I'm fairly new to jQuery and OOP in PHP,
but what I have is a PHP Object that has an array
$array[0] = "a"
$array[1] = "b"
$array[2] = "c"
$array[3] = "d"
and a select box in my HTML
<select class="box">
<option value="1">First Letter</option>
<option value="2">Second Letter</option>
<option value="3">Third Letter</option>
<option value="4">Fourth Letter</option>
</select>
<div></div>
How do I dynamically change whatever is in the div tags as someone changes the value of the select box using jQuery?
Is there a way to do something like
$('.box').change(){ var value = $object->array[index-1]}?
Assuming I had already have the value for index.
EDIT
I know I'll have to use Ajax, but I'm not sure how to call a method in an instance of an object already made.
You can't access PHP through javascript. There are several possible solutions:
Load all of the possible data combinations at once onto the page stored somewhere in the DOM. As the user cycles through the options, change them appropriately.
Load only the initial elements onto the page without javascript, then use Ajax to load all other possible combinations.
Load each combination with ajax on the fly.
You can either have javascript make an Ajax request to the same page and filter the request, or you can create a proxy that will serve only the requests you need when hit with ajax.
Remember that you are trying to combine PHP with Javascript.
Your code will primarily be written in javascript, but you'll
only inject bits of PHP code into the javascript code.
As in this instance, use the standard jquery onchange event method 'change()'
for the selectbox, set the javascript variable value to $object->array[0]
from PHP.
$('select').change(function() {
var value = <?php echo $object->array[$index] ?>
$('div').html(value)
});
You can use the php function json_encode to turn your php data into a javascript object. e.g
<script type="text/javascript">
var mydata = <?= json_encode($myarray) ?>;
console.log(mydata);
</script>
Related
Is it possible in PHP to find and replace a PHP variable with a user defined value from a drop down box on a different PHP page.
Example:
PHP Page 1
$test = '1234';
PHP Page 2
Drop Down Values: (Find and replace $test variable with Drop Down selection)
1
2
3
4
Im have not found much information about this.
The purpose is to pass hexadecimal colours based on user choice.
PHP Variables are server-side variables. You can not change server side variables from client side directly.
Common approaches are: (Although both do same in background)
Using GET to send your data
Using AJAX to dynamically send, fetch and change DOM (Maybe preferred in our case)
On selecting the item on the Drop Down menu, you need to call a method which sends a data to your PHP page and you can change variables.
Your PHP page should handle a GET request change the variable to $test
$test = $_GET["sent_variable"]
While on AJAX, you need to something like:
$.ajax({
url: "your-php-page.php",
type: "POST",
data: { sent_variable: selectedVar}
}).done(function() {
//Something here after doing
});
Read more about AJAX here.
Note: You have to trigger AJAX on selecting drop-down menu. Read about that here.
Assuming the dropdown box is part of a form, you can use the 'post' method.
e.g.
<!--HTML-->
<form method="post" action="myScript.PHP">
<select name="myOption">
<option value="1">1</option>
<option value="2">2</option>
</select>
<input type="submit" value="GO">
</form>
//myScript.php file
<?PHP
$test = $_POST['myOption'];
echo $test;
?>
I actually have a page on my own site that uses similar functionality for passing hex colours if you want to have a look at the HTML source code http://www.wxls.co.uk/formatmyvba.html
how can i change/assign a value to php variable depending on a javascript variable?
here is my code.
<select id="reOutcome" name="reOutcome" onchange="OnChange(this.form.reOutcome);">
<option value="1">Value 1</option>
<option value="2">Value 2</option>
<option value="3">Value 3</option>
</select>
<script type="text/javascript">
function OnChange(dropdown)
{
var myindex = dropdown.selectedIndex
var SelValue = dropdown.options[myindex].value
if(SelValue==2){
<?php
$sCOMPFields .= "|"."SreComments";
$sCOMPFields .= "|"."rePrID";
?>
}
return true;
}
</script>
The onchange function is working fine. I just don't know how to change the php variable. I searched online a lot. All im getting is how to assign php variable to javascript. That is not what im looking for.
Thanks for your help.
The execution you want won`t occur, because the flow of the php scope and the javascript scope occurs on different moments. It is something like this:
So, you can`t execute php while the javascript is being executed on the computer of the user through the browser, but you can execute php on your server to generate the javascript you need to be executed on the user computer.
