libcore|PackageLoader: Load required packages automatically

The "requires" array specifies all the packages that must be loaded before a package can be successfully loaded.
skyjake · Apr 3, 2016 · 5ac44ce · 5ac44ce
1 parent 2f4f4a8
commit 5ac44ce
Show file tree

Hide file tree

Showing 3 changed files with 39 additions and 2 deletions.
diff --git a/doomsday/sdk/libcore/include/de/filesys/package.h b/doomsday/sdk/libcore/include/de/filesys/package.h
@@ -168,6 +168,10 @@ class DENG2_PUBLIC Package : public IObject
 
     static QStringList tags(File const &packageFile);
 
+    static QStringList tags(String const& tagsString);
+
+    static StringList requires(File const &packageFile);
+
     /**
      * Splits a string containing a package identifier and version. The
      * expected format of the string is `{packageId}_{version}`.

diff --git a/doomsday/sdk/libcore/src/filesys/package.cpp b/doomsday/sdk/libcore/src/filesys/package.cpp
@@ -31,6 +31,7 @@ String const Package::VAR_PACKAGE("package");
 
 static String const PACKAGE_ORDER("package.__order__");
 static String const PACKAGE_IMPORT_PATH("package.importPath");
+static String const PACKAGE_REQUIRES("package.requires");
 
 static String const VAR_ID("ID");
 static String const VAR_PATH("path");
@@ -328,8 +329,25 @@ Record &Package::initializeMetadata(File &packageFile, String const &id)
 
 QStringList Package::tags(File const &packageFile)
 {
-    return packageFile.objectNamespace().gets("package.tags")
-            .split(' ', QString::SkipEmptyParts);
+    return tags(packageFile.objectNamespace().gets(QStringLiteral("package.tags")));
+}
+
+QStringList Package::tags(String const &tagsString)
+{
+    return tagsString.split(' ', QString::SkipEmptyParts);
+}
+
+StringList Package::requires(File const &packageFile)
+{
+    StringList ids;
+    if(packageFile.objectNamespace().has(PACKAGE_REQUIRES))
+    {
+        for(auto const *value : packageFile.objectNamespace().geta(PACKAGE_REQUIRES).elements())
+        {
+            ids << value->asText();
+        }
+    }
+    return ids;
 }
 
 static String stripAfterFirstUnderscore(String str)

diff --git a/doomsday/sdk/libcore/src/filesys/packageloader.cpp b/doomsday/sdk/libcore/src/filesys/packageloader.cpp
@@ -201,6 +201,10 @@ DENG2_PIMPL(PackageLoader)
                                      loaded[packageId]->objectNamespace().gets("path") + "\"");
         }
 
+        // Loads all the packages listed as required for this package. Throws an
+        // exception is any are missing.
+        loadRequirements(source);
+
         Package *pkg = new Package(source);
         loaded.insert(packageId, pkg);
         pkg->setOrder(loadCounter++);
@@ -265,6 +269,17 @@ DENG2_PIMPL(PackageLoader)
         }
     }
 
+    void loadRequirements(File const &packageFile)
+    {
+        for(String const &reqId : Package::requires(packageFile))
+        {
+            if(!self.isLoaded(reqId))
+            {
+                self.load(reqId);
+            }
+        }
+    }
+
     DENG2_PIMPL_AUDIENCE(Activity)
     DENG2_PIMPL_AUDIENCE(Load)
     DENG2_PIMPL_AUDIENCE(Unload)