page will then refresh (or post, simply un-comment the return true, and comment the location.reload), and you will still see the contents you posted the first time.
Say I got a HTML form like below and want to pass the values in the textfields to JS variables.
<form name="testform" action="" method="?"
<input type="text" name="testfield1"/>
<input type="text" name="testfield2"/>
</form>
I've only passed values to variables in PHP before. When doing it in javascript, do I need a method? And the main question, how is it done?
Here are a couple of examples:
Javascript:
document.getElementById('name_of_input_control_id').value;
jQuery:
$("#name_of_input_control_id").val();
Basically you are extracting the value of the input control out of the DOM using Javascript/jQuery.
the answers are all correct but you may face problems if you dont put your code into a document.ready function ... if your codeblock is above the html part you will not find any input field with the id, because in this moment it doesnt exist...
document.addEventListener('DOMContentLoaded', function() {
var input = document.getElementById('name_of_input_control_id').value;
}, false);
jQuery
jQuery(document).ready(function($){
var input = $("#name_of_input_control_id").val();
});
You don't really need a method or an action attribute if you're simply using the text fields in Javascript
Add a submit button and an onsubmit handler to the form like this,
<form name="testform" onsubmit="return processForm(this)">
<input type="text" name="testfield1"/>
<input type="text" name="testfield2"/>
<input type="submit"/>
</form>
Then in your Javascript you could have this processForm function
function processForm(form) {
var inputs = form.getElementsByTagName("input");
// parse text field values into an object
var textValues = {};
for(var x = 0; x < inputs.length; x++) {
if(inputs[x].type != "text") {
// ignore anything which is NOT a text field
continue;
}
textValues[inputs[x].name] = inputs[x].value;
}
// textValues['testfield1'] contains value of first input
// textValues['testfield2'] contains value of second input
return false; // this causes form to NOT 'refresh' the page
}
Try the following in your "submit":
var input = $("#testfield1").val();
<form method="post" action="sendmail.php" name="Email_form">
Message ID <input type="text" name="message_id" /><br/><br/>
Aggressive conduct <input type="radio" name="conduct" value="aggressive contact" /><br/><br/>
Offensive conduct <input type="radio" name="conduct" value="offensive conduct" /><br/><br/>
Rasical conduct <input type="radio" name="conduct" value="Rasical conduct" /><br/><br/>
Intimidating conduct <input type="radio" name="conduct" value="intimidating conduct" /><br/><br/>
<input type="submit" name="submit" value="Send Mail" onclick=validate() />
</form>
window.onload = init;
function init()
{
document.forms["Email_form"].onsubmit = function()
{
validate();
return false;
};
}
function validate()
{
var form = document.forms["Email_form"]; //Try avoiding space in form name.
if(form.elements["message_id"].value == "") { //No value in the "message_id"
box
{
alert("Enter Message Id");
//Alert is not a very good idea.
//You may want to add a span per element for the error message
//An div/span at the form level to populate the error message is also ok
//Populate this div or span with the error message
//document.getElementById("errorDivId").innerHTML = "No message id";
return false; //There is an error. Don't proceed with form submission.
}
}
}
</script>
Am i missing something or am i just being stupid?
edit***
sorry i should add! the problem is that i want the javascript to stop users going to 'sendmail.php' if they have not entered a message id and clicked a radio button... at the moment this does not do this and sends blank emails if nothing is inputted
You are using
validate();
return false;
...which means that the submit event handler always returns false, and always fails to submit. You need to use this instead:
return validate();
Also, where you use document.forms["Email form"] the space should be an underscore.
Here's a completely rewritten example that uses modern, standards-compliant, organised code, and works:
http://jsbin.com/eqozah/3
Note that a successful submission of the form will take you to 'sendmail.php', which doesn't actually exist on the jsbin.com server, and you'll get an error, but you know what I mean.
Here is an updated version that dumbs down the methods used so that it works with Internet Explorer, as well as includes radio button validation:
http://jsbin.com/eqozah/5
You forgot the underscore when identifying the form:
document.forms["Email_form"].onsubmit = ...
EDIT:
document.forms["Email_form"].onsubmit = function() {
return validate();
};
function validate() {
var form = document.forms["Email_form"];
if (form.elements["message_id"].value == "") {
alert("Enter Message Id");
return false;
}
var conduct = form.elements['conduct']; //Grab radio buttons
var conductValue; //Store the selected value
for (var i = 0; i<conduct.length; i++) { //Loop through the list and find selected value
if(conduct[i].checked) { conductValue = conduct[i].value } //Store it
}
if (conductValue == undefined) { //Check to make sure we have a value, otherwise fail and alert the user
alert("Enter Conduct");
return false;
}
return true;
}
return the value of validate. Validate should return true if your validation succeeds, and false otherwise. If the onsubmit function returns false, the page won't change.
EDIT: Added code to check the radio button. You should consider using a javascript framework to make your life easier. Also, you should remove the onclick attribute from your submit input button as validation should be handled in the submit even, not the button's click
Most obvious error, your form has name attribute 'Email_form', but in your Javascript you reference document.forms["Email form"]. The ironic thing is, you even have a comment in there not to use spaces in your form names :)