[RESOLVED] form reset->POST value to radio btn input FAILS

kristo5747

Greetings!

PHP noob here. You've been warned...😃

I'm coding a page form and to prevent its fields to be reset, I have to echo the POST values back into their respective form fields.

It is working well for text inputs but I am having problem with four radio button inputs. Echo-ing the POST values back does not work: the respective form fields are always reset, blanked out...no matter what!!

This is what I wrote...

... 
<td><fieldset> <legend>Frequency: </legend>
<input type="radio" id="rad0" tabindex="8" name="Frequency" value='<?php echo $_POST['Frequency'];?>'>One Time<br>
<input type="radio" id="rad1" tabindex="9" name="Frequency" value='<?php echo $_POST['Frequency'];?>'>Daily<br>
<input type="radio" id="rad2" tabindex="10" name="Frequency" value='<?php echo $_POST['Frequency'];?>'>Weekly<br>
<input type="radio" id="rad3" tabindex="11" name="Frequency" value='<?php echo $_POST['Frequency'];?>'>Monthly<br>
<input type="radio" id="rad4" tabindex="12" name="Frequency" value='<?php echo $_POST['Frequency'];?>'>Ongoing<br>
</fieldset></td>
...

What I am doing wrong?? Can someone please tell me?!

bradgrafelman

It should make sense to you that it's not working; you're giving all 5 radio buttons the same value, meaning you'd have no idea which one was selected when the value is submitted.

Leave their values alone, and instead, echo out checked="checked" for the one radio button that was checked before submission. To determine that, just use an if() statement to see if the $_POST['Frequency'] matches the value of each radio button.

kristo5747

bradgrafelman;10948890 wrote:
It should make sense to you that it's not working; you're giving all 5 radio buttons the same value, meaning you'd have no idea which one was selected when the value is submitted.

Leave their values alone, and instead, echo out checked="checked" for the one radio button that was checked before submission. To determine that, just use an if() statement to see if the $_POST['Frequency'] matches the value of each radio button.

Thanks for your reply. It is confusing me a bit though.

How can echo-ing out checked="checked" back to the respective form fields preserve the values that were initially selected?

Can you please elaborate?

bradgrafelman

Erm.. not sure how to elaborate other than.. because that's how the HTML was designed?

EDIT: Just to be clear... you only echo that into one of the radio elements - whichever one the user selected.

kristo5747

Okay...here's what I did in my page...but it does not work. Same problem.

...<td><fieldset> <legend>Frequency: </legend>
<input type="radio" id="rad0" tabindex="8" name="Frequency" value="One Time" <?php echo $ontime_status; ?>>One Time<br>
<input type="radio" id="rad1" tabindex="9" name="Frequency" value="Daily" <?php echo $dly_status; ?>>Daily<br>
<input type="radio" id="rad2" tabindex="10" name="Frequency" value="Weekly" <?php echo $wky_status; ?>>Weekly<br>
<input type="radio" id="rad3" tabindex="11" name="Frequency" value="Monthly" <?php echo $mthly_status; ?>>Monthly<br>
<input type="radio" id="rad4" tabindex="12" name="Frequency" value="Ongoing" <?php echo $ongoing_status; ?>>Ongoing<br>
</fieldset></td>...

... and my code...

...if (isset($_POST['Frequency'])) {
        $selected_radio = $_POST['Frequency'];        

        if($selected_radio == 'One Time') {
            $ontime_status = 'checked';
        } elseif($selected_radio == 'Daily') {
            $dly_status = 'checked';
        } elseif($selected_radio == 'Weekly') {
            $wky_status = 'checked';
        } elseif($selected_radio == 'Monthly') {
            $mthly_status = 'checked';
        } elseif($selected_radio == 'Ongoing') {
            $ongoing_status = 'checked';
        }
    }...

Any advice!?

