how to send a single element from browser to server without reload - javascript

How can I send just one element from browser to server fast and without reloading browser page?
Is there an AJAX way to do this, that is a NON-FILE method? The opposite of ".load"?
.load works great sending a single element from server to browser without page reload.
How to do the opposite direction?
Browser is JavaScript.
Server is vxworks with windmarks.
PRESENT METHOD THAT WORKS BUT RELOADS PAGE:
Presently, the browser element is and I use submit to send it to the server, but this takes too long and reloads the browser page.
The element's innerHTML contains data formatted as a vxworks WINDMARK.
(When the vxworks server receives this submission, it reads the windmark and copies it to a 'C' string for backend software to process.)

If you're using jQuery and PHP then something like this should work:
JS:
$.ajax('doServerSuff.php?action1=saveLog', function() {
// do stuff after server received the data
});
PHP (doServerStuff.php):
<?php
if ($_GET['action1'] == 'saveLog') {
//do stuff
}
?>

You can get and send data using jQuery. using something like this:
$.post('urlfromserver',browserdata,function(datafromserver){
//do stuff
})
if you let me put a little bit more, it's a good idea to use JSON to send/receive data to/from server. Having that in mind, you can do something like:
$.post('urlfromserver',{browserdata: JSON.stringify(browserdata)},function(datafromserver){
javascriptObject = jQuery.parseJSON(datafromserver)
//do stuff
})
And in your PHP code, it would be as simple as using json_encode to send data to javascript and json_decode to receive data from javascript
UPDATE
Obtaining the data in the server should be as simple as requesting the object via post or get depending on your send method, and parsing the JSON.
In PHP, this is an example of obtaining data using the above code:
$dataFromBrowser = json_decode($_POST['browserdata'])

Use $.post in jQuery to send the data.

The load intruction can also be used to transmit data to the server:
$().load("url", {limit: 25}, function(){
//transmission finished
});
In this example the parameter limit with the value 25 wil be transmitted to the server.
Taken from:http://api.jquery.com/load/

You can simply do with the ajax call like this
$.ajax({
type: "POST",
url: "yourpage.php?id=someValue",
success:function(data){
//do some stuff here
});

I got it working. Here is the corrected JavaScript, from the above answer.
Here is how to change a single element at the server.
This is also an example of how to write to a vxworks windmark string at a vxworks web server, without reloading the page.
NOTE: no URL is specified, so that the same page is used.
$.ajax({
type: "POST",
url: "?general_page_to_MM_data_1_windmark=CCCCCCCCCCCCCC",
success:function(data_from_server){
}});

Related

How to use JS to display images from database

So I made a website that displays FPS information stored in a mysql database. For each second of gameplay I have a pair of number(fps)-image(screenshot).
I display the numbers in a line chart made with JavaScript. The behaviour desired is when I click on a bullet in the chart, the screenshot for that particular second is displayed in a div on the page.
I have to mention that the screenshots are stored in the database and they are very low in size. I display then using PHP like this:
$query = "SELECT `image` FROM `logs` WHERE `session_id`=".$_GET['session']." AND `second`=".$second;
$sth = $mysqli->query($query);
$result=mysqli_fetch_array($sth);
if (!empty($result))
echo ' <img id="screen" src="data:image/jpg;base64,'.base64_encode($result['image']).'"/>';
The method I'm using now is when I click on a bullet in the chart (action recorded in JS), I send it as a GET parameter and read it with PHP afterwards, like this:
window.location.href = url + "?second=" + second;
This method obviously will refresh my page. The problem is, the chart I made also has a zoom/scroll option and that resets whenever the page is refreshed, making the experience very bad for the user.
Is there any method to display the screenshots without refreshing the page, for this particular case (where I have to query the database for each click/picture)? Maybe there is a better way of approaching this problem?
Thanks.
I think you've got 2 solutions which are Ajax or Websocket depending your needs.
AJAX
Ajax permit to asynchronously, only when you need, call the server and get datas from an URL which could be a webservice or PHP page... Perhaps, it's the better solution in your case.
To make it easy, you can use JQuery library by donwloading the script and insert it in your HTML :
<script src="jquery-3.0.0.min.js"></script>
To call the server, using JQuery :
$.ajax({
url: url + "/yourphppage.php",
data: "parameter=" + yourOptionelParameter,
async: false,
success: function(data) {
refreshYourChart(data);
},
error: function() {
alert("Your error");
},
contentType: 'charset=utf-8'
});
Or if your prefer pure javascript.
Now, you just have to work on the presentation of your data, on the server side. It could be what you want HTML, TXT, JSON, XML...
Websocket
Websocket is like a permanent tunnel opened between your server and the client. Each side can ask or send datas in real time.
It seems to be a library server side :
http://socketo.me/
And client side, it's very easy :
Nice documentation on mozilla website
Hope it helps. Good luck.
To change a picture source, as I see the easiest way is using an ajax call, so you can send any kind of parameters to your server, and in return your will get your new picture source.
$.get('urlToYourServer.com?parameter=1', function(data){
$('#img').attr('src', data.imgSrc);
})

How to use `GET` parameters in a HTML document?

