Fix {add $var}content{/add} generates invalid PHP

[maxisoft-git]

Fix for Issue #348

Problem

When using {add \$var}content{/add} without explicit value assignment, the generated PHP code was invalid:

$var = if(!isset($var)) {
    ob_get_clean();
}

This caused a parse error: "syntax error, unexpected token 'if'".

Solution

Changed setClose in Compiler.php to wrap the ENTIRE assignment in the IF condition, not just the value part:

if(!isset($var)) {
    $var = ob_get_clean();
} else {
    ob_end_clean();
}

This correctly:

• Captures content into variable if variable is NOT set
• Discards buffer without outputting if variable IS already set

Tests Added

• {add $v}Hello{/add} Result: {$v} - basic capture
• {add $v}Value: {$x}{/add} - capture with variable interpolation
• {set $v = "first"}{add $v}second{/add} - verify {add} does NOT overwrite existing variable

Fixes

Fixes #348