net.riezebos.thoth.renderers.util.CustomHtmlSerializer.java Source code

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Here is the source code for net.riezebos.thoth.renderers.util.CustomHtmlSerializer.java

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/* Copyright (c) 2016 W.T.J. Riezebos
 *
 * 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 net.riezebos.thoth.renderers.util;

import java.util.List;

import org.apache.commons.lang3.StringUtils;
import org.pegdown.LinkRenderer;
import org.pegdown.ToHtmlSerializer;
import org.pegdown.ast.HeaderNode;
import org.pegdown.ast.InlineHtmlNode;
import org.pegdown.ast.Node;
import org.pegdown.ast.ParaNode;
import org.pegdown.ast.SpecialTextNode;
import org.pegdown.ast.SuperNode;
import org.pegdown.ast.TableNode;
import org.pegdown.ast.TextNode;

import net.riezebos.thoth.util.ThothCoreUtil;
import net.riezebos.thoth.util.ThothUtil;

public class CustomHtmlSerializer extends ToHtmlSerializer {

    public static final String MARKDOWN_TABLE_CLASS = "markdowntable";

    public CustomHtmlSerializer(LinkRenderer linkRenderer) {
        super(linkRenderer);
    }

    // Add class to a table to that Markdown based tables can be separated from any other tables present in the
    // resulting HTML.
    @Override
    public void visit(TableNode node) {
        currentTableNode = node;
        printIndentedTagWithClass(node, "table", MARKDOWN_TABLE_CLASS);
        currentTableNode = null;
    }

    // Add breaks at typical locations so that long lines in tables break better
    @Override
    public void visit(TextNode node) {
        if (currentTableNode != null) {
            String text = ThothCoreUtil.addHtmlBreaks(node.getText());
            if (abbreviations.isEmpty()) {
                printer.print(text);
            } else {
                printWithAbbreviations(text);
            }
        } else
            super.visit(node);
    }

    @Override
    public void visit(SpecialTextNode node) {
        super.visit(node);
        if (currentTableNode != null)
            printer.print("<wbr/>");
    }

    // Suppress printing <p></p> around inline HTML because that makes no sense (might break nesting)
    @Override
    public void visit(ParaNode node) {
        if (isInlineHtml(node))
            printBreakBeforeTag(node, "p");
        else
            visitChildren(node);
    }

    // Add a few extra bookmarks to the header (aliases)
    // Also: embed them inside the header to avoid mis-alignment when navigating
    // (Should be on not before or after the H-tag
    @Override
    public void visit(HeaderNode node) {
        String tag = "h" + node.getLevel();

        boolean startWasNewLine = printer.endsWithNewLine();
        printer.println();
        printer.print('<').print(tag).print('>');
        printer.println();
        writeBookmarks(node);
        visitChildren(node);
        printer.print('<').print('/').print(tag).print('>');
        if (startWasNewLine)
            printer.println();
    }

    protected void writeBookmarks(HeaderNode node) {
        // Headers might be tokenized; so we need to append them together.
        String combinedName = "";
        for (Node child : node.getChildren()) {
            if (child instanceof TextNode) {
                TextNode textNode = (TextNode) child;
                String text = textNode.getText();
                if (text != null && text.trim().length() > 0) {
                    combinedName += text.trim();
                }
            }
        }
        if (StringUtils.isNoneBlank(combinedName)) {
            String ref = ThothUtil.encodeBookmark(combinedName, false);
            writeBookmark(ref);

            // Also add a bookmark that excludes any (potentially) generated numbers as a prefix of the title
            int idx = 0;
            for (int i = 0; i < ref.length(); i++, idx++) {
                if (!Character.isDigit(ref.charAt(i)) && ref.charAt(i) != '.')
                    break;
            }
            if (idx != 0) {
                String alternate = ref.substring(idx).trim();
                writeBookmark(alternate);
            }
        }
    }

    protected void writeBookmark(String alias) {
        printer.print("<a name=\"" + alias + "\" style=\"display:block\"></a>");
        if (!alias.equals(alias.toLowerCase()))
            writeBookmark(alias.toLowerCase());
    }

    protected void printIndentedTagWithClass(SuperNode node, String tag, String className) {
        printer.println().print('<').print(tag).print(" class=\"" + className + "\"").print('>').indent(+2);
        visitChildren(node);
        printer.indent(-2).println().print('<').print('/').print(tag).print('>');
    }

    protected boolean isInlineHtml(ParaNode node) {
        boolean makeParagraph = true;
        List<Node> children = node.getChildren();
        if (!children.isEmpty() && children.get(0) instanceof SuperNode) {
            Node superNode = children.get(0);
            List<Node> childrenOfSuper = superNode.getChildren();
            if (!childrenOfSuper.isEmpty()) {
                Node nestedChild = childrenOfSuper.get(0);
                makeParagraph = !(nestedChild instanceof InlineHtmlNode);
            }
        }
        return makeParagraph;
    }
}