SampleIncludeProcessor.java

/*
 * Copyright 2016 the original author or authors.
 *
 * 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 org.gradle.docs.asciidoctor;

import org.asciidoctor.ast.Document;
import org.asciidoctor.ast.DocumentRuby;
import org.asciidoctor.extension.IncludeProcessor;
import org.asciidoctor.extension.PreprocessorReader;

import java.util.*;

public class SampleIncludeProcessor extends IncludeProcessor {
    private static final String SAMPLE = "sample";
    private static final Map<String, String> FILE_SUFFIX_TO_SYNTAX = initializeSyntaxMap();

    // Map file suffixes to syntax highlighting where they differ
    private static Map<String, String> initializeSyntaxMap() {
        Map<String, String> map = new HashMap<>();
        map.put("gradle", "groovy");
        map.put("kt", "kotlin");
        map.put("kts", "kotlin");
        map.put("py", "python");
        map.put("sh", "bash");
        map.put("rb", "ruby");
        return Collections.unmodifiableMap(map);
    }

    // Even though these are unused, these constructors are necessary to prevent
    // "(ArgumentError) asciidoctor: FAILED: Failed to load AsciiDoc document - wrong number of arguments (1 for 0)"
    // See https://github.com/asciidoctor/asciidoctorj/issues/451#issuecomment-210914940
    // This is fixed in asciidoctorj 1.6.0
    public SampleIncludeProcessor() {
        super(new HashMap<>());
    }

    public SampleIncludeProcessor(Map<String, Object> config) {
        super(config);
    }

    @Override
    public boolean handles(String target) {
        return target.equals(SAMPLE);
    }

    @Override
    public void process(DocumentRuby document, PreprocessorReader reader, String target, Map<String, Object> attributes) {
        this.process(document(document), reader, target, attributes);
    }

    // This method adheres the asciidoctorj 1.6.0 API
    public void process(Document document, PreprocessorReader reader, String target, Map<String, Object> attributes) {
        if (!attributes.containsKey("dir") || !attributes.containsKey("files")) {
            throw new IllegalStateException("Both the 'dir' and 'files' attributes are required to include a sample");
        }

        String dir = attributes.get("dir").toString();
        List<String> files = Arrays.asList(attributes.get("files").toString().split(";"));

        final String sampleContent = getSampleContent(dir, files);
        reader.push_include(sampleContent, target, target, 1, attributes);
    }

    private String getSourceSyntax(String fileName) {
        String syntax = "txt";
        int i = fileName.lastIndexOf('.');
        if (i > 0) {
            String substring = fileName.substring(i + 1);
            syntax = FILE_SUFFIX_TO_SYNTAX.getOrDefault(substring, substring);
        }
        return syntax;
    }

    private String getSampleContent(String sampleDir, List<String> files) {
        StringBuilder builder = new StringBuilder(String.format("%n[.testable-sample,dir=\"%s\"]%n=====%n", sampleDir));
        for (String fileDeclaration : files) {
            String sourceFilePath = fileDeclaration.replaceAll("\\[[^]]*\\]", "");
            String sourceSyntax = getSourceSyntax(sourceFilePath);
            // FIXME: ensure includes here get processed
            builder.append(String.format(".%s%n[source,%s]%n----%ninclude::%s/%s%n----%n", sourceFilePath, sourceSyntax, sampleDir, fileDeclaration));
        }

        builder.append(String.format("=====%n"));
        return builder.toString();
    }
}