Expanded guides for some APIs and Microservices challenges and fixed links to the source files

guide/english/certifications/apis-and-microservices/basic-node-and-express/chain-middleware-to-create-a-time-server/index.md

@@ -5,20 +5,49 @@ title: Chain Middleware to Create a Time Server
 
 <!-- The article goes here, in GitHub-flavored Markdown. Feel free to add YouTube videos, images, and CodePen/JSBin embeds  -->
 
-Similar to the last challenge, but now we are chaining 2 functions together. It seems complicated, but it's just javascript.
+Similar to the last challenge, but now we are chaining 2 functions together. It seems complicated, but it's just JavaScript.
 
-Instead of responding with the time we can also add a string to the request and pass it to the next function. This is trivial, but it makes for a decent example. The code looks like:
+### Hint
+
+Instead of responding with the time we can also add any arbitrary property to the request object and pass it to the next function by calling the `next()` method. This is trivial, but it makes for a decent example. The code will looks like this:
 
 ```javascript
-app.get("/now", middleware(req, res, next) {
+app.get("/now", (req, res, next) => {
+  // adding a new property to req object
+  // in the middleware function
   req.string = "example";
   next();
-},
-  function (req, res) {
-      res.send(req.string); // This will display "example" to the user
+}, (req, res) => {
+  // accessing the newly added property
+  // in the main function
+  res.send(req.string);
+});
+```
+
+### Solution
+
+```javascript
+app.get("/now", (req, res, next) => {
+  req.time = new Date().toString();
+  next();
+}, (req, res) => {
+  res.send({
+    time: req.time
   });
+});
 ```
 
+You can also declare the middleware beforehand to use in multiple routes as shown below:
 
+```javascript
+const middleware = (req, res, next) => {
+  req.time = new Date().toString();
+  next();
+};
 
-<a href='https://github.com/freecodecamp/guides/tree/master/src/pages/certifications/apis-and-microservices/basic-node-and-express/chain-middleware-to-create-a-time-server/index.md' target='_blank' rel='nofollow'>Help our community expand these hints and guides</a>.
+app.get("/now", middleware, (req, res) => {
+  res.send({
+    time: req.time
+  });
+});
+```

guide/english/certifications/apis-and-microservices/basic-node-and-express/get-query-parameter-input-from-the-client/index.md

@@ -5,16 +5,19 @@ title: Get Query Parameter Input from the Client
 
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-Given the hint after the stub, "/name?first=<firstname>&last=<lastname>," we can build the response like so:
+Given the endpoint URL, `/name?first=firstname&last=lastname`, we can extract the query parameters (`first` and `last`) and their corresponding values from the `req.query` object and send a custom JSON response containing values derived from the query parameters to the client.
+
+### Solution
 
 ```javascript
- app.get("/name", function(req, res) {
-   var firstName = req.query.first;
-   var lastName = req.query.last;
-   // Send the json object
- });
+app.get("/name", function(req, res) {
+  var firstName = req.query.first;
+  var lastName = req.query.last;
+  // OR you can destructure and rename the keys
+  var { first: firstName, last: lastName } = req.query;
+  // Use template literals to form a formatted string
+  res.json({
+    name: `${firstName} ${lastName}`
+  });
+});
 ```
-
-
-
-<a href='https://github.com/freecodecamp/guides/tree/master/src/pages/certifications/apis-and-microservices/basic-node-and-express/get-query-parameter-input-from-the-client/index.md' target='_blank' rel='nofollow'>Help our community expand these hints and guides</a>.

guide/english/certifications/apis-and-microservices/basic-node-and-express/get-route-parameter-input-from-the-client/index.md

@@ -5,17 +5,31 @@ title: Get Route Parameter Input from the Client
 
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-If someone tells you to build a GET or POST you would do app.get(...) or app.post(...) accordingly. The basic structure of the challenge is:
+If someone tells you to build a GET or POST endpoint you would achieve the same using `app.get(...)` or `app.post(...)` accordingly.
+
+## Hint
+
+In order to get route parameters from a POST request, the general format is as follows:
 
 ```javascript
-app.get("/:word/echo", function(req, res) {
-  // word = req.params.word;
-  // respond with the json object
+app.post("/:param1/:param2", (req, res) => {
+  // Access the corresponding key in the req.params
+  // object as defined in the endpoint
+  var param1 = req.params.parameter1;
+  // OR use destructuring to get multiple paramters
+  var { param1, param2 } = req.params;
+  // Send the req.params object as a JSON Response
+  res.json(req.params);
 });
 ```
 
+## Solution
 
-
-
-
-<a href='https://github.com/freecodecamp/guides/tree/master/src/pages/certifications/apis-and-microservices/basic-node-and-express/get-route-parameter-input-from-the-client/index.md' target='_blank' rel='nofollow'>Help our community expand these hints and guides</a>.
+```javascript
+app.get("/:word/echo", (req, res) => {
+  const { word } = req.params;
+  res.json({
+    echo: word
+  });
+});
+```

guide/english/certifications/apis-and-microservices/basic-node-and-express/implement-a-root-level-request-logger-middleware/index.md

