Understanding Ajax requests to update page content when SQL Query Response changes - javascript

I am writing a page update which works with PHP to read a SQL database the page echo's the contents in a div section 'track_data'. yet it doesn't do this update idk
I have JavaScript script which I dont really fully understand and hopeful someone could explain its principally the check response section I think is failing ? :
in my PHP page :
<script type="text/javascript">
function InitReload() {
new Ajax.PeriodicalUpdater('track_data', 'fetch_sql.php', {
method: 'get', frequency: 60, decay: 1});
}
</script>
Thanks for looking and hopefully someone undersstands this and can put a smile on my face for the second time today :)
Steps to fix
Thanks for the suggestions of syntax errors. I haven't really got very far with this here are the changes you suggested which I have changed but I still think there is something wrong with last function as it doesn't update div section.
Code in JS file
// Start Clock refresh
// uses new new Ajax.PeriodicalUpdater(
// in main fetch file to trigger the auto update of the page.
// Written by Denise Rose
var gUpdateDiv;
var gContentURL;
var gcheckInterval;
var gcheckURL = "";
var gCurrentCheck ="";
_fetchUpdater('track_data','/fetch_sql.php','/fetch_sql.php',8000);
function _fetchUpdater(updateDiv,contentURL,checkURL,checkInterval)
{
gUpdateDiv = updateDiv;
gContentURL = contentURL;
gcheckInterval = checkInterval;
gcheckURL = checkURL;
setTimeout('check();',gCheckInterval);
}
//Called by _fetchUpdater every (n) seconds determins if content should be updated.
function check()
{
new Ajax.Request(gContentUrl,{method:'get', onSuccess:'checkResponse'});
setTimeout('check();',gCheckInterval);
}
// looks for the response and determines if the div should be updated.
function checkResponse(transport)
{
var content = transport.response.Text;
if(gCurrentCheck != content) {
gCurrentCheck = content;
new Ajax.Request(gContentUrl, {method: 'get',onSuccess:function t() {
$(gUpdateDiv).innerHTML = t.responseText; /*t.response.json()*/}
});
}
}
This is the bit I dont understand
function checkResponse(transport)
{
var content = transport.response.Text;
if(gCurrentCheck != content) {
gCurrentCheck = content;
new Ajax.Request(gContentUrl, {method: 'get',onSuccess:function t() {
$(gUpdateDiv).innerHTML = t.response.json();/*t.responseText;*/}
});
}
}
Method and Issues
What is transport here and what is t? if it stores the contents of the body text from the second in gCurrentCheck and compares to transport version content then why doesn't it update if its different please which it is if the SQL has created a different page?
I did find this https://api.jquery.com/jquery.ajaxtransport/
First Answer not using Ajax
I was given a neat and JS version as an answer, which is not really what I was looking for. I was hopeful to get the one working with one with Ajax but I appreciate your efforts is very kind. I just really wanted to send a refresh to the div area so that the PHP rebuilt the page from the SQL.
I might have been missing the MIT javascript http://www.prototypejs.org/ lol but I dont think it was.
Just to help:
AJAX stands for Asynchronous JavaScript And XML. In a nutshell, it is the use of the XMLHttpRequest object to communicate with servers. It can send and receive information in various formats, including JSON, XML, HTML, and text files. ... Make requests to the server without reloading the page.
Researching
I found this Update div with the result of an Ajax-call but it did not really explain as the OP was using PHP like me not HTML. The answer was given:
$.ajax({
url: 'http://dowmian.com/xs1/getcam.php',
type: 'GET',
data: {id: <?php echo $cam_id; ?>},
success: function(responseText){
$('#update-div').html(responseText);
},
error: function(responseText){
}
});
I dont think above it answered posters question or mine as ajax is a server based push how is this relevant? as if its PHP driven the needs a refresh at server to refresh the contents not to provide new html. It is this refresh I am not interested in to re-copy PHP code elsewhere in JS as its already in my PHP. Does that make more sense?
Update
I did find a bracket missing and a set of single quotes inserted by editor. Which I have updated above but there was no significant change.
