model: Use only string types for models

When a HTML form is converted to JSON by JavaScript using `FormData()`,
`Object.fromEntries()` and `JSON.stringify` the data type is always
`string`. This does not match the Go struct definitions using multiple
types including e.g. `int`.

There are several options to solve this conflict:

1. use only strings in Go struct definitions
2. write custom functions to parse string-based JSONs to Go structs
3. implement custom functions in JS to use `number` type if possible

Option 3 seems to be a very clean solution. Nevertheless it is limited
by the fact that JSON anyway has a way more limited type system than Go.
So the types used in Go cannot be used and this would reduce this option
to a variant of option 2.

Option 2 requires significant effort per struct inside the model
package. Every object which is transferred via JSON and serialized into
Go structs would require a second struct definition with string types
and a conversion function. This does not scale.

Thus option 1 seems to be the best fit. The reasons for using types like
`int` or `bool` are:

- less memory consumption than `string` in most cases
- implicit data validation (e.g. enforcing positive numbers with `uint`)
- better compatibility with certain APIs which rely on e.g. `int`

The first argument is not so relevant in this use case. The amount of
required memory is still quite small for servers. Implicit data
validation is a good thing but not enough. There should anyway be
validation method which has to be called on CRUD methods and JSON
deserialization.

1 files changed, 1 insertions, 5 deletions

diff --git a/view/recipe.go b/view/recipe.go
index b0525a1..1dd6045 100644
--- a/view/recipe.go
+++ b/view/recipe.go
@@ -2,7 +2,6 @@ package view
 
 import (
 	"net/http"
-	"strconv"
 
 	"xengineering.eu/ceres/model"
 
@@ -10,11 +9,8 @@ import (
 )
 
 func Recipe(w http.ResponseWriter, r *http.Request) {
-	id_str := mux.Vars(r)[`id`]
-	id, _ := strconv.Atoi(id_str)
-
 	recipe := model.Recipe{}
-	recipe.Id = int64(id)
+	recipe.Id = mux.Vars(r)[`id`]
 
 	err := recipe.Read()
 	if err != nil {