@@ -24,8 +24,5 @@ If you have trouble formatting the string correctly, one way to do it looks like
   var string = req.method + ' ' + req.path + ' - ' + req.ip;
 ```
 
-
-<a href='https://github.com/freecodecamp/guides/tree/master/src/pages/certifications/apis-and-microservices/basic-node-and-express/implement-a-root-level-request-logger-middleware/index.md' target='_blank' rel='nofollow'>Help our community expand these hints and guides</a>.
-
 ### Resources
 - [Express Middleware](https://expressjs.com/en/guide/using-middleware.html)

guide/english/certifications/apis-and-microservices/basic-node-and-express/serve-an-html-file/index.md

@@ -16,8 +16,3 @@ To serve an index.html in a folder called "public" at the root domain you would
 ```
 
 Note: __dirname returns the root directory is a best practice for node developers.
-
-
-
-
-<a href='https://github.com/freecodecamp/guides/tree/master/src/pages/certifications/apis-and-microservices/basic-node-and-express/serve-an-html-file/index.md' target='_blank' rel='nofollow'>Help our community expand these hints and guides</a>.

guide/english/certifications/apis-and-microservices/basic-node-and-express/serve-json-on-a-specific-route/index.md

@@ -5,16 +5,12 @@ title: Serve JSON on a Specific Route
 
 <!-- The article goes here, in GitHub-flavored Markdown. Feel free to add YouTube videos, images, and CodePen/JSBin embeds  -->
 
-It is rather simple to serve a json object with node (at the '/json' route), if we want to deliver a message and give it the value "Hello World," we can do so like this:
+It is rather simple to serve a JSON object with Node (at the `/json` route), if we want to deliver an object containing a key `message` and with the value `"Hello json"` we can do so as indicated:
 
 ```javascript
-  app.get("/json", function(req, res) {
-        res.json({"message": "Hello World"});
-  });
+app.get("/json", (req, res) => {
+    res.json({
+      "message": "Hello json"
+    });
+});
 ```
-
-
-
-
-
-<a href='https://github.com/freecodecamp/guides/tree/master/src/pages/certifications/apis-and-microservices/basic-node-and-express/serve-json-on-a-specific-route/index.md' target='_blank' rel='nofollow'>Help our community expand these hints and guides</a>.

guide/english/certifications/apis-and-microservices/basic-node-and-express/serve-static-assets/index.md

@@ -5,19 +5,18 @@ title: Serve Static Assets
 
 <!-- The article goes here, in GitHub-flavored Markdown. Feel free to add YouTube videos, images, and CodePen/JSBin embeds  -->
 
-Static webpages are fairly simple with express. This could be useful for building your own portfolio website or blog, etc.
-
-To serve a static webpage from the "views" folder you can use code such as:
-
-```javascript
- const express = require("express");
- const app = express();
- app.use(express.static(__dirname + "/views"));
-```
-
+Serving static webpages and assets is fairly simple with `express`. This could be useful for building your own portfolio website or blog, single-page web applications etc.
 
+To serve static assets from the `public` folder in the  you can use the `express.static()` method as the middleware. This method takes the endpoint and the absolute path to the directory containing the static assets as arguments and exposes the files in that folder at the given endpoint. By default, if the endpoint is not passed to the method, the folder is exposed at the root endpoint i.e. `/` for the application.
 
+The `__dirname` variable is a string containing the absolute path to the root of your project which has to be concatenated with the folder containing the assets.
 
+Add the following line to your file above all defined routes to achieve the desired result:
 
+```javascript
+// Normal usage
+app.use(express.static(__dirname + "/public"));
 
-<a href='https://github.com/freecodecamp/guides/tree/master/src/pages/certifications/apis-and-microservices/basic-node-and-express/meet-the-node-console/index.md' target='_blank' rel='nofollow'>Help our community expand these hints and guides</a>.
+// Assets at the /assets route
+app.use("/assets", express.static(__dirname + "/public"));
+```

guide/english/certifications/apis-and-microservices/basic-node-and-express/start-a-working-express-server/index.md

@@ -3,28 +3,20 @@ title: Start a Working Express Server
 ---
 ## Start a Working Express Server
 
-
 <!-- The article goes here, in GitHub-flavored Markdown. Feel free to add YouTube videos, images, and CodePen/JSBin embeds  -->
 
-If you had a website at "example.com/" and wanted to serve a string such as "Hello World" to whoever visits the root domain you could do so easily using node and/or express:
+If you had a website at "example.com/" and wanted to serve a string such as "Hello Express" to whoever visits the root domain you could do so easily using Node and/or express:
 
 ```javascript
 app.get("/", function(req, res) {
-  res.send("Hello World");
+  res.send("Hello Express");
 });
-
 ```
 
