"Undefined index" when quoting array key - php

I have a form in index.php
<?php
echo '<form action="update_act.php" method="POST">';
echo '<input type="submit" name="'.$row['act_name'].'" value="edit">
echo </form>
?>
Here $row['act_name'] is a value fetched from database.
My update_act.php file is
<?php
echo "Old Activity Name : ".$_POST['$row[\'act_name\']'];
?>
But I am getting an error Undefined index: $row['act_name'] in C:\wamp\www\ps\activity\update_act.php.
I want to have different names for different submits but I am not able to get its value in another page. Is there any way for it?

I don't exactly know, what you're trying to do, but if the value of variable $row['act_name'] is same in both of the cases (form page and update script), then you can access to that this way:
echo "Old Activity Name : ".$_POST[$row['act_name']];

PHP only substitutes variables enclosed in double quotes " . What you want is:
echo "Old Activity Name : ". $_POST[$row['act_name']]
But your whole form does not make any sense. The output you get would be:
Old Activity Name : edit
because this is the value of the submit button.
Can you please clarify your question, what do you want to achieve? Here are some thoughts from my side:
Maybe what you want is more like:
<form action="update_act.php" method="POST">;
<input type="hidden" name="act_name" value="<?php echo $row[act_name] ?>" />
<input type="submit" name="submit" value="edit">
</form>
// ---- other file ---
<?php
echo "Old Activity Name : ".$_POST['act_name'];
?>
Why do you want to have different names for different submits ?
Do you want to differentiate between different actions? If so, it is easier you the buttons have the same name and you check against their values, e.g.:
<form action="update_act.php" method="POST">;
<input type="submit" name="submit" value="edit">
</form>
<form action="update_act.php" method="POST">;
<input type="submit" name="submit" value="delete">
</form>
and then
<?php
if($_POST['submit'] == 'edit') {
}
else if ($_POST['submit'] == 'delete') {
}

Use $_POST[$row['act_name']].

echo "Old Activity Name : ".$_POST['$row[\'act_name\']'];
should be
echo "Old Activity Name : ".$_POST["$row[act_name]"];
or
echo "Old Activity Name : ".$_POST[$row[act_name]];

Related

Can't use a form's value in a different php file

Having issues with using a form's value in a different php file:
my firstpage.php
<form method="post">
<input type="radio" name="rdbbtn" value="1"> One
<input type="radio" name="rdbbtn" value="2"> Two
</form>
my secondpage.php is here
<?php
include("firstpage.php");
$result = $_POST['rdbbtn'];
if ($result == "1") {
echo 'thirdpage.php';
}
else {
echo 'fourthpage.php';
}
?>
problem:
Notice: Undefined index: rdbbtn in
how come I can't use "rdbbtn"? Should I have something like
$rdbbtn = $_POST['rdbbtn'];
in secondpage.php? Tried this but didn't solve my problem.
firstpage.php and secondpage.php are in the same directory.
Probably it's some pretty obvious thing that I don't see...thanks!
EDIT: I have accepted pradeep's answer as that helped me the most to figure what the problem should be. would like to say thank you for everybody else showing up here and trying to help!
When you change current page it reset the value and $_POST is empty.
You can try with set form action to next page . It will work
<form method="post" action="secondpage.php">
<input type="radio" name="rdbbtn" value="1"> One
<input type="radio" name="rdbbtn" value="2"> Two
<input type="submit" name="" value="Next">
</form>
Other wise you can make a function in a class and set each page action
to this function.
And set your each form data to session.
Finally when you change the page you read data form session.
Class FormAction{
public function setFormDataToSession(){
if(isset($_POST['rdbbtn']){
$_SESSION['rdbbtn'] = $_POST['rdbbtn'];
}
}
}
In your page simply get the session value.
echo $_SESSION['rdbbtn'];
Should be like this :
Check with isset method in
<?php
include("firstpage.php");
$result = isset($_POST['rdbbtn']) ? $_POST['rdbbtn'] : NULL;
if ($result == 1) {
echo 'thirdpage.php';
}
else {
echo 'fourthpage.php';
}
?>
and your form should be like this :
<form method="post">
<input type="radio" name="rdbbtn" value="1"> One
<input type="radio" name="rdbbtn" value="2"> Two
<input type="submit" name="submit" value="submit">
</form>
Sorry for not being able to comment in this post(less reputations). But seems like you are asking about storing the variables of the session. This way you can use the variables for a whole session. Just start the session by putting session_start() in the very beginning of secondpage.php file and then you can access the variables at any time during the session by simply calling $_SESSION['rdbutton] in any page like fourthpage.php or anything. Just make sure u put the session_start() at the top of each page where you want to use the variables. Don't forget the semicolons at the end. 😜 Hope this helps.