I have a HTML document and I want to send a parameter.
Let's name the document Categoty, and all it do it sends a request to the server (via Ajax) to get something on this categoty.
Suppose I'm using PHP, I would simply send the parameter:
localhost/Categoty.php?cat=somecat,
and read it in the PHP document: $_GET['cat'].
My question is if there's something similar in HTML (or Javascript)?
I though about hashtag (.i.e. categoty.html#somecat) , but I'm using jQuery mobile in my Android Hybrid application so it makes some issues.
Thanks in advance.
use the jQuery URL Parser in this link and then try:
jQuery.url().param('cat');
you can also access all other info we usually need in terms of dealing with GET parameters, like:
jQuery.url().attr('protocol');
returns the URL protocol like: http or https
jQuery.url().attr('host')
returns the host like stackoverflow.com
you can also get the segments of your URL like this:
jQuery.url().segment(1);//for instance in this very page's url it returns "posts"
at the end:
jQuery.url().param('cat') in javascript does the same as $_GET['cat'] does in PHP
jQuery ajax can do it , use $.ajax();
$.ajax({
type: 'GET',
url: 'http://localhost/Categoty.php?cat=somecat',
success: function(responseTxt,statusTxt,xhr){
}
});

JQuery Send data to page using jQuery Post and data()

I'm having a bit of difficulty conceptualising this: I have some data stored to a button:
var input2 = '<button id="viewmap1" class="viewmap">Find on Map</button>';
//MAKE DATA
$(input2).data('longlat', coords);
Now I want to send that data to another page. I understand I am to use jQuery post, eg:
$.post("test.html", { func: "getNameAndTime" },
function(data){
alert("Hello");
}, "json");
But im not entirely sure how to go about it. Can any one point me in the right direction? Thanks
Sending data to a different page isn't as simple as it sounds. If it were simple, crackers could manipulate all the other pages that you currently have open in browser tabs.
When you call $.post(), that just sends data to the server, not to another page. The URL is a way to tell the server how to process the data but it doesn't magically connect you to the browser tab/window which has test.html open.
The usual solution is to use a single page which contains the button and the elements to display the results (a.k.a "view"). You send the POST request and then update the view in the callback function.
$(input2).on('click', function(){
// do your post stuffs
});
then need to trigger the button click
$(input2).click();

Get data using POST and AJAX

I'm trying to send some data in my server asynchronously using AJAX.
I need to send the data using the POST method because the data sent are quite
many characters and by using GET the created URL will be too big. Well that's not a problem, but for aesthetically reasons I would rather have small URLs. In order to do so I used the solution (question) explained here.
My Javascript code sending the data is:
var code = "code=" + document.getElementById("code_area").value;
xmlhttp.open("POST", "run_code.php", true);
xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlhttp.send(code);
The above code is executed when I click a button, but then the URL changes to this: localhost/code.php?code=datadatadatadatadatadatadatadatadatadatadatadatadatadata which seems is no different of using GET instead (my URL has become quite big). I used POST, not GET but still data seems to get transmitted by the URL. Any ideas why is this happening?
You could do that much more easily using jQuery.
$.post("run_code.php", { code: $("#code_area").val() });
Links:
How to add jQuery support to your code.
jQuery documentation.
$.post() documentation.
Way easier with jquery...
$.post( 'yoururlhere.com/phppage',
{code:$("#code_area").val()},
function(responseData){
// responseData is the echo'd data set from your php page
}, 'json'
);
the data within { } are the post K-V pairs
responseData is the dataset echo'd back from php
The problem after all was that I was using a submit input field in my HTML page like this:
<input type="submit" />
which when used changed (refreshed) the URL.
By using:
<input type="button" />
the problem has been fixed.

.load() with data

I want to load data into a checkout page using .load() to load the pages in a modal window. The data that needs to be loaded is a shipping price value, that needs to be usable on the loaded page.
JS
function totalCalc() {
var shipping = ($('#shippingform input[name="shipping"]').val());
$('#cartdialog').load("/ash/shop/checkout.php",[$('#shippingform input[name="shipping"]')]);
alert(shipping);
}
CHECKOUT.PHP
$myTotal = ($subtotal + $_POST['shipping']);
I need the value which is shown through the "alert(shipping);" to be a usable value on checkout.php. You'll see I try to $_POST[] it in a php variable, but it wont work. I must be sending the data wrong...
Per the jQuery API, data sent as a query-string format string through .load() is treated as GET. Data sent as a JSON object is treated as POST. Basically, send it like this:
.load("/ash/show/checkout.php", {shipping: shipping});
As it seems you're using jQuery: http://api.jquery.com/jQuery.post/
or if you want proper control over it, use the ajax method: http://api.jquery.com/jQuery.ajax/
Alternatively, you could add the shipping cost to the URL and use $_GET

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