From 186e0c8561cc908c2974ded4a42c0e8e65cbad79 Mon Sep 17 00:00:00 2001
From: d-buchmann <buchmann@ticmed.de>
Date: Tue, 1 Jul 2025 14:36:31 +0200
Subject: [PATCH] Update AbstractParameter.php

Make lazy null conditionals explicit.
Try to handle LaTeX special chars gracefully.
Fixes #958
---
 src/Entity/Parameters/AbstractParameter.php | 28 ++++++++++++++++-----
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/src/Entity/Parameters/AbstractParameter.php b/src/Entity/Parameters/AbstractParameter.php
index edcedc3e..eee0a030 100644
--- a/src/Entity/Parameters/AbstractParameter.php
+++ b/src/Entity/Parameters/AbstractParameter.php
@@ -217,7 +217,7 @@ abstract class AbstractParameter extends AbstractNamedDBElement implements Uniqu
 
         $str = '';
         $bracket_opened = false;
-        if ($this->value_typical) {
+        if ($this->value_typical !== null) {
             $str .= $this->getValueTypicalWithUnit($latex_formatted);
             if ($this->value_min || $this->value_max) {
                 $bracket_opened = true;
@@ -225,11 +225,11 @@ abstract class AbstractParameter extends AbstractNamedDBElement implements Uniqu
             }
         }
 
-        if ($this->value_max && $this->value_min) {
+        if ($this->value_max !== null && $this->value_min !== null) {
             $str .= $this->getValueMinWithUnit($latex_formatted).' ... '.$this->getValueMaxWithUnit($latex_formatted);
-        } elseif ($this->value_max) {
+        } elseif ($this->value_max !== null) {
             $str .= 'max. '.$this->getValueMaxWithUnit($latex_formatted);
-        } elseif ($this->value_min) {
+        } elseif ($this->value_min !== null) {
             $str .= 'min. '.$this->getValueMinWithUnit($latex_formatted);
         }
 
@@ -449,7 +449,15 @@ abstract class AbstractParameter extends AbstractNamedDBElement implements Uniqu
             if (!$with_latex) {
                 $unit = $this->unit;
             } else {
-                $unit = '$\mathrm{'.$this->unit.'}$';
+                // if chars occur that will mess up the latex formatting, display them plain, regardless of the desired output
+                if (str_contains($this->unit, '~') || str_contains($this->unit, '^') || str_contains($this->unit, '\\'))
+                {
+                    $unit = $this->unit;
+                }
+                else // otherwise, style the chars with latex, but escape latex special chars
+                {
+                    $unit = '$\mathrm{'.$this->latexEscape($this->unit).'}$';
+                }
             }
 
             return $str.' '.$unit;
@@ -457,7 +465,15 @@ abstract class AbstractParameter extends AbstractNamedDBElement implements Uniqu
 
         return $str;
     }
-
+    
+    /**
+     * Return a latex escaped string
+     */
+    protected function latexEscape(string $latex): string
+    {
+        return preg_replace('/(\&|\%|\$|\#|\_|\{|\})/', "\\\\$1", $latex);
+    }
+    
     /**
      * Returns the class of the element that is allowed to be associated with this attachment.
      * @return string