Cheers Nicolas . I am still hopeful that someone knows about Ajax as it sits underneath these technologies. I have a server side PHP file that I was hoping to use AJAX to pull just the PHP from the section it was pointing to an gUpdateDiv . As its derived from the server and created on the fly from SQL. I dont see how your answer would help push this data back in to the from the server . The $(gUpdateDiv).innerHTML was supposed to be acted upon not the whole page . What I am unsure of is how a trigger from this can update timer just this $(gUpdateDiv).innerHTML . I am also not aware if a server based refresh would do this or if the transport id provided from the file would be able to deliver just that . I think I am missing something a vital part that I dont have or have grasped yet. The reason there is two timers is effectively it checks the same file at a different point in time as its created by PHP it might be different from the first if it is i.e. the SQL data has changed, I want this to update this $(gUpdateDiv).innerHTML with the data which it compared it to the second 'Get' in the second request. It sounds, simple in practice but have got stuck comparing two versions and insuring second version gets used .
Further update placing an alert in the Javascript file did not pop up like it does here https://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_alert however the same alert in the initiating PHP worked fine and created the alert. called the same function from the main PHP nd the alert occurred so the JavaScript is running next visit F12 on the page to see if there is any warnings or errors. Ok after adding JQuery which I thought I had added this started working however It is not doing what i Expected it to do. As the contained both text and graphics created by PHP I expected this all to be updated The graphics are not the text is any ideas? .
Further to the image problems I placed an extra line to update the image however I used this too in PHP
<script type="text/javascript">
//initpage() ;
function updateArtworkDisplay() {
document.querySelector('#np_track_artwork').src = 'images/nowplaying_artwork_2.png?' + new Date().getTime();
}
</Script>
But it didnt work to update the image in php?
<div id='outer_img'><img id='#np_track_artwork' src='/images/nowplaying_artwork_2.png' alt='Playing track artwork' width='200' height='200'></div>
in js change
/ looks for the response and determines if the div should be updated.
function checkResponse(transport)
{
var content = transport.response.Text;
if(gCurrentCheck != content) {
gCurrentCheck = content;
new Ajax.Request(gContentUrl, {method: 'get',onSuccess:function t() {
$(gUpdateDiv).innerHTML = t.responseText; /*t.response.json()*/}
});
updateArtworkDisplay(); // fire up the redraw in php file.
}
}
Nearly there it does almost what it needs to apart from the redraw which is not happening
// Start Clock refresh
// uses new new Ajax.PeriodicalUpdater(
// in main fetch file to trigger the auto update of the page.
// Written by Denise Rose
var gUpdateDiv="";
var gContentURL="";
var gcheckInterval=0;
var gcheckURL = "";
var gCurrentCheck ="";
_fetchUpdater('track_data','/fetch_sql.php','/fetch_sql.php',8000);
function _fetchUpdater(updateDiv,contentURL,checkURL,checkInterval)
{
gUpdateDiv = updateDiv;
gContentURL = contentURL;
gcheckInterval = checkInterval;
gCheckURL = checkURL;
setTimeout('check();',gcheckInterval);
}
//Called by _fetchUpdater every (n) seconds determins if content should be updated.
function check()
{
new Ajax.Request(gCheckURL,{method:'get', onSuccess:'CheckResponse()'});
setTimeout('check();',gcheckInterval);
}
// looks for the response and determines if the div should be updated.
function checkResponse(transport)
{
var content = transport.response.Text;
if(gCurrentCheck != content) {
gCurrentCheck = content;
new Ajax.Request(gContentUrl, {method: 'get',onSuccess:function t() {
$(gUpdateDiv).innerHTML = t.responseText; /*t.response.json()*/}
});
$time = new Date().getTime();
new Ajax.Request('outer_img', {method: 'get',onSuccess:function s() {
$('outer_img').innerHTML = "<img id='#np_track_artwork' src='/images/nowplaying_artwork_2.png?t='"+$time+" alt='Playing track artwork' width='200' height='200'>"}
});
}
}

