From 3efba18ad48ebaab3c33204d8d2df3887e3b4c0c Mon Sep 17 00:00:00 2001
From: bgbsww <bgbsww@gmail.com>
Date: Wed, 17 Jul 2024 21:07:02 -0400
Subject: [PATCH] Expand reader getAttribute calls to accept a default value

---
 src/Base/Reader.cpp | 47 +++++++++++++++------------------------------
 src/Base/Reader.h   | 24 ++++++++++++++++-------
 2 files changed, 32 insertions(+), 39 deletions(-)

diff --git a/src/Base/Reader.cpp b/src/Base/Reader.cpp
index 8640c8eef3..17894c2bb2 100644
--- a/src/Base/Reader.cpp
+++ b/src/Base/Reader.cpp
@@ -109,52 +109,35 @@ unsigned int Base::XMLReader::getAttributeCount() const
     return static_cast<unsigned int>(AttrMap.size());
 }
 
-long Base::XMLReader::getAttributeAsInteger(const char* AttrName) const
+long Base::XMLReader::getAttributeAsInteger(const char* AttrName, const char* defaultValue) const
 {
-    AttrMapType::const_iterator pos = AttrMap.find(AttrName);
-
-    if (pos != AttrMap.end()) {
-        return atol(pos->second.c_str());
-    }
-    // wrong name, use hasAttribute if not sure!
-    std::ostringstream msg;
-    msg << "XML Attribute: \"" << AttrName << "\" not found";
-    throw Base::XMLAttributeError(msg.str());
+    const int base = 10;
+    return strtol(getAttribute(AttrName, defaultValue), nullptr, base);
 }
 
-unsigned long Base::XMLReader::getAttributeAsUnsigned(const char* AttrName) const
+unsigned long Base::XMLReader::getAttributeAsUnsigned(const char* AttrName,
+                                                      const char* defaultValue) const
 {
-    AttrMapType::const_iterator pos = AttrMap.find(AttrName);
-
-    if (pos != AttrMap.end()) {
-        return strtoul(pos->second.c_str(), nullptr, 10);
-    }
-    // wrong name, use hasAttribute if not sure!
-    std::ostringstream msg;
-    msg << "XML Attribute: \"" << AttrName << "\" not found";
-    throw Base::XMLAttributeError(msg.str());
+    const int base = 10;
+    return strtoul(getAttribute(AttrName, defaultValue), nullptr, base);
 }
 
-double Base::XMLReader::getAttributeAsFloat(const char* AttrName) const
+double Base::XMLReader::getAttributeAsFloat(const char* AttrName, const char* defaultValue) const
 {
-    AttrMapType::const_iterator pos = AttrMap.find(AttrName);
-
-    if (pos != AttrMap.end()) {
-        return atof(pos->second.c_str());
-    }
-    // wrong name, use hasAttribute if not sure!
-    std::ostringstream msg;
-    msg << "XML Attribute: \"" << AttrName << "\" not found";
-    throw Base::XMLAttributeError(msg.str());
+    return strtod(getAttribute(AttrName, defaultValue), nullptr);
 }
 
-const char* Base::XMLReader::getAttribute(const char* AttrName) const
+const char* Base::XMLReader::getAttribute(const char* AttrName,            // NOLINT
+                                          const char* defaultValue) const  // NOLINT
 {
-    AttrMapType::const_iterator pos = AttrMap.find(AttrName);
+    auto pos = AttrMap.find(AttrName);
 
     if (pos != AttrMap.end()) {
         return pos->second.c_str();
     }
+    if (defaultValue) {
+        return defaultValue;
+    }
     // wrong name, use hasAttribute if not sure!
     std::ostringstream msg;
     msg << "XML Attribute: \"" << AttrName << "\" not found";
diff --git a/src/Base/Reader.h b/src/Base/Reader.h
index 045edbd6ed..23cb2bf962 100644
--- a/src/Base/Reader.h
+++ b/src/Base/Reader.h
@@ -217,13 +217,23 @@ public:
     unsigned int getAttributeCount() const;
     /// check if the read element has a special attribute
     bool hasAttribute(const char* AttrName) const;
-    /// return the named attribute as an integer (does type checking)
-    long getAttributeAsInteger(const char* AttrName) const;
-    unsigned long getAttributeAsUnsigned(const char* AttrName) const;
-    /// return the named attribute as a double floating point (does type checking)
-    double getAttributeAsFloat(const char* AttrName) const;
-    /// return the named attribute as a double floating point (does type checking)
-    const char* getAttribute(const char* AttrName) const;
+
+    /// return the named attribute as an integer (does type checking); if missing return
+    /// defaultValue
+    long getAttributeAsInteger(const char* AttrName, const char* defaultValue = nullptr) const;
+
+    /// return the named attribute as unsigned integer (does type checking); if missing return
+    /// defaultValue
+    unsigned long getAttributeAsUnsigned(const char* AttrName,
+                                         const char* defaultValue = nullptr) const;
+
+    /// return the named attribute as a double floating point (does type checking); if missing
+    /// return defaultValue
+    double getAttributeAsFloat(const char* AttrName, const char* defaultValue = nullptr) const;
+
+    /// return the named attribute as a double floating point (does type checking); if missing
+    /// return defaultValue
+    const char* getAttribute(const char* AttrName, const char* defaultValue = nullptr) const;
     //@}
 
     /** @name additional file reading */