I am a real noob when it comes to javascript/ajax, so any help will be very appreciated.
In reference to this question:
Updating a MySql database using PHP via an onClick javascript function
But mainly concerned with the answer left by Phill Sacre. I am wondering if someone could elaborate on how we are(if we can?) passing values/data through his example, using jquery.
The code example left by him is as follows:
function updateScore(answer, correct) {
if (answer == correct) {
$.post('updatescore.php');
}
}
...
<a onclick="updateScore(this, correct)" ...> </a>
Say for example, we are wanting to pass any number of values to the database with php, could someone give me a snippet example of what is required in the javascript function? Or elaborate on what is posted above please?
Thanks again all.
The simplest example I can think of is this. Make your AJAX call in your if block like this:
$.get('updatescore.php', {'score': '222'}, function(d) {
alert('Hello from PHP: ' + d);
});
On your "updatescore.php" script, just do that: update the score. And return a plain text stating wether the update operation was successful or not.
Good luck.
P.S.: You could also use POST instead of GET.
What you would do is on the php server side have a page lets say its update.php. This page will be visited by your javascript in an Ajax request, take the request and put it in a database.
The php might look something like this:
<?php
mysql_connect(...)
mysql_query("INSERT INTO table
(score) VALUES('$_GET["score"]') ")
Your javascript would simply preform an ajax request on update.php and send it the variables as get value "score".
Phil is not passing any values to the script. He's simply sending a request to the script which most likely contains logic to 'update' the score. A savvy person taking his test though could simply look at the HTML source and see the answer by checking to see what the anchor is doing.
To further nitpick about his solution, a set of radio buttons should be used, and within the form, a button or some sort of clickable element should be used to send the values to the server via an ajax request, and the values sent to the server can be analyzed and the status of the answer sent back to the page.
Since you're using jQuery, the code can be made unobtrusive as seen in the following example:
$('#submit_answer').click(function() {
var answer = 'blah' // With blah being the value of the radio button
$.get('updatescore.php',
{'value': answer},
function(d) {
alert('Your answer is: ' + d') // Where d is the string 'incorrect' or 'correct'
}
});
Enjoy.
Related
I am currently trying to implement the pre-built inline editor located here: https://github.com/wbotelhos/inplace
Unfortunately, the support documentation leaves a lot to desire and I have very little experience with Javascript, jQuery, or Ajax.
I have been able to successfully implement the HTML edits:
<td><div class="inplace" data-field-name="name" data-field-value="{{people['name']}}" data-url="/update/{{id}}">{{ people['name'] }}</a></td>
The Js:
<script type="text/javascript">
$('.inplace').inplace();
</script>
and have successfully grabbed, and printed the info sent from the Javascript.
#app.route('/update/<id>', methods=["POST", "PATCH"])
#login_required
def update(id):
new_data = request.get_data(as_text=True)
print(new_data)
return "200"
The issue I am facing, is that the Js returns an Undefined value which is what the HTML updates to.
Ignore the return "200" - I have tired several different methods. Success = True, json values, etc and nothing seems to work.
I am sure I am missing something simple.
It looks like you need to print json with the field name that matches your field_name attribute which is name.
So you will need to print something like this. I don't use python, so you will need to follow actual python syntax. Where the word name is correct, but you will need to add the value that you want shown
print('{"name":"NEW FIELD VALUE"}')
I have simplified my Code to breakdown the Problem and to have a simple Example with a Timestamp for whats actually going wrong.
So please not be suprised why i do a AJAX call, this is for the real functionality of the Servlet.
Its a Servlet and the follwing code is part of a JSP page, im Working on JAVA 1.7 and a Tomcat 7. I run it in Firefox and Chrome.
My goal is to retrieve a value from a Java method and write it on the servlet page into the DIV "ContentCharts".
The Problem is that Javascript does not update the vaule of "zeit" and always writes the same Timestamp into the DIV-Container and on the Console
$(document).ready(function()
{
function ausgabe()
{
<%
GregorianCalendar now = new GregorianCalendar();
DateFormat df = DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.LONG);
String JZeit = df.format(now.getTime());
System.out.println("FKT ausgabe zeit:"+ JZeit);
%>
var zeit='<%=JZeit %>';
console.info('Zeit:', zeit);
document.getElementById('ContentCharts').innerHTML = zeit;
}
$("#subtab2").click(function()
{
$.ajax
(
{
url:'overview',
data:{dbname:this.className},
type:'get',
cache:false,
success:function(){ausgabe();},
error:function(){alert('error');}
}
);
}
}
To test this I write the value of the JAVA varible "Jzeit" into the Serverlogs and get this (Click to see the Picture) results when I click the buttons three times. As you can see in the Picture here I get the right Timestamps.
Now I have also post the Value of the JS varialbe "zeit" into the Firebug Console. And now i get the Wrong time Stamps (Click to see the Picture)
The Content in the DIV is refreshing but here is the same Problem like in the Console, its always the same Timestamp.
These are my thoughts and Questions:
Why has the JS variable the wrong value when its right in JAVA?
Is there any option to say JS that it has to update the variable?
Could it be that JS saves the answers of the JAVA code and does not run it anymore, but runs the upper JAVA Code Snippet because there is no direct connection betwen JS and JAVA, like a value allocation?
How can i fix my Problem?
If you need more Informations to help me please ask for it.
You're a bit confused about the ajax pattern.
Note that anything you write in <%= jsp tags %> will be rendered on the server, then sent to the client where it will never change. Therefore your ausgabe function will always return the same result when it is called. Subsequent calls to the function will not make repeated server requests, which is the behavior you're observing.
