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Merged
MikeMirzayanov merged 3 commits into from
Jun 3, 2025
Merged

Css vars supported in component LESS #54

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97ffefb
Unused import
MikeMirzayanov Mar 15, 2025
6e251b9
Merge remote-tracking branch 'origin/master' into dev-mikemirzayanov
MikeMirzayanov Mar 15, 2025
41d52f0
Css vars supported in component LESS
MikeMirzayanov Jun 3, 2025
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2 changes: 1 addition & 1 deletion code/pom.xml
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Original file line number Diff line number Diff line change
Expand Up @@ -287,7 +287,7 @@
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
<version>3.14.0</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
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1 change: 0 additions & 1 deletion code/src/main/java/org/nocturne/main/PageLoader.java
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Expand Up @@ -3,7 +3,6 @@
*/
package org.nocturne.main;

import com.google.common.base.Throwables;
import org.apache.log4j.Logger;
import org.nocturne.exception.ConfigurationException;
import org.nocturne.pool.PagePool;
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77 changes: 64 additions & 13 deletions code/src/main/java/org/nocturne/template/impl/Less.java
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Original file line number Diff line number Diff line change
Expand Up @@ -3,29 +3,66 @@
import com.github.sommeri.less4j.Less4jException;
import com.github.sommeri.less4j.LessCompiler;
import com.github.sommeri.less4j.core.DefaultLessCompiler;
import org.apache.commons.lang3.RandomStringUtils;
import org.apache.log4j.Logger;
import org.nocturne.util.StringUtil;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.io.*;
import java.nio.charset.StandardCharsets;
import java.util.Objects;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
* @author MikeMirzayanov (mirzayanovmr@gmail.com)
*/
public class Less {
private static final Logger logger = Logger.getLogger(Less.class);

// Matches var(--variable-name) where variable name uses valid identifier symbols
private static final Pattern BEFORE_REPL_CSS_VAR_PATTERN = Pattern.compile("var\\(--([\\w-]+)\\)");
private static final Pattern AFTER_REPL_CSS_VAR_PATTERN = Pattern.compile("nocturne-rpl-var--([\\w-]+)");

private static final String CACHE_OPEN_TAG = "<cache>";
private static final String CACHE_CLOSE_TAG = "</cache>";
private static File tmpDir;
private static final File tmpDir;

// Replaces all var(--id) with nocturne-rpl-var--id
@SuppressWarnings("StringBufferMayBeStringBuilder")
private static String preprocessCssVars(String lessCode) {
Matcher m = BEFORE_REPL_CSS_VAR_PATTERN.matcher(lessCode);
StringBuffer result = new StringBuffer();
while (m.find()) {
m.appendReplacement(result, "nocturne-rpl-var--" + m.group(1));
}
m.appendTail(result);
return result.toString();
}

// Replaces all nocturne-rpl-var--id with var(--id)
@SuppressWarnings("StringBufferMayBeStringBuilder")
private static String postprocessCssVars(String cssCode) {
Matcher m = AFTER_REPL_CSS_VAR_PATTERN.matcher(cssCode);
StringBuffer result = new StringBuffer();
while (m.find()) {
m.appendReplacement(result, "var(--" + m.group(1) + ")");
}
m.appendTail(result);
return result.toString();
}

@SuppressWarnings("ResultOfMethodCallIgnored")
public static synchronized String compile(@Nonnull Object source, @Nonnull String lessCode, @Nullable File commonsFile) throws IOException {
public static synchronized String compile(@Nonnull Object source,
@Nonnull String lessCode,
@Nullable File commonsFile) throws IOException {
long commonsFileLastModified = commonsFile == null ? 0 : commonsFile.lastModified();
long commonsFileLength = commonsFile == null ? 0 : commonsFile.length();
String cacheKey = getName(source).trim() + "_" + commonsFileLastModified + "_" + commonsFileLength + "_" + hash(lessCode);
String cacheKey = getName(source).trim()
+ "_" + commonsFileLastModified
+ "_" + commonsFileLength
+ "_" + hash(lessCode);

File cacheDir = new File(tmpDir, "cache");
if (!cacheDir.isDirectory()) {
Expand All @@ -46,6 +83,7 @@ public static synchronized String compile(@Nonnull Object source, @Nonnull Strin
return css;
}
}

if (cacheFile.exists()) {
cacheFile.delete();
}
Expand All @@ -59,10 +97,11 @@ public static synchronized String compile(@Nonnull Object source, @Nonnull Strin
File workCommonsFile;
if (commonsFile != null) {
workCommonsFile = new File(workDir, commonsFile.getName());
writeFile(workCommonsFile, readFile(commonsFile));
lessCode = "@import \"" + commonsFile.getName() + "\";\n" + lessCode;
writeFile(workCommonsFile, preprocessCssVars(readFile(commonsFile)));
lessCode = "@import \"" + commonsFile.getName() + "\";\n" + preprocessCssVars(lessCode);
} else {
workCommonsFile = null;
lessCode = preprocessCssVars(lessCode);
}

File workMainFile = new File(workDir, "main.less");
Expand All @@ -73,8 +112,12 @@ public static synchronized String compile(@Nonnull Object source, @Nonnull Strin
try {
LessCompiler.CompilationResult compilationResult = compiler.compile(workMainFile);
String cachedResult = CACHE_OPEN_TAG + compilationResult.getCss() + CACHE_CLOSE_TAG;
writeFile(cacheFile, cachedResult);
return compilationResult.getCss();

File tmpCacheFile = new File(cacheDir, RandomStringUtils.randomAlphabetic(32));
writeFile(tmpCacheFile, cachedResult);
tmpCacheFile.renameTo(cacheFile);

return postprocessCssVars(compilationResult.getCss());
} catch (Less4jException e) {
throw new IOException("Can't compile less code in \"" + source + "\": " + e.getMessage(), e);
}
Expand Down Expand Up @@ -113,14 +156,14 @@ private static long hash(String css) {
return a ^ b;
}

private static void writeFile(File file, String content) throws FileNotFoundException {
try (PrintWriter writer = new PrintWriter(file)) {
writer.print(content);
private static void writeFile(File file, String content) throws IOException {
try (Writer writer = new OutputStreamWriter(new FileOutputStream(file), StandardCharsets.UTF_8)) {
writer.write(content);
}
}

private static String readFile(File file) throws IOException {
try (FileReader reader = new FileReader(file)) {
try (Reader reader = new InputStreamReader(new FileInputStream(file), StandardCharsets.UTF_8)) {
StringBuilder result = new StringBuilder((int) file.length());
char[] buffer = new char[65536];
int len;
Expand All @@ -140,11 +183,19 @@ private static String readFile(File file) throws IOException {
tmpDir = new File(tmpFile.getParentFile(), "nocturne-less-tmp");
if (!tmpDir.isDirectory()) {
if (!tmpDir.mkdirs()) {
throw new IOException("Can't create " + tmpFile + ".");
throw new IOException("Can't create " + tmpDir + ".");
}
}
} catch (IOException e) {
e.printStackTrace();
String message = "Unable to validate temp directory before using Less engine: " + e.getMessage();

System.out.println(message);
e.printStackTrace(System.out);

System.err.println(message);
e.printStackTrace(System.err);

throw new RuntimeException(message, e);
}
}
}