use $_GET['']; value inside $_POST[''] and submit it to the same page and display in the same page

i am new to php and while i am practing i came across a problem. actually,i have two files index1.php and index2.php. in index1.php i have a link with a unique id as
<a href="index2.php?companyid=<?php echo $row('company_id');?>>details</a>
i have got this value in index2.php as
if(isset($_GET['companyid'])){
$companyid = $_GET['companyid'];
}
now i have a search form in the index2.php as
<form method="POST" action="index2.php">
<input type="text" name="search">
<button type="submit" name="submit">submit</button>
</form>
now on button click i want the search results be displayed in the same page as
'index2.php?companyid=$companyid'
but some how if i try to use $_POST['submit']; in the same page it takes me to index2.php and instead of index2.php?companyid=$companyid and also it throws error as undefined index of $companyid if i don't use $_POST['submit']; and echo $companyid; it gives value and works fine. all i want is that to use $companyid' value inside ``$_POST['submit']; as and display the result in the same url as before
if(isset($_POST['submit']){
$companyid //throws an error index of company id
}
any help will be appreciated
First off, it looks like you are not using the company id in the form itself, so it will not be submitted as part of the the POST. You could possibly use:
<form method="POST" action="index2.php">
<?php if (isset($companyid)): ?>
<input type="hidden" name="companyid" value="<?= $companyid; ?>">
<?php endif; ?>
<input type="text" name="search">
<button type="submit" name="submit">submit</button>
</form>
But you would probably also need to change your logic to:
if(isset($_POST['companyid'])){
$companyid = $_POST['companyid'];
}else if(isset($_GET['companyid'])){
$companyid = $_GET['companyid'];
}
As Josh pointed out in the comments, PHP is not able to remember your previous GET request but this can easily be solved by altering the action attribute of the form element. By doing this you can pass on the previous data. This would look a little something like this:
<form method="POST" action="index2.php?companyid=<?php echo $companyid;?>">
<input type="text" name="search">
<button type="submit" name="submit">submit</button>
</form>
This way you will be redirected to index2.php with the URL parameters present and you will be able to retrieve both search and companyid using $_POST and $_GET or use $_REQUEST for both.

