Add formatted date placeholder

src/main/kotlin/de/idetools/filename_template/InitializeFilenameTemplateActivity.kt

@@ -6,6 +6,7 @@ import com.intellij.openapi.actionSystem.Constraints
 import com.intellij.openapi.actionSystem.DefaultActionGroup
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.startup.StartupActivity
+import de.idetools.filename_template.placeholders.DatePlaceholder
 import de.idetools.filename_template.placeholders.DefaultPlaceholder
 import de.idetools.filename_template.placeholders.EpochPlaceholder
 import de.idetools.filename_template.placeholders.PlaceholderProcessor
@@ -21,6 +22,7 @@ class InitializeFilenameTemplateActivity : StartupActivity {
 
         val placeholders = listOf(
             EpochPlaceholder(),
+            DatePlaceholder(),
             DefaultPlaceholder()
         )
 

src/main/kotlin/de/idetools/filename_template/placeholders/DatePlaceholder.kt

@@ -0,0 +1,20 @@
+package de.idetools.filename_template.placeholders
+
+import java.time.LocalDateTime
+import java.time.format.DateTimeFormatter
+
+class DatePlaceholder : Placeholder {
+    override fun supports(placeholder: String): Boolean = placeholder.startsWith("DATE")
+
+    override fun process(placeholder: String, context: PlaceholderContext): String {
+        val date = LocalDateTime.now()
+        val datePattern = placeholder.substringAfter(":", "")
+        val formatter =
+            if (datePattern.isBlank()) {
+                DateTimeFormatter.ISO_DATE
+            } else {
+                DateTimeFormatter.ofPattern(datePattern)
+            }
+        return date.format(formatter)
+    }
+}

src/main/resources/META-INF/plugin.xml

@@ -35,6 +35,12 @@
             <br/>
             <p>A template might contain following place holders:</p>
             <dl>
+                <dt>{DATE:FORMAT}</dt>
+                <dd>
+                    The formatted date. If the format is omitted "yyyy-MM-dd" is used by default.<br />
+                    See the java documentation for supported patterns: <a href="https://docs.oracle.com/en/java/javase/15/docs/api/java.base/java/time/format/DateTimeFormatter.html">Patterns for Formatting and Parsing</a>
+                </dd>
+
                 <dt>{EPOCH}</dt>
                 <dd>The current unix time stamp: Seconds since the Unix Epoch on January 1st, 1970 at UTC.</dd>
             </dl>