Form submission doesn't work - PHP

Question

I'm working on a form validation and I'm currently doing some debugging on my code. I'll insert the necessary code snippets below:

Form code:

echo '<h1> Seismic Recording </h1>
<div>
<form action="validate2.php" method="POST">';

echo "Latitude: <input type='text' name='latitude'>";
echo "Longitude: <input type='text' name='longitude'required>";
echo 'Wave Type: <select id="wave_type" name="wave_type" required>
        <option selected value="s">S</option>
        <option value="p">P</option>
        <option value="surface_wave">Surface Wave</option>
        </select>';
echo "Wave Value: <input type='text' name='wave_value' required>";
echo 'Upload CSV File: <input type="file" name="file">';
echo " <input type='submit' name='submit' value='submit'>";
echo "</form>
</div> ";

Validation code:

echo "w";

if (isset($_POST['submit'])) {
    echo "t";
    $latitude = $_POST['latitude'];
    if ($latitude  == NULL) {
        echo "Please insert a latitude . <br>";
        $error = $error + 1;
    }
}

echo "q";

The form validations that I've put within the if statement doesn't work. I tried debugging the code by inserting the 'echo "q"' and 'echo "w"' to see where the problem lies. Those statements work (they output the characters). But the 'echo "t"' within the if statement doesn't work. Why is that so?

Result of var_dump($_POST):

array(5) { ["latitude"]=> string(0) "" ["longitude"]=> string(1) "g" ["wave_type"]=> string(1) "s" ["wave_value"]=> string(1) "g" ["file"]=> string(0) "" }

My issue isn't so much in getting the latitude to validate but why doesn't the 'echo t' work?

show your full html code, r u using ??? because as per your debugging, `if (isset($_POST['submit'])) {` this not working. — devpro, Oct 07 '16 at 15:06
And: What did you enter into the form on your test? Because if `$_POST['submit']` was set, then maybe `$_POST['latitude']` is stil empty — JustOnUnderMillions, Oct 07 '16 at 15:08
`$latitude` can never be equal to `NULL`, instead use this `if` condition: `if(!isset($latitude) || empty($latitude)){ ...` — Rajdeep Paul, Oct 07 '16 at 15:09
Show your real code not the half pasted stuff here, show your test data, show dump of request ;) What should we guess from that, what you have pasted?? — JustOnUnderMillions, Oct 07 '16 at 15:11
If this is a legacy project, good luck, else, I recommend using a framework. Why work so hard? http://webdeveloper.gdemolished.com/stop-building-shitty-php-web-applications/ — Halfstop, Oct 07 '16 at 15:13
@jszobody I did that. It shows latitude as being empty. But my question is apart from the latitude, why doesn't the 'echo "t"' prints? — Danielle, Oct 07 '16 at 15:15
@JustOnUnderMillions Please see edits. I placed values in everything except latitude. — Danielle, Oct 07 '16 at 15:16
I tested the `form` as it is here, and it works. Do the `var_dump($_POST);` test. — JustOnUnderMillions, Oct 07 '16 at 15:21
working fine on my side. can u check the action? `validate2.php` is it right? i am using same file for form and php code. and its working fine — devpro, Oct 07 '16 at 15:21
Test it in a single file with `action=""` and `var_dump($_POST);` at the end — JustOnUnderMillions, Oct 07 '16 at 15:22
@Hackerman Please see updated edit with the results of var_dump($_POST) — Danielle, Oct 07 '16 at 15:25
@JustOnUnderMillions Please see updated edit with the results of var_dump($_POST) — Danielle, Oct 07 '16 at 15:25
change `if ($latitude == NULL) {` with `if (empty($latitude)) {` — devpro, Oct 07 '16 at 15:25
@devpro Yes, the action is okay. Did your "echo t" statement work? — Danielle, Oct 07 '16 at 15:26
yes, its working. also try with `if ($latitude == NULL) { with if (empty($latitude)) {` — devpro, Oct 07 '16 at 15:26
your latidute is equal to `""` empty, you can't check it with NULL — devpro, Oct 07 '16 at 15:27
Did you notice that `submit` is missing in your output of `var_dump($_POST)` ?? — JustOnUnderMillions, Oct 07 '16 at 15:34
Seems a server or PHP konfiugration bug or so. Here all works fine. So it isnt the code itself. some other magical stuff on your server. — JustOnUnderMillions, Oct 07 '16 at 15:36
@JustOnUnderMillions Thanks, so there's no way for me to fix it? — Danielle, Oct 07 '16 at 15:39
Not in PHP currently. Test the code on another server. Or just test for `["latitude"]` is set in the first place, you dont need to check for `submit`, maybe take a hidden input and take that for check. ..... cant tell more, not enuff infos — JustOnUnderMillions, Oct 07 '16 at 15:41
Did you 'click' the button or do you hit 'enter' ??--- foragt that :) imout — JustOnUnderMillions, Oct 07 '16 at 15:46
@JustOnUnderMillions It doesn't work when I hit enter but it does work when i click the button. Thanks. Why is there a difference? — Danielle, Oct 07 '16 at 15:48

