I have created a script to count down whatever value I submit into a form and then output "the submitted value + the date of the moment I clicked on the submit button" as a result.
But now I want to store the result into my database every time I use the form by using SQL query and then echo all of these results in another page named "log.php" using SELECT SQL query.
var timelog = [];
function myF() {
countdown(s);
log = document.getElementById("log").innerHTML = s + 'at ' + new Date();
timelog.push(log);
}
function logged() {
document.getElementById("timeloggg").innerHTML = timelog;
}
I have tried to assign the result to a variable, but obviously, I cant use this variable outside of the script.
With some googling, I was told to use Ajax, but sadly I couldn't figure out how to insert the data using ajax, because all of the code examples out there are only about calling data from the database.
So any advice on how to insert the result into my database? I'm still a beginner so please explain in detail if you don't mind.
It is possible, of course, to insert data into your database from client side js, BUT DONT! I can't think of a way to do it that would not expose your database credentials, leaving you open to malicious actors.
What you need to do is set up a php script on your server, then send the data (either by POST or GET) you want inserted to that with an xhr request, and let that php script do the insert. HOWEVER, there is quite a bit to securing even that. Google "how to sanitize mysql inputs in php" and read several articles on it.
Depending on what you need to do, you can sanitize the inputs yourself, but the recommended way to do it is with prepared statements, which you will need to read the documentation for your specific implementation, whether it's mysqli or pdo in mySQL or some other library (say if you're using SQL, postGRE, Oracle, etc).
HTH
=================================================
Here is how to do it in js, BUT DONT DO THIS, unless you are never going to expose this code outside of your local computer.
var connection = new ActiveXObject("ADODB.Connection");
var connectionstring = "Provider=host;Data Source=table;User Id=user;Password=pass;";
connection.Open(connectionstring);
var rs = new ActiveXObject("ADODB.Recordset");
var sql = {{your sql statement}};
rs.Open(sql, connection);
connection.close;
==============================================
For php, do something like this, replacing host, user, pass, db with your actual credentials and hostname and database:
$db = new mysqli({host}, {user}, {pass}, {database});
if($db->connect_errno > 0){ die ("Unable to connect to database [{$db->connect_error}]"); }
to set the connection. If this is a publicly accessible php server, then there are rules about how to set up the connection so that you don't accidentally expose your credentials, but I'm going to skip that for now. You would basically save this into a file that's not accessible from the outside (above the document root, for instance) and then include it, but database security is a complex topic.
To get the values you passed in the query string of your ajax call:
$val1 = $_GET['val1'];
$val2 = $_GET['val2'];
Then to do the insert with a parameterized query:
$query = $db->prepare("
INSERT INTO your_table (field1, field2)
VALUES (?, ?)
");
$query->bind_param('ss', $val1, $val2);
$query->execute();
Now, here you're going to have to look at the documentation. 'ss' means that it's going to treat both of those values you're inserting as strings. I don't know the table set up, so you'll have to look up the right code for whatever you are actually inserting, like if they were integers, then 'ii', or 'si' would mean the first value was a string and the second one was an int.
Here are the allowed values:
i - integer
d - double
s - string
b - BLOB
but look at the documentation for prepared statements anyway. I used msqli in this example.
You might want to check Ajax requests.
I would suggest to start here.
What you will do is basically create asynchronous requests from javascript to a php file on your server.
Ajax allows web pages to be updated asynchronously by exchanging small
amounts of data with the server behind the scenes. This means that it
is possible to update parts of a web page, without reloading the whole
page.
Related
As a follow-up to my last question, I have run into another problem. I am making a project on google homepage replica. The aim is to show search results the same as google and store the search history on a database. To show results, I have used this javascript:-
const q = document.getElementById('form_search');
const google = 'https://www.google.com/search?q=';
const site = '';
function google_search(event) {
event.preventDefault();
const url = google + site + '+' + q.value;
const win = window.open(url, '_self');
win.focus();
}
document.getElementById("s-btn").addEventListener("click", google_search)
To create my form, I have used the following HTML code:-
<form method="POST" name="form_search" action="form.php">
<input type="text" id="form_search" name="form_search" placeholder="Search Google or type URL">
The terms from the search bar are to be sent to a PHP file with the post method. I have 2 buttons. Let's name them button1 and button2. The javascript uses the id of button1 while button2 has no javascript and is simply a submit button.