Send value of submit button when form gets posted

I have a list of names and some buttons with product names. When one of the buttons is clicked the information of the list is sent to a PHP script, but I can't hit the submit button to send its value. How is it done?
I boiled my code down to the following:
The sending page:
<html>
<form action="buy.php" method="post">
<select name="name">
<option>John</option>
<option>Henry</option>
<select>
<input id='submit' type='submit' name='Tea' value='Tea'>
<input id='submit' type='submit' name='Coffee' value='Coffee'>
</form>
</html>
The receiving page: buy.php
<?php
$name = $_POST['name'];
$purchase = $_POST['submit'];
//here some SQL database magic happens
?>
Everything except sending the submit button value works flawlessly.
The button names are not submit, so the php $_POST['submit'] value is not set. As in isset($_POST['submit']) evaluates to false.
<html>
<form action="" method="post">
<input type="hidden" name="action" value="submit" />
<select name="name">
<option>John</option>
<option>Henry</option>
<select>
<!--
make sure all html elements that have an ID are unique and name the buttons submit
-->
<input id="tea-submit" type="submit" name="submit" value="Tea">
<input id="coffee-submit" type="submit" name="submit" value="Coffee">
</form>
</html>
<?php
if (isset($_POST['action'])) {
echo '<br />The ' . $_POST['submit'] . ' submit button was pressed<br />';
}
?>
Use this instead:
<input id='tea-submit' type='submit' name = 'submit' value = 'Tea'>
<input id='coffee-submit' type='submit' name = 'submit' value = 'Coffee'>
The initial post mentioned buttons. You can also replace the input tags with buttons.
<button type="submit" name="product" value="Tea">Tea</button>
<button type="submit" name="product" value="Coffee">Coffee</button>
The name and value attributes are required to submit the value when the form is submitted (the id attribute is not necessary in this case). The attribute type=submit specifies that clicking on this button causes the form to be submitted.
When the server is handling the submitted form, $_POST['product'] will contain the value "Tea" or "Coffee" depending on which button was clicked.
If you want you can also require the user to confirm before submitting the form (useful when you are implementing a delete button for example).
<button type="submit" name="product" value="Tea" onclick="return confirm('Are you sure you want tea?');">Tea</button>
<button type="submit" name="product" value="Coffee" onclick="return confirm('Are you sure you want coffee?');">Coffee</button>
To start, using the same ID twice is not a good idea. ID's should be unique, if you need to style elements you should use a class to apply CSS instead.
At last, you defined the name of your submit button as Tea and Coffee, but in your PHP you are using submit as index. your index should have been $_POST['Tea'] for example. that would require you to check for it being set as it only sends one , you can do that with isset().
Buy anyway , user4035 just beat me to it , his code will "fix" this for you.
Like the others said, you probably missunderstood the idea of a unique id. All I have to add is, that I do not like the idea of using "value" as the identifying property here, as it may change over time (i.e. if you want to provide multiple languages).
<input id='submit_tea' type='submit' name = 'submit_tea' value = 'Tea' />
<input id='submit_coffee' type='submit' name = 'submit_coffee' value = 'Coffee' />
and in your php script
if( array_key_exists( 'submit_tea', $_POST ) )
{
// handle tea
}
if( array_key_exists( 'submit_coffee', $_POST ) )
{
// handle coffee
}
Additionally, you can add something like if( 'POST' == $_SERVER[ 'REQUEST_METHOD' ] ) if you want to check if data was acctually posted.
You can maintain your html as it is but use this php code
<?php
$name = $_POST['name'];
$purchase1 = $_POST['Tea'];
$purchase2 =$_POST['Coffee'];
?>
You could use something like this to give your button a value:
<?php
if (isset($_POST['submit'])) {
$aSubmitVal = array_keys($_POST['submit'])[0];
echo 'The button value is: ' . $aSubmitVal;
}
?>
<form action="/" method="post">
<input id="someId" type="submit" name="submit[SomeValue]" value="Button name">
</form>
This will give you the string "SomeValue" as a result
https://i.imgur.com/28gr7Uy.gif

