Fix cross_todo example

examples/cross_todo/nim_backend/testbackend.nim

@@ -0,0 +1,83 @@
+# Tests the backend code.
+
+import backend, db_sqlite, strutils, times
+
+
+proc showPagedResults(conn: TDbConn; params: TPagedParams) =
+  ## Shows the contents of the database in pages of specified size.
+  ##
+  ## Hmm... I guess this is more of a debug proc which should be moved outside,
+  ## or to a commandline interface (hint).
+  var
+    page = 0'i64
+    rows = conn.getPagedTodos(params)
+
+  while rows.len > 0:
+    echo("page " & $page)
+    for row in rows:
+      echo("row id:$1, text:$2, priority:$3, done:$4, date:$5" % [$row.getId,
+        $row.text, $row.priority, $row.isDone,
+        $row.getModificationDate])
+    # Query the database for the next page or quit.
+    if params.pageSize > 0:
+      page = page + 1
+      rows = conn.getPagedTodos(params, page)
+    else:
+      break
+
+
+proc dumTest() =
+  let conn = openDatabase("todo.sqlite3")
+  try:
+    let numTodos = conn.getNumEntries
+    echo("Current database contains " & $numTodos & " todo items.")
+    if numTodos < 10:
+      # Fill some dummy rows if there are not many entries yet.
+      discard conn.addTodo(3, "Filler1")
+      discard conn.addTodo(4, "Filler2")
+
+    var todo = conn.addTodo(2, "Testing")
+    echo("New todo added with id " & $todo.getId)
+
+    # Try changing it and updating the database.
+    var clonedTodo = conn.getTodo(todo.getId)[]
+    assert(clonedTodo.text == todo.text, "Should be equal")
+    todo.text = "Updated!"
+    todo.priority = 7
+    todo.isDone = true
+    if todo.save(conn):
+      echo("Updated priority $1, done $2" % [$todo.priority, $todo.isDone])
+    else:
+      assert(false, "Uh oh, I wasn't expecting that!")
+
+    # Verify our cloned copy is different but can be updated.
+    assert(clonedTodo.text != todo.text, "Should be different")
+    discard clonedTodo.update(conn)
+    assert(clonedTodo.text == todo.text, "Should be equal")
+
+    var params: TPagedParams
+    params.initDefaults
+    conn.showPagedResults(params)
+    conn.deleteTodo(todo.getId)
+    echo("Deleted rows for id 3? ")
+    let res = conn.deleteTodo(todo.getId)
+    echo("Deleted rows for id 3? " & $res)
+    if todo.update(conn):
+      echo("Later priority $1, done $2" % [$todo.priority, $todo.isDone])
+    else:
+      echo("Can't update object $1 from db!" % $todo.getId)
+
+    # Try to list content in a different way.
+    params.pageSize = 5
+    params.priorityAscending = true
+    params.dateAscending = true
+    params.showChecked = true
+    conn.showPagedResults(params)
+  finally:
+    conn.close
+    echo("Database closed")
+
+
+# Code that will be run only on the commandline.
+when isMainModule:
+  dumTest()