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// Copyright 2018 The Bazel Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.google.devtools.build.skydoc.rendering;
import static java.nio.charset.StandardCharsets.UTF_8;
import com.google.devtools.build.skydoc.rendering.proto.StardocOutputProtos.AspectInfo;
import com.google.devtools.build.skydoc.rendering.proto.StardocOutputProtos.ModuleInfo;
import com.google.devtools.build.skydoc.rendering.proto.StardocOutputProtos.ProviderInfo;
import com.google.devtools.build.skydoc.rendering.proto.StardocOutputProtos.RuleInfo;
import com.google.devtools.build.skydoc.rendering.proto.StardocOutputProtos.StarlarkFunctionInfo;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringWriter;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.VelocityEngine;
import org.apache.velocity.exception.MethodInvocationException;
import org.apache.velocity.exception.ParseErrorException;
import org.apache.velocity.exception.ResourceNotFoundException;
import org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader;
import org.apache.velocity.runtime.resource.loader.JarResourceLoader;
/**
* Produces skydoc output in markdown form.
*/
public class MarkdownRenderer {
// TODO(kendalllane): Refactor MarkdownRenderer to take in something other than filepaths.
private final String headerTemplateFilename;
private final String ruleTemplateFilename;
private final String providerTemplateFilename;
private final String functionTemplateFilename;
private final String aspectTemplateFilename;
private final VelocityEngine velocityEngine;
public MarkdownRenderer(
String headerTemplate,
String ruleTemplate,
String providerTemplate,
String functionTemplate,
String aspectTemplate) {
this.headerTemplateFilename = headerTemplate;
this.ruleTemplateFilename = ruleTemplate;
this.providerTemplateFilename = providerTemplate;
this.functionTemplateFilename = functionTemplate;
this.aspectTemplateFilename = aspectTemplate;
this.velocityEngine = new VelocityEngine();
velocityEngine.setProperty("resource.loader", "classpath, jar");
velocityEngine.setProperty("classpath.resource.loader.class",
ClasspathResourceLoader.class.getName());
velocityEngine.setProperty("jar.resource.loader.class", JarResourceLoader.class.getName());
velocityEngine.setProperty("input.encoding", "UTF-8");
velocityEngine.setProperty("output.encoding", "UTF-8");
velocityEngine.setProperty("runtime.references.strict", true);
}
/**
* Returns a markdown header string that should appear at the top of Stardoc's output, providing a
* summary for the input Starlark module.
*/
public String renderMarkdownHeader(ModuleInfo moduleInfo) throws IOException {
VelocityContext context = new VelocityContext();
context.put("util", new MarkdownUtil());
context.put("moduleDocstring", moduleInfo.getModuleDocstring());
StringWriter stringWriter = new StringWriter();
Reader reader = readerFromPath(headerTemplateFilename);
try {
velocityEngine.evaluate(context, stringWriter, headerTemplateFilename, reader);
} catch (ResourceNotFoundException | ParseErrorException | MethodInvocationException e) {
throw new IOException(e);
}
return stringWriter.toString();
}
/**
* Returns a markdown rendering of rule documentation for the given rule information object with
* the given rule name.
*/
public String render(String ruleName, RuleInfo ruleInfo) throws IOException {
VelocityContext context = new VelocityContext();
context.put("util", new MarkdownUtil());
context.put("ruleName", ruleName);
context.put("ruleInfo", ruleInfo);
StringWriter stringWriter = new StringWriter();
Reader reader = readerFromPath(ruleTemplateFilename);
try {
velocityEngine.evaluate(context, stringWriter, ruleTemplateFilename, reader);
} catch (ResourceNotFoundException | ParseErrorException | MethodInvocationException e) {
throw new IOException(e);
}
return stringWriter.toString();
}
/**
* Returns a markdown rendering of provider documentation for the given provider information
* object with the given name.
*/
public String render(String providerName, ProviderInfo providerInfo) throws IOException {
VelocityContext context = new VelocityContext();
context.put("util", new MarkdownUtil());
context.put("providerName", providerName);
context.put("providerInfo", providerInfo);
StringWriter stringWriter = new StringWriter();
Reader reader = readerFromPath(providerTemplateFilename);
try {
velocityEngine.evaluate(context, stringWriter, providerTemplateFilename, reader);
} catch (ResourceNotFoundException | ParseErrorException | MethodInvocationException e) {
throw new IOException(e);
}
return stringWriter.toString();
}
/**
* Returns a markdown rendering of a user-defined function's documentation for the function info
* object.
*/
public String render(StarlarkFunctionInfo functionInfo) throws IOException {
VelocityContext context = new VelocityContext();
context.put("util", new MarkdownUtil());
context.put("funcInfo", functionInfo);
StringWriter stringWriter = new StringWriter();
Reader reader = readerFromPath(functionTemplateFilename);
try {
velocityEngine.evaluate(context, stringWriter, functionTemplateFilename, reader);
} catch (ResourceNotFoundException | ParseErrorException | MethodInvocationException e) {
throw new IOException(e);
}
return stringWriter.toString();
}
/**
* Returns a markdown rendering of aspect documentation for the given aspect information object
* with the given aspect name.
*/
public String render(String aspectName, AspectInfo aspectInfo) throws IOException {
VelocityContext context = new VelocityContext();
context.put("util", new MarkdownUtil());
context.put("aspectName", aspectName);
context.put("aspectInfo", aspectInfo);
StringWriter stringWriter = new StringWriter();
Reader reader = readerFromPath(aspectTemplateFilename);
try {
velocityEngine.evaluate(context, stringWriter, aspectTemplateFilename, reader);
} catch (ResourceNotFoundException | ParseErrorException | MethodInvocationException e) {
throw new IOException(e);
}
return stringWriter.toString();
}
/**
* Returns a reader from the given path.
*
* @param filePath The given path, either a filesystem path or a java Resource
*/
private static Reader readerFromPath(String filePath) throws IOException {
if (Files.exists(Paths.get(filePath))) {
Path path = Paths.get(filePath);
return Files.newBufferedReader(path);
}
InputStream inputStream = MarkdownRenderer.class.getClassLoader().getResourceAsStream(filePath);
if (inputStream == null) {
throw new FileNotFoundException(filePath + " was not found as a resource.");
}
return new InputStreamReader(inputStream, UTF_8);
}
}