The problem is that when I search using button1, the search results show up but no data is added to my database. But when I search using button2, no results show up( obviously because there is no js for it) but the search term is added to my database. If I reverse the id in javascript, the outcome is also reversed. I need help with making sure that when I search with button1, it shows results and also saves the data in the database. If you need additional code, I will provide it. Please keep your answers limited to javascript, PHP, or HTML solutions. I have no experience with Ajax and JQuery. Any help is appreciated.
Tony since there is limited code available so go with what you had stated in your question.
It is a design pattern issue not so much as so the event issue.
Copy pasting from Wikipedia "software design pattern is a general, reusable solution to a commonly occurring problem within a given context in software design. It is not a finished design that can be transformed directly into source or machine code. Rather, it is a description or template for how to solve a problem that can be used in many different situations. Design patterns are formalized best practices that the programmer can use to solve common problems when designing an application or system."
So here is how things play out at present;
forms gets submitted to specific URL i.e. based on action attribute
Requested page gets Query sting in php and lets you play around with it
then from there on .....
3. either you get results from database and return response
4. or you put search request into database and return success response
Problem statement
if its 3 then search request is not added to database if its 4 then results in response to search request are not returned.
Solution
you need to combine both 3 and 4 in to one processing block and will always run regardless of the search query is.
So our design pattern could use mysql transaction so whole bunch of queries would run a single operation example
$db->beginTransaction(); // we tell tell mysql we will multiple queries as single operation
$db->query('insert query');
$results= $db->query('search query');
$db->commit(); // if we have reached to this end it means all went fine no error etc so we commit which will make database record insert query into database. If there were errors then mysql wont record data.
if($results) {echo $results;} else {echo 'opps no result found';}
slightly more safe version
try {
$db->beginTransaction(); // we tell tell mysql we will multiple queries as single operation
$db->query('insert query');
$results= $db->query('search query');
$db->commit(); // if we have reached to this end it means all went fine no error etc so we commit which will make database record insert query into database. If there were errors then mysql wont record data.
if($results) {echo $results;} else {echo 'opps no result found';}
} catch (\Throwable $e) {
// An exception has been thrown must rollback the transaction
$db->rollback();
echo 'oho server could not process request';
}
We have effectively combined two query operation into one always recording into database and always searching in database.
Before I get to the question, let me explain how we have things set up.
We have a proxy.php file, in which class Proxy is defined with functions that call upon a rest for creating/editing/getting Wordpress posts, fields etc.
Then, we have a proxyhandler.php, in which Proxy class is initialized and serves as a handle between proxy.php and a javascript file.
In javascript file we have an ajax call to proxyhandler.php in which we send our secret and other data.
Now, the problem arises here:
We define the secret through wp_localize_script, by using md5 custom string + timestamp. We send the encripted string and timestamp through ajax to proxy handler, where we use the previous (hardcoded inside proxyhandler) string and timestamp to generate a md5 string again, and check the one sent against the one generated. If they are the same, we continue by doing whatever was requested, if they dont fit, we just return that the secret didn't match.
Now, the real issue comes here - by using wp_localize_script, the variable for the secret is global and as such, anyone can utilize it via dev tools and can send any ajax request to proxyhandler that they want.
What would be the proper procedure to make it more secure? We've thought of doing this:
Instead of using wp_localize_script, we put the script inside a php file, we define the secret using a php variable and then simply echo the secret file into ajax. Would this be viable, or are there any other ways?
Instead of sending an encrypted string in global scope, then check against it, you should use nonce in your AJAX request:
var data = {
action: 'your_action',
whatever_data: who_know,
_ajax_nonce: <?= wp_create_nonce('your_ajax_nonce') ?>
};
Then, use check_ajax_refer() to verify that nonce:
function your_callback_function()
{
// Make sure to verify nonce
check_ajax_refer('your_ajax_nonce');
// If logged in user, make sure to check capabilities.
if ( current_user_can($capability) ) {
// Process data.