Weedpacket

What does the HTML received by the browser look like? (Incidentally, modern practice recommends you use 'checked="checked"', rather than just 'checked'.)

Do you initialise those variables all to empty strings prior to testing $_POST['Frequency']?

bradgrafelman

EDIT: I really need to stop second guessing myself today.

Answer Weedpacket's questions and ignore this post. :p

kristo5747

Thanks to Google...I got my solution:

<td><fieldset> <legend>Frequency: </legend>
<input type="radio" id="rad0" tabindex="8" name="Frequency" value="One Time" <?php echo ($_POST['Frequency']=="One Time")?"CHECKED":""; ?>>One Time<br>
<input type="radio" id="rad1" tabindex="9" name="Frequency" value="Daily" <?php echo ($_POST['Frequency']=="Daily")?"CHECKED":""; ?>>Daily<br>
<input type="radio" id="rad2" tabindex="10" name="Frequency" value="Weekly" <?php echo ($_POST['Frequency']=="Weekly")?"CHECKED":""; ?>>Weekly<br>
<input type="radio" id="rad3" tabindex="11" name="Frequency" value="Monthly" <?php echo ($_POST['Frequency']=="Monthly")?"CHECKED":""; ?>>Monthly<br>
<input type="radio" id="rad4" tabindex="12" name="Frequency" value="Ongoing" <?php echo ($_POST['Frequency']=="Ongoing")?"CHECKED":""; ?>>Ongoing<br>
</fieldset></td>

Looking at the HTML code, CHECKED shows up right next to the radio button I select. Did not even have to init my variables all to empty strings

laserlight

kristo5747 wrote:
Thanks to Google...I got my solution:
(...)
Looking at the HTML code, CHECKED shows up right next to the radio button I select. Did not even have to init my variables all to empty strings

Yes, but it may be useful to try and follow the Don't Repeat Yourself (DRY) principle. In this case, you are repeating yourself by hard coding the text like "One Time" twice. You might do something like this instead:

<td><fieldset>  <legend>Frequency: </legend>
<?php
$radio_values = array('One Time', 'Daily', 'Weekly', 'Monthly', 'Ongoing');
$frequency = isset($_POST['Frequency']) ? $_POST['Frequency'] : '';
for ($i = 0; $i < count($radio_values); ++$i) {
    printf('<input type="radio" id="rad%d" tabindex="%d" name="Frequency" value="One Time"%s>%s<br>',
        $i,
        $i + 8,
        ($frequency == $radio_values[$i]) ? 'checked' : '',
        htmlspecialchars($radio_values[$i]));
}
?>
</fieldset></td>

kristo5747

Wow....kudos to you and your coding skills. 🆒

.........I am light-years away from getting there.

kristo5747

laserlight;10948907 wrote:

...You might do something like this instead:

<td><fieldset>  <legend>Frequency: </legend>
<?php
$radio_values = array('One Time', 'Daily', 'Weekly', 'Monthly', 'Ongoing');
$frequency = isset($_POST['Frequency']) ? $_POST['Frequency'] : '';
for ($i = 0; $i < count($radio_values); ++$i) {
    printf('<input type="radio" id="rad%d" tabindex="%d" name="Frequency" value="One Time"%s>%s<br>',
        $i,
        $i + 8,
        ($frequency == $radio_values[$i]) ? 'checked' : '',
        htmlspecialchars($radio_values[$i]));
}
?>
</fieldset></td>

Would your example work with checkboxes too? I understand that a group of checkboxes is in fact an array of values, correct?

bradgrafelman

kristo5747 wrote:
I understand that a group of checkboxes is in fact an array of values, correct?

A group of checkboxes is just that - a group of checkboxes. If you give them all the same name with '[]' on the end, then they can be submitted and PHP will process them of arrays, yes.

As for your question, laserlight's example simply loops through an array of values and outputs some HTML. In that sense, the example would "work with" anything that has patterns of repeated code, checkboxes included.