GIVEN UP WITH THIS PLEASE DELETE MY PERSONAL INFORMATION AND POSTSript-fetch-async-await/

Related

Load php file within javascript (AJAX or others)

I am trying to finish one page of my website the last couple of hours while achieving the following.
While clicking on a button, the following should happen
Download link appears (done - works)
The mySQL table should be opened and a counter should be incremented
As far as I got the points. Javascript cannot handle that and thus we can use AJAX or jQuery. I was already checking out different posts and websites such as:
how to execute php code within javascript
https://www.w3schools.com/js/js_ajax_database.asp
and much more. However, I guess I do have problems with the AJAX syntax and I actually don't know if the requested php files is loaded/opened or not. Especially the second link given above is almost similar to what I am searching for. However, it does not work. To check if the php file is called, I set an alert which works if I do call the file explicitly in the browser. Maybe this does not work with AJAX as I expect it. Here the code to get more familiar with the inconstency I am doing.
The page code:
<?php
echo '<div><button onclick="incrementAndDownload('testPath', 'fileName'); ">Click me</button></div>';
?>
<script>
function incrementAndDownload (link, fileName)
{
$.ajax({
url: 'openfoam/increment.php',
success: function(data) {
// Print something if necessary
}
});
//- Open the link
// window.open(arguments[0], "_blank");
//- Increment download inside mysql
//var xhttp;
//xhttp = new XMLHttpRequest();
//xhttp.open("GET", "openfoam/increment.php?foo=nana", true);
//xhttp.send();
}
</script>
The increment.php looks as follows:
<?php
echo '<script type="text/javascript" language="Javascript">
alert("Test message if the script is called...");
</script>';
// Code for accessing the mysql database and manipulate the data
//$page_id = mysql_real_escape_string(html_entities($_POST['file']));
?>
Now when I click the button, the javascript is executed (e.g., if I uncomment the window.open) this works as expected. However, as already said, the second part is to open the database via php and increment a number (counter). For any reason, I am not able to figure out where the problem is located. I am even not sure if AJAX opens the increment.php file (the alert messages never appears so I guess it is never called). Any suggestion is appreciated and I hope that this question does not just contain a fundamental small error. Thank in advance, Tobi
It's not the way the AJAX works. If you call alert() on a destination page it won't show in your browser. Your case is very basic so I will keep my solution on a basic level.
In increment.php just echo something, it can be just OK string. So when you go to increment.php page you will see only OK, nothing more, nothing less.
Then go back to your javascript and check what is your response.
$.ajax({
url: 'openfoam/increment.php',
success: function(data) {
if (data == 'OK') {
console.log('It works, sir!');
}
}
});
If you don't see a message in a console after these modifications something doesn't work. However, I think your page is executed properly, but you just don't get feedback, because you don't handle the response (data param in your case).
Check it out and don't forget to give me a feedback!🤓

Why am I getting this Internal Server Error in the Laravel Framework?

I have come across a situation that doesn't make much sense to me. Just as some background information, I'm using the Laravel framework. The page in question calls a query when the page is requested using Laravel's '->with('var', $array)' syntax. This query (which I will post later) works perfectly fine on page load, and successfully inserts dummy data I fed it.
I call this same query via an Ajax $.post using jQuery, on click of a button. However, when I do this $.post and call this query, I get an Internal Server Error every time. Everything is exactly the same, information passed included; the only difference seems to be whether or not it is called on page load or via the $.post.
Here is the error:
Below is the code that performs the query on page load:
routes.php sends the HTTP get request to a file called AppController.php
routes.php
AppController.php
The page is then made with the following array acquired from DeviceCheckoutController.php
Which then goes to DeviceCheckout.php
I am able to echo $test on the page, and it returns the ID of a new row every time the page is reloaded (which obviously mean the 'insertGetId' query worked). However, I hooked this query up to the page load just to test. What I really want to happen is on click of a button. Here is the code for that:
$("#checkoutFormbox").on('click', '#checkoutButton', function() {
var checkoutInformation = Object();
var accessories = [];
var counter = 0;
var deviceName = checkoutDeviceTable.cell(0, 0).data();
$(".accessoryCheckbox").each(function() {
//add accessory ID's to this list of only accessories selected to be checked out
if($(this).val() == "1")
{
accessories[counter] = $(this).data('id') + " ";
}
counter++;
});
checkoutInformation['deviceID'] = $(".removeButton").val(); //deviceID was previously stored in the remove button's value when the add button was clicked
checkoutInformation['outBy'] = '';
checkoutInformation['outNotes'] = $("#checkOutDeviceNotes").val();
checkoutInformation['idOfAccessories'] = 2;
checkoutInformation['dueDate'] = $("#dueDate").val();
if($("#studentIdButton").hasClass('active'))
{
checkoutInformation['renterID'] = 0;
checkoutInformation['emplid'] = 1778884;
console.log(checkoutInformation);
$.post("http://xxx.xxx.xxx.xxx/testing/public/apps/devicecheckout-checkoutdevices", {type: "checkoutDeviceForStudent", checkoutInformation: checkoutInformation}, function(returnedData) {
alert(returnedData);
});
}
});
Which is also then routed to AppController.php, specifically to the 'checkoutDeviceForStudent' part of the switch statement:
And then back to that query that is shown previously in DeviceCheckout.php
Finally, here is my DB structure for reference:
Any explanation as for why this would be happening? Also, any Laravel or other general best practice tips would be greatly appreciated as I'm inexperienced in usage of this framework and programming overall.
Sorry for such a long post, I hope there is enough information to diagnose this problem. Let me know if I need to include anything else.
Edit: Included picture of error at the top of the page.
Everything is exactly the same, information passed included
No, it isn't. If it was exactly the same you wouldn't be getting the error you're getting.
These sorts of issues are too difficult to solve by taking guesses at what the problem might be. You need to
Setup your system so Laravel's logging errors to the laravel.log file
Setup you PHP system so errors Laravel can't handled are logged to your webserver's error log (and/or PHP's error log)
Put Laravel in debug mode so errors are output the the screen, and the view the output of your ajax request via Firebug or Chrome
Once you have the actual PHP error it's usually pretty easy to see what's different about the request you think is the same, and address the issue.
I found a resolution to my problem after some advice from a friend; much easier than I anticipated and much easier than any solution that has been offered to me here or other places.
Essentially, what I needed to do was place a try, catch clause in my model function, and then if an exception is encountered I store that in a variable, return it, and use console.log() to view the exception. Here is an example to emulate my point:
public function getUserFullname($userID)
{
try
{
$myResult = DB::connection('myDatabase')->table('TheCoolestTable')->select('fullName')->where('userID', '=', $userID)->get();
return $myResult;
}
catch(Exception $e)
{
$errorMessage = 'Caught exception: ' . $e->getMessage();
return $errorMessage;
}
}
And then on the View (or wherever your model function returns to), simply console.log() the output of your POST. This will display the results of the successful query, or the results of the Exception if it encountered one as opposed to an unhelpful Internal Server Error 500 message.

