add feature: syntax highlighting for code blocks

Author: YumeiWang

README.md

@@ -1,5 +1,5 @@
 # ConvertTxtMdToHtml
-A command-line tool can process input .txt files into generated .html files.
+A command-line tool can process input .txt or .md files into generated .html files.
 
 ## Installation
 1. Download and Install Java Development Kit according to the Oracle [JDK Installation Guide](https://docs.oracle.com/en/java/javase/20/install/overview-jdk-installation.html#GUID-8677A77F-231A-40F7-98B9-1FD0B48C346A).
@@ -44,6 +44,7 @@ By default, if no output directory is specified, the `.html` files will be saved
 * Automatically parse title from `.txt` / `.md` file.
 * Converts .md syntax links to .html syntax links.
 * Converts .md `---` to `<hr>`.
+* Parse code block and can show line number by adding "showLineNumber" after first triple backticks 
 
 ## Examples
 `java src/ConvertTxtMdToHtml.java ./examples`

convertTxtMdToHtml/testMD.html

@@ -19,6 +19,23 @@ <h1>Example TIL Post</h1>
 <p>When I found a bug, I went to the Issues tab of their GitHub project and clicked New issue.</p>
 <p></p>
 <p>I gave the issue a title and short description as well as a screenshot and submitted the issue.</p>
+<p></p>
+<style>
+pre {
+counter-reset: line;
+background-color: #f4f4f4;
+}
+code::before {
+content: counter(line);
+counter-increment: line;
+padding-right: 10px;
+display: inline-block;
+text-align: right;
+</style>
+<pre><code>const message = 'Hello, world!';</code>
+<code>console.log(message);</code>
+</pre>
+<p></p>
 <p><hr></p>
 <p>Have you heard about <a href="https://hacktoberfest.com/">Hacktoberfest</a>?</p>
 <p></p>

examples/testMD.md

@@ -13,7 +13,13 @@ Once I was familiar with how to run the program, I tried to run some edge cases
 When I found a bug, I went to the Issues tab of their GitHub project and clicked New issue.
 
 I gave the issue a title and short description as well as a screenshot and submitted the issue.
+
+```showLineNumber
+const message = 'Hello, world!';
+console.log(message);
+```
+
 ---
 Have you heard about [Hacktoberfest](https://hacktoberfest.com/)?
 
-Testing --> [Yay][Hacktoberfest](https://hacktoberfest.com/)
+Testing --> [Yay][Hacktoberfest](https://hacktoberfest.com/)

src/ConvertTxtMdToHtml.java

@@ -4,10 +4,10 @@
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-
 public class ConvertTxtMdToHtml {
  private static String DEFAULT_LANG = "en-CA"; // Default language is Canadian English
- private static String OUTPUT ="convertTxtMdToHtml";
+ private static String OUTPUT = "convertTxtMdToHtml";
+
  public static void main(String[] args) {
  // parse arguments
  if (args.length == 0 || args[0].equals("-h") || args[0].equals("--help")) {
@@ -117,13 +117,34 @@ private static void processFile(File inputFile, String outputPath, String lang)
  title = convertLinks(title); // convert links in MD file
  htmlContent.append("<h1>").append(title).append("</h1>\n");
  }
+
+ boolean isInsideCodeBlock = false;
+
  for (String line : lines) {
- if (line.isEmpty()) {
+ if (isInsideCodeBlock) {
+ // If inside a code block, just add the line as-is
+ if (line.trim().equals("```")) {
+ isInsideCodeBlock = false; // Exit the code block
+ htmlContent.append("</pre>\n");
+ } else {
+ htmlContent.append("<code>").append(line).append("</code>\n");
+ }
+ } else if (line.trim().equals("```")||line.trim().equals("```showLineNumber")) {
+ // Start of a code block
+ if( line.trim().equals("```showLineNumber")){
+ htmlContent.append(
+ "<style>\npre {\ncounter-reset: line;\nbackground-color: #f4f4f4;\n}\ncode::before {\ncontent: counter(line);\ncounter-increment: line;\npadding-right: 10px;\ndisplay: inline-block;\ntext-align: right;\n</style>\n<pre>");
+ }else{
+ htmlContent.append(
+ "<style>\npre {\ncounter-reset: line;\nbackground-color: #f4f4f4;\n}\n</style>\n<pre>");
+ }
+ isInsideCodeBlock = true;
+ } else if (line.isEmpty()) {
  htmlContent.append("<p></p>\n"); // Create a new paragraph
  } else {
  if (fileName.endsWith(".md"))
  line = convertHorizontal(line); // convert horizontal in MD file
-  line = convertLinks(line);  // convert links in MD file
+ line = convertLinks(line); // convert links in MD file
  htmlContent.append("<p>").append(line).append("</p>\n");
  }
  }