1 files changed, 23 insertions, 0 deletions
diff --git a/src/main/scala/xyz/driver/restquery/rest/parsers/PaginationParser.scala b/src/main/scala/xyz/driver/restquery/rest/parsers/PaginationParser.scala
new file mode 100644
index 0000000..2b4547b
--- /dev/null
+++ b/src/main/scala/xyz/driver/restquery/rest/parsers/PaginationParser.scala
@@ -0,0 +1,23 @@
+package xyz.driver.restquery.http.parsers
+
+import xyz.driver.restquery.domain.Pagination
+
+import scala.util._
+
+object PaginationParser {
+
+  def parse(query: Seq[(String, String)]): Try[Pagination] = {
+    val IntString = """(\d+)""".r
+    def validate(field: String, default: Int) = query.collectFirst { case (`field`, size) => size } match {
+      case Some(IntString(x)) if x.toInt > 0 => x.toInt
+      case Some(IntString(x))                => throw new ParseQueryArgException((field, s"must greater than zero (found $x)"))
+      case Some(str)                         => throw new ParseQueryArgException((field, s"must be an integer (found $str)"))
+      case None                              => default
+    }
+
+    Try {
+      Pagination(validate("pageSize", Pagination.Default.pageSize),
+                 validate("pageNumber", Pagination.Default.pageNumber))
+    }
+  }
+}