PHP isset形式POST值的简写

Question

I am creating a form and am just looking for more efficient ways to do things. What I have so far is:

<p><input type="text" name="transmission" value="" /></p>
<p><input type="text" name="model" value="<?=$model;?>" /></p>

So some of them will have a value already set, and some will be blank. What I want to do is see if the form has been set, and if it has then use $_POST['name'] as the value, if not then use either blank or use the previous variable I have.

<p><input type="text" name="name" value="<?php if isset($_POST['submit'])) { echo $_POST['name']; } else { echo ""; } ?>" /></p>

But there has to be a shorter way to do that.

IF anyone could point me in the direction I would really appreciate it.

Thank you!

Answer 1

You can define variables in beginning of your script before HTML output, for example:

$name = isset($_POST['submit']) ? $_POST['name'] : null;

in your html section you can print $name without worrying it was not defined

<p><input type="text" name="name" value="<?php echo $name ?>" /></p>

Also if $_POST['submit'] does not contain any value you are more likely to receive FALSE statement. To avoid such issues use array_key_exists

Answer 2

Like Nazariy said, you should avoid as much PHP in the template as possible.
In fact, you should have in your template already prepared variables only.

So, in your code have something like this

$FORM = array();
$form_fields = array('name','sex');
foreach($form_fields as $fname) {
  if (isset($_POST[$fname])) {
    $FORM[$fname] = htmlspecialchars($_POST[$fname]);
  } else {
    $FORM[$fname] ='';
  }
}

and then you have smooth and neat template:

<p><input type="text" name="name" value="<?=$FORM['name']?>" /></p>

Answer 3

速记<?=$_POST['name'] ?: ''?>

Answer 4

在没有使用<p>构建表单的原因的情况下，除了删除else之外，没有太多可以做的else 。

<p><input type="text" name="name" value="<?php if isset($_POST['name'])) echo $_POST['name']; ?>" /></p>

Answer 5

I just saw this from wordpress coding standard. although they not encourage for the readability..

isset( $var ) || $var = some_function();

reference here

Answer 6

Use the php error control operator: @.

<?php

   $posted_text = @$_POST['posted_text'];
   echo $posted_text

?>  

If the POST variable is set, it will be echo-ed out. If not, nothing will show up.

Answer 7

You could try this...

$_POST['submit'] ? echo $_POST['name'] : echo '';

I'm using a boolean compare instead of the isset function (see link for table)

http://www.php.net/manual/en/types.comparisons.php

or an other option is...

echo ($_POST['submit'] ? $_POST['name'] : '');

Answer 8

<?= isset($_POST['submit'])? $_POST['name'] : ""; ?>

Is the shortest you'll get it, apart from say <?= $_POST['name']; ?> <?= $_POST['name']; ?> (if submit is not set name should be empty anyway) - you probably need to turn warnings off.

All that being said, this is very very poor practice and opens you up to cross site scripting (XSS) . You should NOT be doing this. Even on an intranet, if an attacker ever owns a computer that has access to it they can use XSS to perform any actions the user can.

From your question and how much distaste you have for this type of echoing on screen I'd suggest you use some form of templating library such as Smarty . This allows your html code to look like this:

<p><input type="text" name="name" value="{name}" /></p>