[core] Refactor templating management

modules/openapi-generator-cli/src/main/java/org/openapitools/codegen/cmd/Meta.java

@@ -30,6 +30,7 @@
 import org.openapitools.codegen.CodegenConfig;
 import org.openapitools.codegen.DefaultGenerator;
 import org.openapitools.codegen.SupportingFile;
+import org.openapitools.codegen.TemplateManager;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -146,9 +147,9 @@ public File convert(SupportingFile support) {
                             new File(new File(targetDir.getAbsolutePath()), support.folder);
                     File outputFile = new File(destinationFolder, support.destinationFilename);
 
-                    String template =
-                            generator.readTemplate(new File(TEMPLATE_DIR_CLASSPATH,
-                                    support.templateFile).getPath());
+                    String template =((TemplateManager)generator.getTemplateProcessor()).readTemplate(new File(TEMPLATE_DIR_CLASSPATH,
+                            support.templateFile).getPath());
+
                     String formatted = template;
 
                     if (support.templateFile.endsWith(MUSTACHE_EXTENSION)) {
@@ -180,7 +181,7 @@ private static Mustache.TemplateLoader loader(final DefaultGenerator generator)
         return new Mustache.TemplateLoader() {
             @Override
             public Reader getTemplate(String name) {
-                return generator.getTemplateReader(TEMPLATE_DIR_CLASSPATH + File.separator
+                return ((TemplateManager)generator.getTemplateProcessor()).getTemplateReader(TEMPLATE_DIR_CLASSPATH + File.separator
                         + name.concat(MUSTACHE_EXTENSION));
             }
         };

modules/openapi-generator-core/src/main/java/org/openapitools/codegen/api/TemplatePathLocator.java

@@ -0,0 +1,14 @@
+package org.openapitools.codegen.api;
+
+/**
+ * Provides means for searching for "actual" template location based on relative template file.
+ */
+public interface TemplatePathLocator {
+    /**
+     * Get the full path to a relative template file.
+     *
+     * @param relativeTemplateFile Template file
+     * @return String Full template file path
+     */
+    String getFullTemplatePath(String relativeTemplateFile);
+}

modules/openapi-generator-core/src/main/java/org/openapitools/codegen/api/TemplateProcessor.java

@@ -0,0 +1,56 @@
+package org.openapitools.codegen.api;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.Map;
+
+/**
+ * Interface for abstractions around writing templated data to a file.
+ */
+public interface TemplateProcessor {
+    /**
+     * Writes data to a compiled template
+     *
+     * @param data Input data
+     * @param template Input template location
+     * @param target The targeted file output location
+     *
+     * @return The actual file
+     */
+    File write(Map<String, Object> data, String template, File target) throws IOException;
+
+    /**
+     * Write bytes to a file
+     *
+     * @param filename The name of file to write
+     * @param contents The contents bytes.  Typically this is a UTF-8 formatted string.
+     * @return File representing the written file.
+     * @throws IOException If file cannot be written.
+     */
+    File writeToFile(String filename, byte[] contents) throws IOException;
+
+    /**
+     * Allow a caller to mark a path as ignored with accompanying reason
+     *
+     * @param path The ignored path
+     * @param context The reason for ignoring this path
+     */
+    void ignore(Path path, String context);
+
+    /**
+     * Allow a caller to mark a path as skipped with accompanying reason
+     *
+     * @param path The skipped path
+     * @param context The reason for skipping this path
+     */
+    void skip(Path path, String context);
+
+    /**
+     * Allow a caller to mark a path having errored during processing with accompanying reason
+     *
+     * @param path The path which has caused an error
+     * @param context The reason for the error
+     */
+    default void error(Path path, String context) { };
+}

modules/openapi-generator-core/src/main/java/org/openapitools/codegen/api/TemplatingEngineAdapter.java

@@ -36,27 +36,27 @@ public interface TemplatingEngineAdapter {
      */
     String getIdentifier();
 
