From b578ce659afefb2ad3893a0cf5c53e07d2d9a194 Mon Sep 17 00:00:00 2001
From: tactonbishop <tactonbishop@gmail.com>
Date: Thu, 4 Aug 2022 14:30:04 +0100
Subject: [PATCH] Last Sync: 2022-08-04 14:30:04

---
 .../NodeJS/REST_APIs/{2_PUT.md => 2_POST.md}  | 33 +++++++++++-
 .../NodeJS/REST_APIs/3_PUT.md                 | 52 +++++++++++++++++++
 .../NodeJS/REST_APIs/Validation.md            |  4 +-
 3 files changed, 85 insertions(+), 4 deletions(-)
 rename Programming_Languages/NodeJS/REST_APIs/{2_PUT.md => 2_POST.md} (60%)
 create mode 100644 Programming_Languages/NodeJS/REST_APIs/3_PUT.md

diff --git a/Programming_Languages/NodeJS/REST_APIs/2_PUT.md b/Programming_Languages/NodeJS/REST_APIs/2_POST.md
similarity index 60%
rename from Programming_Languages/NodeJS/REST_APIs/2_PUT.md
rename to Programming_Languages/NodeJS/REST_APIs/2_POST.md
index 7b2302f..b32b3f2 100644
--- a/Programming_Languages/NodeJS/REST_APIs/2_PUT.md
+++ b/Programming_Languages/NodeJS/REST_APIs/2_POST.md
@@ -45,7 +45,6 @@ const addCourse = async (newCourse) => {
     console.error(err);
   }
 };
-
 addCourse("Biology and Life Sciences");
 ```
 
@@ -55,4 +54,34 @@ Which returns:
 { id: 4, name: 'Biology and Life Sciences' }
 ```
 
-The `id` is added by the server, not the client. Having created the new value we add it to our `courses` array. (In reality we would be creating a new entry in a database.) Then we follow the convention of returning the new value back to the client. 
\ No newline at end of file
+The `id` is added by the server, not the client. Having created the new value we add it to our `courses` array. (In reality we would be creating a new entry in a database.) Then we follow the convention of returning the new value back to the client. 
+
+## Validation
+
+We should accept alterations to the database that are not first validated. We can use the [Joi validator](/Programming_Languages/NodeJS/REST_APIs/Validation.md) to vet the request:
+
+```js
+function validateCourse(course) {
+  const schema = Joi.object({
+    name: Joi.string().min(3).required(),
+  });
+
+  const { error } = schema.validate(course);
+  return error;
+}
+```
+We can then add the validation as part of our general error handling:
+
+```js
+app.post('/api/courses', (req, res) => {
+	const course = {
+		id: courses.length + 1,
+		name: req.body.name
+	}
+  const { error } = schema.validate(req.body);
+  if (error) return error.details.map((joiErr) => res.status(400).send(joiErr.message));
+  
+  courses.push(course);
+  res.send(course)
+})
+```
diff --git a/Programming_Languages/NodeJS/REST_APIs/3_PUT.md b/Programming_Languages/NodeJS/REST_APIs/3_PUT.md
new file mode 100644
index 0000000..f7cb955
--- /dev/null
+++ b/Programming_Languages/NodeJS/REST_APIs/3_PUT.md
@@ -0,0 +1,52 @@
+---
+tags:
+  - Programming_Languages
+  - backend
+  - node-js
+  - express
+  - REST
+  - apis
+---
+
+# Creating a REST API with Node and Express: PUT requests
+
+To demonstrate the handling of PUT requests, we will create a handler that updates an element in the course array, based on its `id` and return the updated entry:
+
+```js
+app.put("/api/courses/:id", (req, res) => {
+  const course = courses.find((c) => c.id === parseInt(req.params.id));
+
+  if (!course)
+    return res.status(404).send("A course with the given ID was not found");
+  const { error } = validateCourse(req.body);
+
+  if (error)
+    return error.details.map((joiErr) => res.status(400).send(joiErr.message));
+
+  course.name = req.body.name;
+  res.send(course);
+});
+
+```
+Our request:
+
+```js
+const updateCourse = async (courseChange) => {
+  try {
+    const resp = await axios.put("http://localhost:3000/api/courses/1", {
+      name: courseChange.name,
+    });
+    console.log(resp.data);
+  } catch (err) {
+    console.error(err);
+  }
+};
+
+updateCourse({ name: "A new course" });
+```
+
+Returns:
+
+```js
+{ id: 1, name: { name: 'A new course' } }
+```
\ No newline at end of file
diff --git a/Programming_Languages/NodeJS/REST_APIs/Validation.md b/Programming_Languages/NodeJS/REST_APIs/Validation.md
index d16acf4..705541d 100644
--- a/Programming_Languages/NodeJS/REST_APIs/Validation.md
+++ b/Programming_Languages/NodeJS/REST_APIs/Validation.md
@@ -14,14 +14,14 @@ One of the most popular schema validators for NodeJS is [joi](https://www.npmjs.
 
 Let's say we have a POST request that expects a single field as the body that must be a string and greater than two characters long. First we define our schema:
 
-````js
+```js
   const schema = Joi.object({
     name: Joi.string().min(3).required(),
   });
 
   const { error } = schema.validate(req.body);
 
-````
+```
 
 The `schema` variable is an object whose keys should match those of the intended request body. Instead of actual values we provide Joi's in-built validators, concatenated as necessary. We then store the results of the validation in a variable.