CODEWITHSUNDEEP
php
Vaheed01
Vaheed01

Reputation: 1057

show empty string if property not exist

In the lower versions of php I used to use the following code to show object property in the page :

  <input type=text value='<?php echo $obj->title ;?>'>

In the edit mode $obj was an object fetched from database and user could see the already existed value, and for insert mode there was no $obj because there was no $_GET["obj_id"] and $obj wasn't defined so the input field was shown empty ,

In the new versions php stops the insert pages because $obj isn't defined or has no property named title , So I should use something like this :

<input type=text value='<?php echo isset($obj)?$obj->title:"" ;?>'>

Now what I want to do is to make this some shorten, I created a function like the following but it doesn't seem to work and keeps showing the error,

function showprop($obj,$prop)
{
if( isset($obj) )
 echo $obj->{$prop};
else
 echo "";
}

<input type=text value='<?php showprop($obj,"title");?>'>

Any suggestion to make this work without getting notice? Thanks in advance

Upvotes: 0

Views: 203

Answers (2)

Damian Dziaduch
Damian Dziaduch

Reputation: 2127

It won't work because the $obj is not defined. But you can pass the variable of the name to the function and check whether the global variable is defined in that function - but this is ugly:

function showprop($obj,$prop)
{
    if( isset($_GLOBALS[$obj]) )
        echo $_GLOBALS[$obj]->{$prop};
    else
        echo "";
}

<input type=text value='<?php showprop('obj',"title");?>'>

Upvotes: 1

deceze
deceze

Reputation: 522135

A function is not going to work, since PHP will try to resolve $obj before passing its value into the function, so you're left with the same problem.

Use the null coalescing operator instead (available from PHP 7):

<?= $obj->title ?? '' ?>

Upvotes: 4

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