+    /**
+     * During generation, if a supporting file has a file extension that is
+     * inside that array, then it is considered a templated supporting file
+     * and we use the templating engine adapter to generate it
+     *
+     * @return string array of the valid file extensions for this templating engine
+     */
+    String[] getFileExtensions();
+
     /**
      * Compiles a template into a string
      *
-     * @param generator    From where we can fetch the templates content (e.g. an instance of DefaultGenerator)
+     * @param executor    From where we can fetch the templates content (e.g. an instance of DefaultGenerator)
      * @param bundle       The map of values to pass to the template
      * @param templateFile The name of the template (e.g. model.mustache )
      * @return the processed template result
      * @throws IOException an error ocurred in the template processing
      */
-    String compileTemplate(TemplatingGenerator generator, Map<String, Object> bundle,
+    String compileTemplate(TemplatingExecutor executor, Map<String, Object> bundle,
                            String templateFile) throws IOException;
 
-    /**
-     * During generation, if a supporting file has a file extension that is
-     * inside that array, then it is considered a templated supporting file
-     * and we use the templating engine adapter to generate it
-     *
-     * @return string array of the valid file extensions for this templating engine
-     */
-    String[] getFileExtensions();
-
     /**
      * Determines whether the template file with supported extensions exists. This may be on the filesystem,
      * external filesystem, or classpath (implementation is up to TemplatingGenerator).
@@ -65,7 +65,7 @@ String compileTemplate(TemplatingGenerator generator, Map<String, Object> bundle
      * @param templateFile The original target filename
      * @return True if the template is available in the template search path, false if it can not be found
      */
-    default boolean templateExists(TemplatingGenerator generator, String templateFile) {
+    default boolean templateExists(TemplatingExecutor generator, String templateFile) {
         return Arrays.stream(getFileExtensions()).anyMatch(ext -> {
             int idx = templateFile.lastIndexOf(".");
             String baseName;

modules/openapi-generator-core/src/main/java/org/openapitools/codegen/api/TemplatingExecutor.java

@@ -0,0 +1,26 @@
+package org.openapitools.codegen.api;
+
+import java.nio.file.Path;
+
+/**
+ * interface to the full template content
+ * implementers might take into account the -t cli option,
+ * look in the resources for a generator specific template, etc
+ */
+public interface TemplatingExecutor {
+    /**
+     * returns the template content by name
+     *
+     * @param name the template name (e.g. model.mustache)
+     * @return the contents of that template
+     */
+    String getFullTemplateContents(String name);
+
+    /**
+     * Returns the path of a template, allowing access to the template where consuming literal contents aren't desirable or possible.
+     *
+     * @param name the template name (e.g. model.mustache)
+     * @return The {@link Path} to the template
+     */
+    Path getFullTemplatePath(String name);
+}

modules/openapi-generator-core/src/main/java/org/openapitools/codegen/api/TemplatingGenerator.java

@@ -16,28 +16,16 @@
 
 package org.openapitools.codegen.api;
 
-import java.nio.file.Path;
-
+// TODO: 6.0 Remove
 /**
  * interface to the full template content
  * implementers might take into account the -t cli option,
  * look in the resources for a language specific template, etc
+ *
+ * @deprecated as of 5.0, replaced by {@link TemplatingExecutor}
+ * @apiNote Deprecation is considered low-impact breaking change because tooling only supports internal implementations.
  */
-public interface TemplatingGenerator {
-
-    /**
-     * returns the template content by name
-     *
-     * @param name the template name (e.g. model.mustache)
-     * @return the contents of that template
-     */
-    String getFullTemplateContents(String name);
+@Deprecated()
+public interface TemplatingGenerator extends TemplatingExecutor {
 
-    /**
-     * Returns the path of a template, allowing access to the template where consuming literal contents aren't desirable or possible.
-     *
-     * @param name the template name (e.g. model.mustache)
-     * @return The {@link Path} to the template
-     */
-    Path getFullTemplatePath(String name);
 }

modules/openapi-generator-gradle-plugin/src/main/kotlin/org/openapitools/generator/gradle/plugin/tasks/MetaTask.kt