Execute javascript inside the target of an Ajax Call Drag and Drop Shopping Cart without Server language

Well i wanna create an Ajax Drag and Drop Shopping cart using only javascript and ajax. Currently i'm using the example in this page as a stepping stone. Right now it's only with local jquery and it works fine but i want to make the cart work with ajax calls. Note that i do not want to use a server side language( like php, rubby, asp etc), only html and javascript.
My initial thought was that at the $(".basket").droppable i should add an ajax call to another html page containing the "server logic" in javascript, execute in that file all the necessary steps( like reading the get variables (product name, product id and quantity), set a cookie and then return an ok response back. When the server got the "ok" response it should "reload" the cart div with the updated info stored inside the cookie.
If this was with php i would know how to do it. The problem is that as far as i know, you can execute javascript once it reaches the DOM, but how can you execute that js from inside the page that isbeing called upon ? ( thanks to Amadan for the correction)
I've thought about loading the script using $.getScript( "ajax/test.js", function( data, textStatus, jqxhr ).. but the problem with that is that the url GET variables i want to pass to the "server script" do not exist in that page.
I havent implemented all the functionality yet as i am stuck in how to first achieve javascript execution inside an ajax target page.
Below is a very basic form of my logic so far
// read GET variables
var product = getQueryVariable("product");
var id = getQueryVariable("id");
var quantity= getQueryVariable("quantity");
//To DO
//--- here eill go all the logic regarding cookie handling
function getQueryVariable(variable) {
var query = window.location.search.substring(1);
var vars = query.split("&");
for (var i=0;i<vars.length;i++) {
var pair = vars[i].split("=");
if (pair[0] == variable) {
return pair[1];
}
}
alert('Query Variable ' + variable + ' not found');
}
Any help regarding this matter will be appreciated.
Note: Logic in simple words:
1)have an html page with products+cart
2)Have an "addtocart.html" with the "Cart Server Logic"( being the target of the ajax call when an item is dropped into the product.)
If you have some other idea on this, please enlighten me :)
thanks in advance
Foot Note-1:
if i try loading the scipt using
$("#response").load("ajax/addtocart.html?"+ $.param({
product: product,
id: id,
quantity:quantity
})
);
i get the alert about not being able to find the url parameters( something that i thing is normal as because the content is being loaded into the initial page, from which the request is started, there are no get parameters in the url in the first place)
The problem is that as far as i know, you cannot execute javascript contained in the target of an ajax call, as that page never reaches the browser interpreter.
This is either incorrect or misleading. The browser will execute any JavaScript that enters DOM. Thus, you can use $.load to load content and execute code at the same time. Alternately, you can use hacked JSONP to both execute code and also provide content as a JSON document.
EDIT: Yes, you can't get to the AJAX parameters from JavaScript. Why do you want to? Do you have a good reason for it, or is it an XY problem?
The way I'd do it is this:
$('#response').load(url, data, function() {
onAddedToCart(product, id, quantity);
});
and wrap your JS code in your HTML into the onAddedToCart function.
Depending on what exactly you're doing, it could be simplified even further, but this should be enough to cover your use case.

