Extend functions that process SDF files to also accept SDF strings

scenario/src/gazebo/include/scenario/gazebo/utils.h

@@ -111,28 +111,27 @@ namespace scenario::gazebo::utils {
     std::string getSdfString(const std::string& fileName);
 
     /**
-     * Get the name of a model from a SDF file.
+     * Get the name of a model from a SDF file or SDF string.
      *
-     * @note sdformat supports only one model per SDF file.
+     * @note sdformat supports only one model per SDF.
      *
-     * @param fileName An SDF file. It could be either an absolute path
-     *        to the file or the file name if the parent folder is part
-     *        of the ``IGN_GAZEBO_RESOURCE_PATH`` environment variable.
-     * @return The name of the model if the file was found and is valid,
-     *         an empty string otherwise.
+     * @param fileName An SDF file or string. It could be an absolute path to
+     * the file, the file name if the parent folder is part of the
+     * ``IGN_GAZEBO_RESOURCE_PATH`` environment variable, or a SDF string.
+     * @return The name of the model if the SDF is valid, an empty string
+     * otherwise.
      */
     std::string getModelNameFromSdf(const std::string& fileName);
 
     /**
-     * Get the name of a world from a SDF file.
+     * Get the name of a world from a SDF file or SDF string.
+     *
+     * @param fileName An SDF file or string. It could be an absolute path to
+     * the file, the file name if the parent folder is part of the
+     * ``IGN_GAZEBO_RESOURCE_PATH`` environment variable, or a SDF string.
+     * @return The name of the world if the SDF is valid, an empty string
+     * otherwise.
      *
-     * @param fileName An SDF file. It could be either an absolute path
-     *        to the file or the file name if the parent folder is part
-     *        of the ``IGN_GAZEBO_RESOURCE_PATH`` environment variable.
-     * @param worldIndex The index of the world in the SDF file. By
-     *        default it finds the first world.
-     * @return The name of the world if the file was found and is valid,
-     *         an empty string otherwise.
      */
     std::string getWorldNameFromSdf(const std::string& fileName,
                                     const size_t worldIndex = 0);

scenario/src/gazebo/src/utils.cpp

@@ -88,19 +88,20 @@ std::string utils::getSdfString(const std::string& fileName)
 {
     // NOTE: We could use std::filesystem for the following, but compilers
     //       support is still rough even with C++17 enabled :/
-    std::string sdfFileAbsPath;
+    std::string sdfFileAbsPath = fileName;
 
-    if (!ignition::common::isFile(fileName)) {
+    std::shared_ptr<sdf::Root> root;
+
+    if (ignition::common::isFile(fileName)) {
         sdfFileAbsPath = findSdfFile(fileName);
+        root = getSdfRootFromFile(fileName);
     }
-
-    if (sdfFileAbsPath.empty()) {
-        return {};
+    else {
+        root = getSdfRootFromString(sdfFileAbsPath);
     }
 
-    auto root = getSdfRootFromString(sdfFileAbsPath);
-
     if (!root) {
+        sError << "Failed to get SDF string" << std::endl;
         return {};
     }
 
@@ -109,24 +110,30 @@ std::string utils::getSdfString(const std::string& fileName)
 
 std::string utils::getModelNameFromSdf(const std::string& fileName)
 {
-    std::string absFileName = findSdfFile(fileName);
+    // NOTE: We could use std::filesystem for the following, but compilers
+    //       support is still rough even with C++17 enabled :/
+    std::string sdfFileAbsPath = fileName;
 
-    if (absFileName.empty()) {
-        sError << "Failed to find file " << fileName << std::endl;
-        return {};
-    }
+    std::shared_ptr<sdf::Root> root;
 
-    const auto root = utils::getSdfRootFromFile(absFileName);
+    if (ignition::common::isFile(fileName)) {
+        sdfFileAbsPath = findSdfFile(fileName);
+        root = getSdfRootFromFile(fileName);
+    }
+    else {
+        root = getSdfRootFromString(sdfFileAbsPath);
+    }
 
     if (!root) {
+        sError << "Failed to get model name from SDF" << std::endl;
         return {};
     }
 
-    if (const auto model = root->Model()) {
+    if (const auto& model = root->Model()) {
         return model->Name();
     }
 
-    sError << "No model found in file " << fileName << std::endl;
+    sError << "No model found in SDF" << std::endl;
     return {};
 }