From 650d2515be2756453d112c40bf81a4007f083d04 Mon Sep 17 00:00:00 2001
From: Madeorsk <madeorsk@protonmail.com>
Date: Thu, 17 Oct 2024 19:08:39 +0200
Subject: [PATCH] Add generic helper functions for models which have the same
 table definition.

---
 src/helpers.zig     | 29 +++++++++++++++++++++++++++++
 src/root.zig        |  2 ++
 tests/composite.zig |  4 ++--
 3 files changed, 33 insertions(+), 2 deletions(-)
 create mode 100644 src/helpers.zig

diff --git a/src/helpers.zig b/src/helpers.zig
new file mode 100644
index 0000000..3167db1
--- /dev/null
+++ b/src/helpers.zig
@@ -0,0 +1,29 @@
+const std = @import("std");
+
+/// Simple ModelFromSql and ModelToSql functions for models which have the same table definition.
+pub fn TableModel(comptime Model: type, comptime TableShape: type) type {
+	// Get fields of the model, which must be the same as the table shape.
+	const fields = std.meta.fields(Model);
+
+	return struct {
+		/// Simply copy all fields from model to table.
+		pub fn copyModelToTable(_model: Model) !TableShape {
+			var _table: TableShape = undefined;
+			inline for (fields) |modelField| {
+				// Copy each field of the model to the table.
+				@field(_table, modelField.name) = @field(_model, modelField.name);
+			}
+			return _table;
+		}
+
+		/// Simply copy all fields from table to model.
+		pub fn copyTableToModel(_table: TableShape) !Model {
+			var _model: Model = undefined;
+			inline for (fields) |tableField| {
+				// Copy each field of the table to the model.
+				@field(_model, tableField.name) = @field(_table, tableField.name);
+			}
+			return _model;
+		}
+	};
+}
diff --git a/src/root.zig b/src/root.zig
index ba51afe..12e42c0 100644
--- a/src/root.zig
+++ b/src/root.zig
@@ -17,3 +17,5 @@ pub const SqlParams = _sql.SqlParams;
 pub const conditions = @import("conditions.zig");
 
 pub const errors = @import("errors.zig");
+
+pub const helpers = @import("helpers.zig");
diff --git a/tests/composite.zig b/tests/composite.zig
index c1c316a..f5479f8 100644
--- a/tests/composite.zig
+++ b/tests/composite.zig
@@ -66,8 +66,8 @@ const CompositeModelRepository = zrm.Repository(CompositeModel, CompositeModelTa
 
 	.key = &[_][]const u8{"firstcol", "secondcol"},
 
-	.fromSql = &modelFromSql,
-	.toSql = &modelToSql,
+	.fromSql = &zrm.helpers.TableModel(CompositeModel, CompositeModelTable).copyTableToModel,
+	.toSql = &zrm.helpers.TableModel(CompositeModel, CompositeModelTable).copyModelToTable,
 });