-
-Also, with ES6+ you can save some typing by using "=>" instead of "function," which looks like:
+Also, with the modern ES6 syntax you can save a few keystrokes by using arrow functions:
 
 ```javascript
 app.get("/", (req, res) => {
-  res.send("Hello World");
+  res.send("Hello Express");
 });
-
 ```
-
-
-
-<a href='https://github.com/freecodecamp/guides/tree/master/src/pages/certifications/apis-and-microservices/basic-node-and-express/start-a-working-express-server/index.md' target='_blank' rel='nofollow'>Help our community expand these hints and guides</a>.

guide/english/certifications/apis-and-microservices/basic-node-and-express/use-body-parser-to-parse-post-requests/index.md

@@ -4,20 +4,39 @@ title: Use body-parser to Parse POST Requests
 ## Use body-parser to Parse POST Requests
 
 <!-- The article goes here, in GitHub-flavored Markdown. Feel free to add YouTube videos, images, and CodePen/JSBin embeds  -->
+
 The body-parser should already be added to your project if you used the provided boilerplate, but if not it should be there as:
 
 ```json
 "dependencies": {
-    "body-parser": "^1.4.3",
+    "body-parser": "^1.19.0",
     ...
+    "express": "^4.17.1"
+}
 ```
 
-All you need to do for this challenge is pass the middleware to app.use(). Make sure it comes before the paths it needs to be used on. Remember that body-parser returns with `bodyParser.urlencoded({extended: false})`. Use the following as a template:
+You can run `npm install body-parser` to add it as a dependency to your project instead of manually adding it to the `package.json` file.
+
+This guide assumes you have imported the `body-parser` module into your file as `bodyParser`.
+
+In order to import the same, you just need to add the following line at the top of your file:
+
+```javascript
+var bodyParser = require('body-parser');
+```
+
+All you need to do for this challenge is pass the middleware to `app.use()`. Make sure it comes before the paths it needs to be used on. Remember that body-parser returns with `bodyParser.urlencoded({extended: false})`. Use the following as a template:
 
 ```javascript
-//app.use(middleware-function);
 app.use(bodyParser.urlencoded({ extended: false }));
+```
+
+In order to parse JSON data sent in the POST request, use `bodyParser.json()` as the middleware as shown below:
 
+```javascript
+app.use(bodyParser.json());
 ```
 
-<a href='https://github.com/freecodecamp/guides/tree/master/src/pages/certifications/apis-and-microservices/basic-node-and-express/use-body-parser-to-parse-post-requests/index.md' target='_blank' rel='nofollow'>Help our community expand these hints and guides</a>.
+The data received in the request is available in the `req.body` object.
+
+Do not forget that all these statements need to go above any routes that might have been defined.

guide/english/certifications/apis-and-microservices/basic-node-and-express/use-the-.env-file/index.md

@@ -22,9 +22,3 @@ All we need to do now is check what the value of the environment variable is, wh
    }
   });
 ```
-
-
-
-
-
-<a href='https://github.com/freecodecamp/guides/tree/master/src/pages/certifications/apis-and-microservices/basic-node-and-express/use-the-.env-file/index.md' target='_blank' rel='nofollow'>Help our community expand these hints and guides</a>.

guide/english/certifications/apis-and-microservices/managing-packages-with-npm/add-a-version-to-your-package.json/index.md

@@ -10,4 +10,4 @@ You should go over to the package.json file in your project. Versions follow a s
 "version": "x.x.x"
 ```
 
-<a href='https://github.com/freeCodeCamp/freeCodeCamp/blob/master/guide/english/certifications/apis-and-microservices/managing-packages-with-npm/add-a-version-to-your-package.json/index.md' target='_blank' rel='nofollow'>Help our community expand these hints and guides</a>.
+This convention is also known as _**semantic versioning**_ where the versions follow the format `MAJOR.MINOR.PATCH` whenever a new release is made.

guide/english/certifications/apis-and-microservices/managing-packages-with-npm/expand-your-project-with-external-packages-from-npm/index.md

@@ -4,14 +4,14 @@ title: Expand Your Project with External Packages from npm
 ## Expand Your Project with External Packages from npm
 
 <!-- The article goes here, in GitHub-flavored Markdown. Feel free to add YouTube videos, images, and CodePen/JSBin embeds  -->
-You should go over to the `package.json` file in your project. Dependencies follow a similar convention as this:
+
+The `package.json` file in the root directory of your project, among other things, lists all the dependencies that your project needs in order to work, are listed under the `dependencies` key in that file and follow a similar convention as given below:
 
 ```json
 "dependencies": {
     "express": "^4.16.4",
     "helmet": "^3.14.0"
   },
-  ...
 ```
 
-<a href='https://github.com/freecodecamp/guides/tree/master/src/pages/certifications/apis-and-microservices/managing-packages-with-npm/expand-your-project-with-external-packages-from-npm/index.md' target='_blank' rel='nofollow'>Help our community expand it</a>.
+There might be additional peer dependencies or development dependencies that your project might need in case it has to be built or compiled due to a number of reasons currently outside the scope of this challenge. They are listed under the `peerDependecies` and `devDependencies` respectively.