Call to a member function format() on boolean - php

Question

I want to find the difference between two dates and I have used date_diff for the same. When format function is applied on date_diff object it returns an error.
Call to a member function format() on boolean
$field_value is fetched from the database and it's format is dd/mm/YYYY. When I hard-code the values for $field_value and $indexing_value the following code works.
Everything is running fine till line number 8. I have tried outputting the value of
$diff->format("%R%a")
and it is returning exact value but the code gives error near the if statement.
$date = new DateTime();
$current_date = $date->format('d/m/Y');
$indexing_value = str_replace("/", "-", $field_value);
$current_value = str_replace("/", "-", $current_date);
$indexing_value = date_create($indexing_value);
$current_value = date_create($current_value);
$diff = date_diff($indexing_value, $current_value);
if ($diff->format("%R%a") < 0) {
echo "1";
} else {
echo "2";
}
Please let me know what is wrong with the above code.

Answer 1

add condition to check whether you got the diff or not, as it returns false if there is error . Check manual for the same
$diff = date_diff($indexing_value, $current_value);
if ($diff) {
if ($diff->format("%R%a") < 0) {
echo "1";
}else{
echo "2";
}
}
You are getting error because for some values the diff is not calculated and have value False in $diff

Answer 2

Please let me know what is wrong with the above code.
There are several issues with the code:
You don't check the values returned by date_create(); it returns FALSE on error.
What's the point of formatting $date then creating $current_value back from the resulting string? If you don't care about the time components and need to use only the date part of a DateTime object you can use its setTime() method to set the time components to 0.
What's the point of using str_replace() to manipulate the text representation of a date when you know its format? DateTime::createFromFormat() can be used to parse the string into a DateTime object.
There is no need to compute the difference of the two dates and the format it and compare the value to 0. The DateTime objects can be compared directly.
All in all, all the code you need is:
// Current date & time
$today = new DateTime();
// Ignore the time (change $today to "today at midnight")
$today->setTime(0, 0, 0);
// Parse the value retrieved from the database
$field = DateTime::createFromFormat('d/m/Y', $field_value);
// We don't care about the time components of $field either (because the time
// is not provided in the input string it is created using the current time)
$field->setTime(0, 0, 0);
// Directly compare the DateTime objects to see which date is before the other
if ($field < $today) {
echo "1";
} else {
echo "2";
}