@@ -24,10 +24,7 @@ import org.gradle.api.tasks.TaskAction
 import org.gradle.internal.logging.text.StyledTextOutput
 import org.gradle.internal.logging.text.StyledTextOutputFactory
 import org.gradle.kotlin.dsl.property
-import org.openapitools.codegen.CodegenConfig
-import org.openapitools.codegen.CodegenConstants
-import org.openapitools.codegen.DefaultGenerator
-import org.openapitools.codegen.SupportingFile
+import org.openapitools.codegen.*
 import java.io.File
 import java.io.IOException
 import java.nio.charset.Charset
@@ -90,9 +87,17 @@ open class MetaTask : DefaultTask() {
                 destinationFolder.mkdirs()
                 val outputFile = File(destinationFolder, it.destinationFilename)
 
-                val template = generator.readTemplate(File("codegen", it.templateFile).path)
+                val templateProcessor = generator.templateProcessor as TemplateManager
+
+                val template = templateProcessor.getFullTemplateContents(File("codegen", it.templateFile).path)
                 var formatted = template
 
+                val loader: (DefaultGenerator) -> Mustache.TemplateLoader = { g ->
+                        Mustache.TemplateLoader { name ->
+                            templateProcessor.getTemplateReader("codegen${File.separator}$name.mustache")
+                        }
+                }
+
                 if (it.templateFile.endsWith(".mustache")) {
                     formatted = Mustache.compiler()
                             .withLoader(loader(generator))
@@ -115,12 +120,6 @@ open class MetaTask : DefaultTask() {
         out.formatln("Created generator %s", klass)
     }
 
-    private fun loader(generator: DefaultGenerator): Mustache.TemplateLoader {
-        return Mustache.TemplateLoader { name ->
-            generator.getTemplateReader("codegen${File.separator}$name.mustache")
-        }
-    }
-
     private fun String.titleCasedTextOnly(): String =
             this.split(Regex("[^a-zA-Z0-9]")).joinToString(separator = "", transform = String::capitalize)
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenConfig.java

@@ -247,8 +247,6 @@ public interface CodegenConfig {
 
     String getDocExtension();
 
-    String getCommonTemplateDir();
-
     void setIgnoreFilePathOverride(String ignoreFileOverride);
 
     String getIgnoreFilePathOverride();

modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java

@@ -163,7 +163,6 @@ apiTemplateFiles are for API outputs only (controllers/handlers).
     protected Map<String, String> reservedWordsMappings = new HashMap<String, String>();
     protected String templateDir;
     protected String embeddedTemplateDir;
-    protected String commonTemplateDir = "_common";
     protected Map<String, Object> additionalProperties = new HashMap<String, Object>();
     protected Map<String, String> serverVariables = new HashMap<String, String>();
     protected Map<String, Object> vendorExtensions = new HashMap<String, Object>();
@@ -946,14 +945,6 @@ public String embeddedTemplateDir() {
         }
     }
 
-    public String getCommonTemplateDir() {
-        return this.commonTemplateDir;
-    }
-
-    public void setCommonTemplateDir(String commonTemplateDir) {
-        this.commonTemplateDir = commonTemplateDir;
-    }
-
     public Map<String, String> apiDocTemplateFiles() {
         return apiDocTemplateFiles;
     }
@@ -1426,12 +1417,6 @@ public DefaultCodegen() {
         importMapping.put("LocalDate", "org.joda.time.*");
         importMapping.put("LocalTime", "org.joda.time.*");
 
-        // we've used the .openapi-generator-ignore approach as
-        // suppportingFiles can be cleared by code generator that extends
-        // the default codegen, leaving the commented code below for
-        // future reference
-        //supportingFiles.add(new GlobalSupportingFile("LICENSE", "LICENSE"));
-
         cliOptions.add(CliOption.newBoolean(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG,
                 CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG_DESC).defaultValue(Boolean.TRUE.toString()));
         cliOptions.add(CliOption.newBoolean(CodegenConstants.SORT_MODEL_PROPERTIES_BY_REQUIRED_FLAG,