Actually, your question seems to be closer to a "what is the best way to do (something)"
PHP variables are set at run time. You can't do it directly within the javascript. Off the top of my head the best way I can think of to do it would be to set the php variables as session variables. Then use your javascript to call a php file via ajax/jquery that can update the session variables.
that's exactly we use ajax.
make the page loads in default preferences, then update it using ajax
I populate a drop down box from an array that uses Javascript on the page load. But I am pulling data out of a database how would I change which one was selected? I would prefer not to have to use PHP to create the drop down boxes, as I have other non php things that use the javascript as well. What Can I do to get my Drop DownList populated from PHP?
You can see that it just calls the SelectdeptDropdown function.
<label for="collegedropdown">Collge</label>
<select name="collegedropdown" id="collegedropdown" onChange="SelectDeptDropdown();">
<option selected="selected">Choose a college</option>
</select>
<br />
<label for="deptdropdown">Department</label>
<select name="deptdropdown" id="deptdropdown">
<option selected="selected">Choose a department</option>
</select>
Javascript Code:
removeAllOptions(document.profilecreate.deptdropdown);
addOption(document.profilecreate.deptdropdown, "", "Choose One", "");
if(document.profilecreate.collegedropdown.value == 'MY CHOICE #1'){
//all options here
}
//repeat for other cases here
NOTE: removeAllOptions calls another function that simply clears the dropdown list. addOption calls a function that creates the option element.
basically you need to use an XHR Request. The XHR request will hit another end point of your php server which will return data for you to populate the dropwdown field and then you can use some smart javascript to insert into the dom.
Tne end point should ideally return a json data which will only be the dropdown values and you generate the markup on the client side this is ont compulsory but recommended.. read more abt XHR and json here.
Finally I would suggest you to use a library like jquery that gives you simple api for XHR requests and DOM manipulation using which you can get your job done quickly.
I have a page with php and javascript. In the php section i need to call a function with an argument $arg, Now $arg is the problem, $arg is actually value of a dropdown option in the same page . Here is what i am trying to accomplish.
<?php include("aclass.php")?>
<script language="javascript">
function getoption(val){
}
</script>
<html>
<select name="sel" onchange="getoption();">
<option value="1">One</option>
<option value="2">Two</option>
</html>
<?php
$object=new a;
$object->calculate($arg);
?>
// Here the issue is $arg should be the value i select in dropdown, $arg should be 1 if i select One and should be 2 if i select Two in dropdown.
" Is there a possibility to pass the javascript value 'val' to php variable $arg "
The thing you want to do is not possible without a form submission or without a contact to the server. PHP is a server side language whereas javascript is client side. So obviously you cannot do a server function in the client side.
So, either make this as a form and submit the form on change of the value in select or if you dont want reload of the page, try using ajax
You can use PHP variables in Javascript but the opposite can't be done. PHP runs server-side. Javascript is client-side. The only way to send something from Javascript to PHP is using AJAX. You might want to search in that direction.
I want to display the photos according to the album selected. But, I don't want to post the page, I want to just change the div.
This is my script:
<script type="text/javascript">
function replaceContent(divName, contentS) {
document.getElementById(divName).innerHTML = <?php echo get_pictures_from_album($fb, $albums, contentS); ?>;
}
</script>
And this is the select tag that invokes it:
<select name="album" size= "1" style="width:210;" onchange="replaceContent('photos', this.options[this.selectedIndex].value);">
<?php get_albums_select_list($albums); ?>
</select>
<div id = "photos">
<?php echo get_profile_pictures($fb, $albums); ?>
</div>
I understand from a reading that I have done that the problem might be connected to javascript Vs php variable types.
Please advise.
Looks like you are looking for an AJax call to an PHP script that retrives the data for the appropriate album selected and THEN update the div with the callback function.
Ajax + PHP basics
You are mixing Clientside and Serverside Code here. The function replaceContent is called after the page (and the php code) was loaded. You would need an Ajax Call for that if you need more information about that:
Ajax Tutorials on Google
What you are doing is not possible because PHP code runs before (on the server because PHP is server-side language) javascript code.
You will have to resort ot AJAX for that.