To fix this, the success function in your ajax call should take an argument which will be instantiated with the response from the server. The java code you've written in the jsp tags in the ausgabe function should be moved to the server and any variables you need should be returned from the overview endpoint. Then, the ausgabe function should be refactored to take an argument containing the server-calculated values, and update your page as desired.
Here is some reading on ajax requests:
https://developer.mozilla.org/en-US/docs/AJAX/Getting_Started
http://api.jquery.com/jquery.ajax/
Okay, so I have this function in PHP that gets an attribute and returns an array. Something like this:
function getProvinces($countryID){
return arrayWithProvinces($countryID);}
Everytime the parent select changes, the function getProvinces() should be executed with the new ID and the arrayWithProvince should be included as options in the child select.
I'm using jquery to handle the events, as I found somewhere. I need to do something like this.
$("#selectCountry").change(function() {
var parent = $(this).val(); //get option value from parent
var prov = <?php echo json_encode($pagina->getProvinces( <PARENT> )); ?>;
list(prov);
My problem is that I don't know how to tell the getProvinces($countryID) php function which is the new value of the parent.
Thanks in advance.
You should use javascript for that in order to refresh part of your page with dynamic content.Below is an example using jquery's ajax function.When the select with id #parent_select changes you call your php script and you append the returned data (the html of the child select in the example) in a div you want.
Javascript part would be something like this:
$("#parent_select").change(function() {
$.ajax({
url: "your_script.php?cid="+$(this).val(),
success: function(html){
$("#child_select_container").append(html);
}
});
});
And your_script.php code would look something like :
<?php
function getProvinces($countryID){
return arrayWithProvinces($countryID);}
$countryID=(int)$_GET['cid'];
$provinces=getProvinces($countryID);
echo '<select id="child_select">';
foreach($provinces as $key=>$province){
echo '<option id="'.$key.'">'.$province.'</option>';
}
echo '</select>;
I havent tested the example.It is just a basic how to example.You should be able to work your way from here.But if you have any problems let me know.
As far as I know, you cannot execute the function without reloading entire page (I mean php should recompile it and pass it to the client).
You should use only JavaScript for that purpose. Store you arraylist in JS code, and validate it once upon form submission (just to be sure).
You need to make an Ajax request to the server.
Look at it this way: Your Javascript/jQuery is running on the client side (web browser) and you PHP is running on your web server.
So to communicate between the browser(jQuery) and the server(PHP) you need to make a Ajax request.
jQuery has a ajax function you could use, your best bet is to do some research on the subject as Ajax is something you will use all the time and understanding how it works is crucial.
so i've been looking at how to record and send client-side data to a php server.
i'm not sure of the correct terminologies, but i think that using an ajax call to send a post to the php server is the most elegant way to solve this problem.
so i decided to implement this data exchange:
$("#"+activityInfo.ID).click(function(){
window.open(activityInfo.URL+"userId="+$("#userid").val()+"&activityId="+activityID+"&classId="+classID);
classid = classID;
activityid = activityID;
$("body").append("class: " + classid);
$("body").append("id: " + activityid);
$.post('http://chemcollective.org/chemvlab/php/updateProgress.php', { 'cid':classid , 'aid':activityid } );}); //i think this is the important line that sends the data
and the corresponding php file (updateProgress.php)
$class_id = $_POST['cid']; //receives the data
$activity_id = $_POST['aid'];
i'm not sure why this is the case, but class_id and activity_id variables always return an empty value.
i understand somewhat that the client-browser is on a page that is preloaded by information from a php server. but there were posts that said this is a possible way to communicate back to the php server with information from the client. i'm not really sure what is going on b/c at this point i don't really know what questions to ask.
one of the example explanations that i had been following:
Ajax passing data to php script
thanks for the help.
i've also played around with start_session() and storing/loading session variables as a way to transfer data information. this works but only for php <-> php communication. it does not for saving javascript variables, so i couldn't really use $_SESSION = ..... in my javascript code.
you need to get the cid and aid outside of the single-qouts while using $.post! try this:
$.post('http://chemcollective.org/chemvlab/php/updateProgress.php', { cid:classid , aid:activityid } );
Need a little help in here. I just want to delete a row from database using javascript. But facing some problems.
Here is my view:
<?php echo anchor("#","Delete",array('class'=>'selectedpagination', 'onclick'=>'confirmDelete("admin/editpage/","'.$file->page_id.'");'))?>
And Javascript is here
function confirmDelete(controller,id)
{
if(confirm("Are you sure you want to delete this record"))
{
<!--location.href="main.php?page="+page+"&tblname="+tblname+"&fldname="+fldname+"&id="+id+"&action=delete";-->
window.redirect("http://localhost/sama/index.php/admin/"+controller+"/"+id);
}
How to make it work?? Its not working.
Please anyone or someone, desperately needing help. Thanks in advance.
You might want to consider using jQuery's shorthand AJAX function $.post() to post data to the page you need like so:
function confirmDelete(controller, id){
if(confirm("Are you sure you want to delete this record")){
var data = "page="+page+"&tblname="+tblname+
"&fldname="+fldname+"&id="+id+"&action=delete";
$.post(controller, data)
.done(function(data) {
// redirect or further logic here
});
}
}
Server-side you receive each of your posted variables like:
$action = $this->input->post('action');
Besides the above solution, you may want to rethink your approach to this. You are sending data to a controller through javascript and then you redirect the browser to another page using javascript throughout the process. It may have been easier to just call the controller and pass the variables you need by the session cookie or through the url and when everything is done server-side, use codeigniter's redirect() helper function to redirect the browser to where you want. The use of javascript and AJAX here would be fine if you wanted to build an asynchronous application... but... ajax call and redirection rather blow the purpose of asynchronous calls. Hope I helped a bit.