Custom HTML support #355 (#1129)

* test

* settings

* version

src/main/java/stirling/software/SPDF/config/FileFallbackTemplateResolver.java

@@ -0,0 +1,48 @@
+package stirling.software.SPDF.config;
+
+import java.io.IOException;
+import java.util.Map;
+
+import org.springframework.core.io.Resource;
+import org.springframework.core.io.ResourceLoader;
+import org.thymeleaf.IEngineConfiguration;
+import org.thymeleaf.templateresolver.AbstractConfigurableTemplateResolver;
+import org.thymeleaf.templateresource.ClassLoaderTemplateResource;
+import org.thymeleaf.templateresource.FileTemplateResource;
+import org.thymeleaf.templateresource.ITemplateResource;
+
+public class FileFallbackTemplateResolver extends AbstractConfigurableTemplateResolver {
+
+    private final ResourceLoader resourceLoader;
+
+    public FileFallbackTemplateResolver(ResourceLoader resourceLoader) {
+        super();
+        this.resourceLoader = resourceLoader;
+        setSuffix(".html");
+    }
+
+    // Note this does not work in local IDE, Prod jar only.
+    @Override
+    protected ITemplateResource computeTemplateResource(
+            IEngineConfiguration configuration,
+            String ownerTemplate,
+            String template,
+            String resourceName,
+            String characterEncoding,
+            Map<String, Object> templateResolutionAttributes) {
+        Resource resource =
+                resourceLoader.getResource("file:./customFiles/templates/" + resourceName);
+        try {
+            if (resource.exists() && resource.isReadable()) {
+                return new FileTemplateResource(resource.getFile().getPath(), characterEncoding);
+            }
+        } catch (IOException e) {
+            
+        }
+
+        return new ClassLoaderTemplateResource(
+                Thread.currentThread().getContextClassLoader(),
+                "classpath:/templates/" + resourceName,
+                characterEncoding);
+    }
+}