| Re: echo other way to output a constant? [message #169500 is a reply to message #169486] |
Wed, 15 September 2010 15:25   |
Peter H. Coffin
Messages: 245
Registered: September 2010
Karma:
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Senior Member |
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On Tue, 14 Sep 2010 20:52:31 -0500, MikeB wrote:
> Peter H. Coffin wrote:
>> On Tue, 14 Sep 2010 17:12:38 -0500, MikeB wrote:
>>> Say I have the following code:
>>>
>>> <?php
>>>
>>>
>>> define('MAX_FILE_SIZE', 300);
>>>
>>> echo<<<_END
>>> <html><head><title>PHP Form Upload</title></head><body>
>>> <form method='post' action='UploadFile2.php' enctype='multipart/form-data'>
>>> <!-- MAX_FILE_SIZE must precede the file input field -->
>>> <input type="hidden" name="MAX_FILE_SIZE" value="" />
>>> Select a JPG, GIF, PNG or TIF File:
>>> <input type='file' name='filename' size='60' />
>>> <br/><input type='submit' value='Upload' /></form>
>>> _END;
>>>
>>> echo "</body></html>";
>>> ?>
>>>
>>> How can I get PHP to place the value of the constant MAX_FILE_SIZE in
>>> the value attribute for the hidden field MAX_FILE_SIZE?
>>>
>>> Since it does not start with a $-sign it is not interpreted as a
>>> variable. I tried putting it in curly braces {}, which sometimes work,
>>> but that didn't do the trick either.
>>>
>>> I was hoping that print_r() would do it, but I could not get PHP to
>>> interpret that either.
>>>
>>> So any way or do I have to a) put the constant in a variable or b) echo
>>> each line individually so that I can do concatenation of the output lines?
>>
>> PHP puts responses to forms sent using method post into a special array
>> called "_POST". So, to get at the contents of an input control called
>> "MAX_FILE_SIZE", you use the variable $_POST['MAX_FILE_SIZE']. There is
>> some trickiness with input types that can return multiple values, but we
>> can get to that once you've gotten the above bits working and are
>> comfortable with them.
>>
> Perhaps I expressed myself poorly.
Or perhaps I read poorly.
> I want PHP to send html to the browser.
>
> It should look like this:
>
> <input type="hidden" name="MAX_FILE_SIZE" value="300" />
>
> This is as part of an echo <<<_END statement.
>
> The number 300 in the above instance is a constant in my PHP code
> defined as:
>
> define('MAX_FILE_SIZE', 300);
>
> If I try to put the following in my program, the literal MAX_FILE_SIZE
> appears in the html:
>
> echo <<<_END
> <input type="hidden" name="MAX_FILE_SIZE" value="MAX_FILE_SIZE" />
> _END
>
> if I do this, I get what I want:
>
> $mfs = MAX_FILE_SIZE;
> echo <<<_END
> <input type="hidden" name="MAX_FILE_SIZE" value="$mfs" />
> _END
>
> So are you saying that an alternate method is to initialize the
> MAX_FILE_SIZE element in the _POST array and do it that way?
>
> Thanks.
No, but I don't think you can do variable or constant expansion inside a
heredoc, the thing with the <<< operation. You can terminate it early,
before the part that you want to contain the variable, print a bit that
includes the variable expansion, then do more heredoc dumping. Thusly:
<?php
$MAX_FILE_SIZE=300;
echo<<<_END
<html><head><title>PHP Form Upload</title></head><body>
<form method='post' action='UploadFile2.php'
enctype='multipart/form-data'>
<!-- MAX_FILE_SIZE must precede the file input field -->
_END;
print "<input type='hidden' name='$MAX_FILE_SIZE' value='' />";
echo<<<_END
Select a JPG, GIF, PNG or TIF File:
<input type='file' name='filename' size='60' />
<br/><input type='submit' value='Upload' /></form>
_END;
echo "</body></html>";
?>
As far as I can remember, heredocs do zero procession on the output
aside from checking for line-ending-followed-by-end-tag. Which means
you can potentially be bitten by line ending problems, character set
problems, etc, etc.
--
_ o
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