How to store HTML attributes that trigger javascript commands properly to mysql using ajax?

I have problems when saving html5 data from a page into mysql through an ajax request and trying to retrieve it back with ajax. HTML attributes that trigger some javascript such as
<onload> or <iframe> will be stored as <on<x>load> and <if<x>rame> in the database and thus screw up the page when loading it.
Here's a short description of what I am trying to accomplish: I want registered users to have the ability to highlight text on my site and get the highlighted text back after refreshing the page, relogging etc.
What I have done so far: I implemented a javascript highlight library on my server that allows users to highlight text. That works well.
By clicking a button, those data are then saved into mysql through jquery ajax post. See specific code here:
Javascript
$(document).ready(function() {
//saves highlighted data in var "highlighted"
$('#savehighlights').click(function() {
var highlighted = $('.tabcontent.content1').html();
//send data to server
$.ajax({
url: 'highlight.php',
type: 'POST',
data: {highlighted: highlighted},
dataType: 'html',
success: function(result) {
console.log(result);
}
});
});
Saving the data to mysql works generally, but it looks as if certain commands are disabled through the process (e.g. onload becomes on<x>load5). The data are stored in the database as longtext and utf8_bin. I also tried blob, but problem remains. I also tried different dataTypes with Ajax such as 'text' and 'script'. 'Text' causes the same problem and 'script doesn't work at all. I also tried the ajax .serialize function, but no luck either.
I really don't know what to do about it and I am not sure what is causing the problem, Ajax or mysql? I was searching the web for an answer, including many articles in stackoverflow (which normally always give me the answer), but this time I am stuck. Either I don't know enough about it to look for the right question, or I just don't have any luck this time. So, any help would be greatly appreciated.
I was requested to add some more information. Here it is:
I am actually doing this on my local server (localhost) with XAMP, so security issues should not be a problem, right? If it is of any help, I am doing this in a Tiki Wiki CMS. The php script that is called through ajax (highlight.php) is the following:
require_once ('tiki-setup.php');
include_once ('lib/highlights/highlightslib.php');
$highlighted = $_POST['highlighted'];
$highlightslib->save_highlights($user, $highlighted);
The highlightslib library is here:
if (strpos($_SERVER["SCRIPT_NAME"], basename(__FILE__)) !== false) {
header("location: index.php");
exit;
}
class HighlightsLib extends TikiLib
{
function save_highlights($user, $highlighted) {
$saveHighlights = $this->table('tiki_user_highlights');
$saveHighlights->insert
(array(
'user' =>$user,
'highlightId' =>'',
'data' =>$highlighted,
'created' =>$this->now,
)
);
return true;
}
};
$highlightslib = new HighlightsLib;

I want to request JSON inside of a WordPress page

For the last few hours I've been trying to set up this http://code.google.com/apis/books/docs/dynamic-links.html on a WordPress blog. Google's API sends back a JSON response (which is supposed to be "put" into _GBSBookInfo variable). However, that variable never is assigned so my javascript callback function explodes saying the variable doesn't exist. So far, all of my javascript is in the WordPress header.
I tried this outside of WordPress and it works fine.
This is the static page:
<script src="http://books.google.com/books?bibkeys=0307346609&jscmd=viewapi&callback=response_handler">
This is the handler:
function response_handler(data) {
var bookInfo = _GBSBookInfo["0307346609"]; // the var that doesn't exist
document.getElementById("test123").innerHTML = bookInfo.thumbnail_url;
}
Thanks for any help in advance, WordPress has been extremely frustrating by limiting so much! If I'm doing anything stupid please say so, I'm a new javascript programmer.
EDIT:
I've used firebug so far to identify the problem to be: the _GBSBookInfo variable never gets "created" or "exists". I'm not sure how javascript works at this level. Hopefully this helps.
ERRORS:
Error: _GBSBookInfo is not defined
Line: 79
Try replacing _GSBookInfo with data, like so:
function response_handler (data) {
var bookInfo = data["0307346609"];
document.getElementById("test123").innerHTML = bookInfo.thumbnail_url;
}
Based on your post, google returns this:
response_handler({
"0307346609": {
"bib_key":"0307346609",
....
"thumbnail_url":"http://bks2.books.google.com/books?somethumbnailstuff"
}
});
... so the above code should work for you.

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