} else {
// Do something else.
}
...
}
Depend on the AJAX METHOD, you can use $_METHOD['whatever_data'] to retrieve who_know data without needing to use wp_localize_script().
Also remember that we can allow only logged in users process AJAX data:
// For logged in users
add_action('wp_ajax_your_action', 'your_callback_function');
// Remove for none logged in users
// add_action('wp_ajax_nopriv_your_action', 'your_callback_function');
The final thing is to make sure NONCE_KEY and NONCE_SALT in your wp-config.php are secure.
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 } );
I am trying to use javascript in my CI view to update (without refresh) a data model every 2 seconds, for my use case where the database contents can be changed by other users.
<script type="text/javascript">
var refreshFunc = setInterval(function() {
<?php
$this -> load -> model('m_cube', '', TRUE);
$stamp = $this -> $m_cube -> stamp();
?>
var stamp = "<?php echo $stamp; ?>";
console.log(stamp);
}, 2000);
refreshFunc;
</script>
I am using JS setInterval to create the 2 second loop, and calling the CI model to retrieve data from the Postgresql database. In the simplified code sample, it's just asking the DB for a timestamp. The problem is that the timestamp written to console doesn't update - something is stuck.
2013-10-21 14:35:54.168-04
2013-10-21 14:35:54.168-04
2013-10-21 14:35:54.168-04
...
Same behavior when querying a table of real data - it doesn't return up-to-date values.
Why does the model access a "frozen" version of the DB?
It's not stuck or "frozen", it's that you had a bit of confusion on what comes before and what after.
I don't see you using AJAX, so by the time your php has been processed (i.e, the data fetched from the db and assigned to $stamp) the page - html, css and javascript too - are yet to be generated and served by the server, nor outputted by the browser.
This means that inside your setInterval you always have the same value, which has been already generated, and thus you keep reprinting the same string.
If you want a continue update, you need to keep requesting the data to the server, and that's where AJAX (Asynchronous JavaScript and XML) can be handy since it runs as a separate request from the main one, so you can work on two different "levels" and fetch content while the rest of the page remains static (already served and outputted).
If you're using jQUery you can look into $.ajax(), which makes this kind of things pretty easy.
When this script runs at the server it fetches the model data and replace the <?php ?> tags with the results. So when it comes to client browser, it doesn't contact server every 2 seconds, but logs the stamp value every 2 seconds. If you want it to be updated you should consider using Ajax technology.
I'm trying to use HTML 5's local database feature on a Mac Dashboard widget.
I'm programming in Dashcode the following javascript:
if (window.openDatabase)
{
database = openDatabase("MyDB", "1.0", "Sample DB", 1000);
if (database)
{
...database code here...
}
}
Unfortunately the database-variable remains always null after the call to openDatabase-method. I'm starting to think that local databases are not supported in Widgets...
Any ideas?
/pom
No you will not be able to do the above. And even if you could then you would not be able to distribute the widget without distributing the database assuming it was a MySQL or SGLite. (not sure what you mean by HTML 5's local Db.
here are a number of ways round this:-
You can add a data source which can be a JSON file, or an XML file or and RSS feed. So to do this with JSON for example you would write a page on a server in PHP or something that accessed a database so that when the URL was called the result was a JSON string. Take the JSON string and parse it and use it in the Widget. This will let you get data but not save it.
Another way would be to use the user preferences. This allows you to save and retrieve data in the individual widget.
So
var preferenceKey = "key"; // replace with the key for a preference
var preferenceValue = "value"; // replace with a preference to save
// Preference code
widget.setPreferenceForKey(preferenceValue, preferenceKey);
You can then retrieve it with
var preferenceForKey = "key"; // replace with the key for a preference
// Preference code
preferenceForKey = widget.preferenceForKey(preferenceForKey);
The external call, you could also use REST will let you read any amount of data in and the preferences will let you save data for later reuse that will survive log out's and shut downs.
The Apple site has a lot of information about Widgets and tutorials as well thjat are worth working through.
Hope this helps.