diff -r d8ec2d8ffa82 -r ca5501d851fa src/main/kotlin/de/uapcore/lightpit/viewmodel/Issues.kt
--- a/src/main/kotlin/de/uapcore/lightpit/viewmodel/Issues.kt	Tue Jan 03 18:25:51 2023 +0100
+++ b/src/main/kotlin/de/uapcore/lightpit/viewmodel/Issues.kt	Sun Jan 08 17:07:26 2023 +0100
@@ -31,6 +31,7 @@
 import com.vladsch.flexmark.parser.Parser
 import com.vladsch.flexmark.util.data.MutableDataSet
 import com.vladsch.flexmark.util.data.SharedDataKeys
+import de.uapcore.lightpit.HttpRequest
 import de.uapcore.lightpit.entities.*
 import de.uapcore.lightpit.types.*
 import kotlin.math.roundToInt
@@ -111,8 +112,9 @@
         val options = MutableDataSet()
             .set(SharedDataKeys.EXTENSIONS, listOf(TablesExtension.create(), StrikethroughExtension.create()))
         parser = Parser.builder(options).build()
-        renderer = HtmlRenderer.builder(options
-            .set(HtmlRenderer.ESCAPE_HTML, true)
+        renderer = HtmlRenderer.builder(
+            options
+                .set(HtmlRenderer.ESCAPE_HTML, true)
         ).build()
 
         issue.description = formatMarkdown(issue.description ?: "")
@@ -164,3 +166,57 @@
     }
 }
 
+class IssueFilter(http: HttpRequest) {
+
+    val issueStatus = IssueStatus.values()
+    val issueCategory = IssueCategory.values()
+    val flagIncludeDone = "f.0"
+    val flagMine = "f.1"
+    val flagBlocker = "f.2"
+
+    val includeDone: Boolean = evalFlag(http, flagIncludeDone)
+    val onlyMine: Boolean = evalFlag(http, flagMine)
+    val onlyBlocker: Boolean = evalFlag(http, flagBlocker)
+    val status: List<IssueStatus> = evalEnum(http, "s")
+    val category: List<IssueCategory> = evalEnum(http, "c")
+
+    private fun evalFlag(http: HttpRequest, name: String): Boolean {
+        val param = http.paramArray("filter")
+        if (param.isNotEmpty()) {
+            if (param.contains(name)) {
+                http.session.setAttribute(name, true)
+            } else {
+                http.session.removeAttribute(name)
+            }
+        }
+        return http.session.getAttribute(name) != null
+    }
+
+    private inline fun <reified T : Enum<T>> evalEnum(http: HttpRequest, prefix: String): List<T> {
+        val sattr = "f.${prefix}"
+        val param = http.paramArray("filter")
+        if (param.isNotEmpty()) {
+            val list = param.filter { it.startsWith("${prefix}.") }
+                .map { it.substring(prefix.length + 1) }
+                .map {
+                    try {
+                        // quick and very dirty validation
+                        enumValueOf<T>(it)
+                    } catch (_: IllegalArgumentException) {
+                        // skip
+                    }
+                }
+            if (list.isEmpty()) {
+                http.session.removeAttribute(sattr)
+            } else {
+                http.session.setAttribute(sattr, list.joinToString(","))
+            }
+        }
+
+        return http.session.getAttribute(sattr)
+            ?.toString()
+            ?.split(",")
+            ?.map { enumValueOf(it) }
+            ?: emptyList()
+    }
+}