PHP Delete record from database MySql

I need to delete a record, in this case a categories from my forum, from the database based on its id.
<?php
if(isset($_SESSION['signed_in']) && $_SESSION['user_level'] == 1)
{
?>
<td>
<form method="post">
<input type="hidden" value="<?= ['cat_id']; ?>">
<input type="submit" name="submit" value="Remover" />
</form>
<?php
if(isset($_POST['submit']))
{
mysql_query("DELETE FROM categories where cat_id = 'cat_id'");
}
?>
</td>
<?php
}
?>
i cant get a "good" way to do it... :(
EDIT: This is for a programming lesson not a real forum!!
Your HTML Input Field needs a name so it can be identified by your PHP.
Then, in your Code Block where you attempt to delete the category, you need to acces the category id using the $_POST array.
Another thig you want to do is read up onj the dangers of SQL injections.
If you're just playing around with PHP and MySQL at the moment: Go Ahead. But if you actually want to develop, maybe you should read up on a few other things as well, even if it seems like overkill at first: PHP The Right Way.
Nontheless, try this:
<?php
if(isset($_SESSION['signed_in']) && $_SESSION['user_level'] == 1)
{
?>
<td>
<form method="post">
<input type="hidden" name="hid_catid" id="hid_catid" value="<?php echo $cat_id; ?>">
<input type="submit" name="submit" value="Remover" />
</form>
<?php
if(isset($_POST['submit']))
{
$query = "DELETE FROM categories where cat_id = '".(int)$_POST['hid_catid']."'";
mysql_query($query);
}
?>
</td>
<?php
}
?>
--> hidden field should have name and id to use
--
Thanks
Your hidden input field needs a name to be accessable after the post. Also I am not sure if ['cat_id'] is the correcty way to reference this variable. Where does it come from?
<form method="post">
<input type="hidden" name="cat_id" value="<?= $cat_id ?>">
<input type="submit" name="submit" value="Remover" />
</form>
Then your query has to look like this to correctly grab the id from the post.
mysql_query("DELETE FROM categories where cat_id = " . mysql_real_escape_string($_POST['cat_id']));

Session variable not working

I am using one session variable in my php page. As per my infomation, it is accessible throughout the program and it is, but problem is that it is showing different value for the same variable at different place in php page?
the code is as follows
<html><body>
<?php session_start();
if(!isset($_SESSION['x']))
$_SESSION['x']=1;
echo "X=". $_SESSION['x'];
?>
<form>
<input type="submit" name="save" value="save" />
</form>
<?php
if (isset($_GET['save']))
{
if(isset($_SESSION['x']))
$_SESSION['x'] = $_SESSION['x']+1;
echo $_SESSION['x']."<br>";
}
else
echo "no submit";
?>
</body></html>
value becomes different before and after submit button click? Please tell me why it is so?
thanks in advavnce.
You are redeclaring the value of session variable 'x' here
$_SESSION['x'] = $_SESSION['x']+1;
This is why its appearing 1 greater than its initial value.
it is due to the code itself
if(isset($_SESSION['x'])) //It is set
$_SESSION['x'] = $_SESSION['x']+1; //Add 1 to the value
echo $_SESSION['x']."<br>"; return value with +1
Solution
The reason the output is different is the order you echo and update
//Echo
//Update Value
//Echo again
Simple solution would be to move this
if (isset($_GET['save']))
{
if(isset($_SESSION['x']))
$_SESSION['x'] = $_SESSION['x']+1;
echo $_SESSION['x']."<br>";
}
else
echo "no submit";
to above this
if(!isset($_SESSION['x']))
$_SESSION['x']=1;
echo "X=". $_SESSION['x'];
Also note set the method and the action in the form to make sure it calls itself
<form method="GET" action="[url to itself]">
<input type="submit" name="save" value="save" />
</form>
Do it like this :
<html><body>
<?php session_start();
if(!isset($_SESSION['x']))
$_SESSION['x']=1;
echo "X=". $_SESSION['x'];
?>
<form method="GET" action="">
<input type="submit" name="save" value="save" />
</form>
<?php
if (isset($_GET['save']))
{
if(isset($_SESSION['x']))
echo $_SESSION['x']."<br>";
}
else
echo "no submit";
?>
</body></html>
this way the code prints out the same value after submit as it did before.
Either way you try if you print value and change after or change value and print after, when page reloads it will change value. you could add another button called increment and add the following code inside the php :
if (isset($_GET['inc']))
{
if(isset($_SESSION['x']))
$_SESSION['x'] = $_SESSION['x']+1;
}
and this one inside the form:
<input type="submit" name="inc" value="inc" />
this way youre variable increment when you press the inc button

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