Can anyone help me fix this php string mess?

echo '<nav ><a href="' . $route . '" '.($_SERVER['REQUEST_URI'] == '/' . $route) ? 'style="color:' . $currentPathColor . '"' : '' . '>' . $route . '</a></nav>';

This is whats supposed to do(this works):

  if ($_SERVER['REQUEST_URI'] == '/' . $route) {
    echo '<nav ><a href="' . $route . '" style="color:' . $currentPathColor . '">' . $route . '</a></nav>';
} else {
    echo '<nav ><a href="' . $route . '">' . $route . '</a></nav>';
}

Just practicing PHP for the purpose of knowing something about it, thanks in advance!

CodePudding user response：

As PHP is a template engine, you can make use of it and maintain readability.

$style = ($_SERVER['REQUEST_URI'] === "/$route") ? "style='color:$currentPathColor'" : '';

echo <<<_HTML
<nav ><a href="$route" $style>$route</a></nav>
_HTML;

CodePudding user response：

I can understand wanting to reduce repetition of code, and as such I would suggest putting the common html in two separate parts with an if in the middle. This achieves the same as you are trying to get but with (IMHO) a more maintainable structure...

echo '<nav ><a href="' . $route;
if ($_SERVER['REQUEST_URI'] == '/' . $route) {
    echo '" style="color:' . $currentPathColor;
} 
echo  '">' . $route . '</a></nav>';

( I have not tested this, so can't 100% guarantee the quotes are correct, but I hope you get the idea.)

CodePudding user response：

Others have given some reasonable alternative styles, but to address the immediate problem, your issue is one of operator precedence.

In order of precedence, you have:

1. A parenthesised expression
2. The . concatenation operator
3. The ternary ?: operator

So PHP evaluates things a bit like this:

// Parentheses
$boolean = $_SERVER['REQUEST_URI'] == '/' . $route;
// Concatenation
$string_1 = '<nav ><a href="' . $route . '" '. $boolean;
$string_2 = 'style="color:' . $currentPathColor . '"';
$string_3 = '' . '>' . $route . '</a></nav>';
// Ternary
$chosen_string = $string_1 ? $string_2 : $string_3;
// echo
echo $chosen_string;

But what you wanted was this:

// String sections
$prefix = '<nav ><a href="' . $route . '" ';
$suffix_a = 'style="color:' . $currentPathColor . '"';
$suffix_b = '' . '>' . $route . '</a></nav>';
// Condition
$condition = $_SERVER['REQUEST_URI'] == '/' . $route;
// Ternary
$chosen_suffix = $condition ? $suffix_a : $suffix_b;
// Combine
$string = $prefix . $chosen_suffix;
// echo
echo $string;

So as well as parentheses around the condition, you want parentheses around the whole "suffix" section, so that that gets evaluated first:

echo
    '<nav ><a href="' . $route . '" '
    .
    (
        ( $_SERVER['REQUEST_URI'] == '/' . $route )
        ?
        'style="color:' . $currentPathColor . '"'
        :
        '' . '>' . $route . '</a></nav>'
    );

Since this kind of mistake is so easy to make, and the result easy to misinterpret, it's generally a good idea to simply avoid complex expressions like this, and introduce intermediate variables, use if statements, and so on.