score 0 · Answer 1 · answered Oct 07 '16 at 15:28

0

Why check for a 'submit' post variable when you're working with latitude?

if(isset($_POST['latitude']))
{
     echo "t";
     $latitude=$_POST['latitude'];
}
else
{
     echo "Please insert a latitude . <br>";
     $error = $error + 1;
}

Also there is no need for a name on the submit button

<input type="submit" value="Submit">

answered Oct 07 '16 at 15:28

Stephan

531
3
16

Because I'll be adding more validations within the if statement. My main question isn't about the validation of latitude but why doesn't 'echo t' work? – Danielle Oct 07 '16 at 15:34
Previous comment says all, in your post dump there is no submit post variable, that's why I wouldn't check for it. You have latitude, longitude, wave_type, wave_value, file. Just do your if isset statement on variables that actually get set. – Stephan Oct 07 '16 at 18:37

Jay Prakash · Answer 2 · 2016-10-28T13:28:18.183

<!--form code start-->
<?php
if(isset($_REQUEST['req']))
{
    echo "Please enter any input";
}
?>
<form action="validate2.php" method="POST">
    Latitude: <input type='text' name='latitude'>
    <input type='submit' name='submit' value='submit'>
</form>

<!--validate2.php code start-->
<?php
if (isset($_POST['submit']))
{
    $latitude = $_POST['latitude'];
    if ($latitude  == NULL)
    {   
        header("Location:frm.php?req=error");
    }
    else
    {
        echo "Your input Text is: ".$latitude;      
    }
}
?>

score 0 · Answer 3 · answered Oct 07 '16 at 16:00

You just have your form rendering messed up, this works:

echo "<h1> Seismic Recording </h1>";
echo "<div>";
echo "<form action='' method='POST'>";

echo "Latitude: <input type='text' name='latitude'>";
echo "Longitude: <input type='text' name='longitude'd>";
echo 'Wave Type: <select id="wave_type" name="wave_type">';
echo '<option selected value="s">S</option>';
  echo '<option value="p">P</option>';
  echo '<option value="surface_wave">Surface Wave</option>';
echo "</select>";
echo "Wave Value: <input type='text' name='wave_value' d>";
echo 'Upload CSV File: <input type="file" name="file">';
echo "<input type='submit' name='submit' value='submit'>";
echo "</form>";
echo "</div>";

if(isset($_POST)){
  if(isset($_POST['submit'])){
   echo "Submit is alive!!";
  }
}

In order to avoid this kind of issues, remember that you can just write plain html, on this way:

<?php
  //Mi php code blablabla
?>
/* My html code */
<h1>Wonderful day, isn't it?<h1>

<?php
  //Another php tasks and etc
?>

score 0 · Answer 4 · answered Oct 28 '16 at 13:31

<!--Second Method--> 
<!--form code start-->
<form action="validate2.php" method="POST">
    Latitude: <input type='text' name='latitude'>
    <input type='submit' name='submit' value='submit'>
</form>

<!--validate2.php code start-->
<?php
if (isset($_POST['submit']))
{
    $latitude = $_POST['latitude'];
    if ($latitude  == NULL)
    {   
        echo '<script>alert("Please enter any input");
        window.location.href="frm.php";</script>';
    }
    else
    {
        echo "Your input Text is: ".$latitude;      
    }
}
?>

score 0 · Answer 5 · answered Oct 28 '16 at 13:32

0

Try this:-

$curl_connection = 
  curl_init('http://www.domainname.com/target_url.php');

link:-http://www.html-form-guide.com/php-form/php-form-submit.html

answered Oct 28 '16 at 13:32

Razia sultana

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Form submission doesn't work - PHP

5 Answers5