'Edit' function for forum posts and such - php

Question

I was looking online for a script that demonstrates how I would go about making it possible for users on my site able to edit fields and such, but I could not find anything about it. So I was wondering if someone could explain to me how it works or just demonstrate with a script? To make it clear, I want users to be able to edit stuff that they've submitted by simply clicking 'edit' and pressing a button to update whatever it was they changed.
Edit: I forgot to mention that what's been changed should update a table in a MySQL database.

Answer 1

You need 2 PHP files to do this. You could use a single file but the concept is easier to explain this way.
A form that will load the database content into the fields where users can then edit the values and then submit them for change by pressing a button once done.
A file that receives the changed information and updates the database.
Here is a code example for the first file:
<?php
// connect to SQL
$dbcnx = #mysql_connect("localhost", "db_name", "password");
if (!$dbcnx) {
echo( "<P>Unable to connect to the database server at this time.</P>" );
exit();
}
// connect to database
$dbcon = #mysql_select_db("db_table", $dbcnx);
if (!$dbcon) {
echo( "<P>Unable to locate DB table at this time.</P>" );
exit();
}
#data preparation for the query
$id = intval($_GET["id"]);
# selects title and description fields from database
$sql = "SELECT * FROM table_name WHERE id=$id";
$result = mysql_query($sql) or die(mysql_error());
# retrieved by using $row['col_name']
$row = mysql_fetch_array($result);
?>
<h3>Edit</h3>
<form action="save_edit.php" enctype="multipart/form-data" method="post" name="myForm" />
<table>
<tr>
<td><b>Title</b></td>
<td><input type="text" size="70" maxlength="100" name="title" value="<?php echo $row['title'] ?>"></td>
</tr>
<tr>
<td><b>Description</b></td>
<td><textarea cols="80" rows="18" name="description"><?php echo $row['description']; ?></textarea></td>
</tr>
</table>
<input type="hidden" name="id" value="<?php echo $id; ?>" />
<input name="enter" type="submit" value="Edit">
</form>
<?php
mysql_close($dbcnx);
?>
And here is an example of code for the second file where it receives the changes made by the user and updates the database.
<?php
// connect to SQL
$dbcnx = #mysql_connect("localhost", "db_name", "password");
if (!$dbcnx) {
echo( "<P>Unable to connect to the database server at this time.</P>" );
exit();
}
// connect to database
$dbcon = #mysql_select_db("db_table", $dbcnx);
if (!$dbcon) {
echo( "<P>Unable to locate DB table at this time.</P>" );
exit();
}
#data preparation for the query
$id = intval($_POST["id"]);
foreach ($_POST as $key => $value) $_POST[$key] = mysql_real_escape_string($value);
$sql = "UPDATE table_name SET
title='$_POST[title]',
description='$_POST[description]',
WHERE id=$id";
if (!mysql_query($sql,$dbcnx)) {
die('Error: ' . mysql_error());
}
mysql_close($dbcnx);
header ("location: http://www.domain.com/url_to_go_to_after_update");
?>

Answer 2

If you just need an idea how to create a basic edit form in PhP, that's easy enough. When they click the edit button take them to a new form. Pull the content from the database, using whatever database accessing api you are, and then initialize the field with it. For example, where $content has the content of the field:
echo '<textarea name="content">'.htmlspecialchars($content).'</textarea>';
When they submit the form, take whats now in the field and use it to update the table. It's the same as the original insert script, except that you use update statements instead of insert.

Answer 3

I'm not sure I understood what you said. If you want a way to edit things in place, you can use this jQuery plugin: Jeditable (with Ajax).

Answer 4

To extend Daniel's code a bit
<?php
$filename = "file.txt";
if ($_SERVER['REQUEST_METHOD'] == 'POST']) {
file_put_contents($filename, $_POST['content']);
header("Location: ".$_SERVER['PHP_SELF']);
exit;
}
$content = htmlspecialchars(file_get_contents($filename));
?>
<form method="POST">
<textarea name="content"><?php echo $content?></textarea><br>
<input type="submit">
</form>