LAB | Basic Express Routes

Learning Goals

This exercise allows you to practice and apply the concepts and techniques taught in class.

Upon completion of this exercise, you will be able to:

Set up a Node.js project and initialize package.json
Install Express.js in a Node.js project using npm
Use the require() syntax to import modules and packages
Create a simple HTTP server using Express.js
Set up middleware in Express.js to perform additional request processing such as logging, serving static files, etc.
Implement server routes that handle GET HTTP requests

Introduction

In this lab we will practice creating a basic Node application and writing the basic routes using express. Finally we will test the routes using postman

Setup

Fork this repo
Clone this repo
Open the LAB and start

cd lab-express-basic-server

Submission

Upon completion, run the following commands:

git add .
git commit -m "done"
git push origin master

Create a Pull Request and submit your assignment

Instructions

Try your best to solve each iteration on your own before checking the solution. Nevertheless, if you find yourself stuck, feel free to check the provided solution as a reference to help you solve the iteration.

Iteration 0 | Set up the project

To set up the project, follow the below steps.

1. Initialize Node application & Install express:

Run npm init -y to create a package.json file.
Run npm install express to install the Express package.

2. Create index.js:

In the root of the project, create an index.js file
Add a console.log("test") in your index.js file and run the file to test if everything is working: node index.js

Iteration 1 | Create Express Server

Next, you should create an Express server in index.js:

Import the express package using require()
run an instance of the express package with writing the following : const app = express()

Iteration 2 | Create a new route /role-model

Think about someone you admire. Could be a celebrity, a friend, or a family member. When a request is sent to this route a response should be sent back as a JSON object.

The JSON object should look like the following:

  let roleModel = {
      name: "Margot Robbie",
      occupation: "Actor",
      languages:["English"]
    }

Iteration 3 | Listen on port 5005

At the moment when we run the index.js file the application doesn't await a request. Write the code to have the app listen on port 5005

Iteration 4 | Test the route in postman

Send a request in postman to the route we created in iteration 2. The response should be the object containing the role model information

Expected Result:

FAQs

I am stuck and don't know how to solve the problem or where to start. What should I do?

If you are stuck in your code and don't know how to solve the problem or where to start, you should take a step back and try to form a clear question about the specific issue you are facing. This will help you narrow down the problem and come up with potential solutions.

For example, is it a concept that you don't understand, or are you receiving an error message that you don't know how to fix? It is usually helpful to try to state the problem as clearly as possible, including any error messages you are receiving. This can help you communicate the issue to others and potentially get help from classmates or online resources.

Once you have a clear understanding of the problem, you will be able to start working toward the solution.

When I try to run the app, I get an error "command not found: nodemon"

Make sure you have nodemon installed on your machine:

npm install -g nodemon

This will install nodemon globally on your system, making it available to all of your projects.

I got the error: "Cannot find module" Node.js". How can I resolve it?

The error "Cannot find module" in a Node.js application means that the module you are trying to import or use does not exist in your project or cannot be found by Node.js.

There are a few things you can try to resolve the issue:

Dependencies are not installed: Make sure that all dependencies are installed.

To do this, run the command `npm install` in the root folder of your project.
This will install all of the dependencies listed in the project's `package.json` file, and ensure that all of the modules that your Node'js application requires are available.

Module is not installed: Make sure that the package you are trying to use is listed in the project's package.json and that it is installed.

To do this, run the command `npm install <package_name>`, replacing the `<package_name>` with the name of the package.
This will add the package to the list of dependencies in the `package.json` file, and install it in the project.

Module is not imported: Make sure that you've imported the module/package correctly and that the require statement is spelled correctly and available in the correct place in your code.
Wrong file path: If you are importing another file as a module, make sure that the file you are trying to require is located in the correct folder and that you are using the correct file path.
Wrong module/package name: Check the spelling of the package name you are trying to import.

My links are not working properly. Should I use a relative or an absolute path?

When linking to other pages within your Express app, as a general rule you should use relative paths that start with a forward slash /.

This way you ensure that the links will work correctly both in your development environment and when the app is deployed.

For example, instead of linking to a page with an absolute path like this:

<a href="http://yourdomain.com/contact"> Contact </a>

You should use a relative path starting with a forward slash / like this:

<a href="/contact"> Contact </a>

I got the error "Error: listen EADDRINUSE: Address already in use". How do I fix it?

This error means that the port is taken by another process that is still running on that port.

To fix the issue, you need to kill the process using the port and then run the command again. Here's how to do it:

On Mac/Linux

To kill the process running on port 3000, run the following command in the terminal:

sudo kill -9 $(lsof -t -i:3000)

Important: Replace the above example port 3000 with the port number of the process you are trying to kill.

On Windows

1. Using the Task Manager

To kill the running process on Windows using the Task Manager do the following:

Open the Task Manager by pressing: Ctrl + Shift + Esc
Find the Node process you want to terminate.
Right-click and select End Task

2. Using Command Prompt

To kill the running process on Windows using the Command Prompt do the following:

Open the windows Start menu
Search for CMD in the search bar
In the search results, right-click on Command Prompt and select Run as administrator. This will open the Command Prompt terminal.
In the Command Prompt terminal, run the following command to find the process ID:

netstat -ano|findstr "PID :3000"

If the process happens to be running on another port, simply replace 3000 with the number the port number the process is running on.

This will return the process id (PID). You should then run the following command using the process id (PID) you got in the previous step to terminate the process:

taskkill /PID 12345 /f

Important: Replace the above example PID 12345, with the process id (PID) you got in the previous step.

I got the error "Port is already in use". How do I fix it?

This error means that the port is taken by another process that is still running on that port.

To fix the issue, you need to kill the process using the port and then run the command again. Here's how to do it:

On Mac/Linux

To kill the process running on port 3000, run the following command in the terminal:

sudo kill -9 $(lsof -t -i:3000)

Important: Replace the above example port 3000 with the port number of the process you are trying to kill.

On Windows

1. Using the Task Manager

To kill the running process on Windows using the Task Manager do the following:

Open the Task Manager by pressing: Ctrl + Shift + Esc
Find the Node process you want to terminate.
Right-click and select End Task

2. Using Command Prompt

To kill the running process on Windows using the Command Prompt do the following:

Open the windows Start menu
Search for CMD in the search bar
In the search results, right-click on Command Prompt and select Run as administrator. This will open the Command Prompt terminal.
In the Command Prompt terminal, run the following command to find the process ID:

netstat -ano|findstr "PID :3000"

If the process happens to be running on another port, simply replace 3000 with the number the port number the process is running on.

This will return the process id (PID). You should then run the following command using the process id (PID) you got in the previous step to terminate the process:

taskkill /PID 12345 /f

Important: Replace the above example PID 12345, with the process id (PID) you got in the previous step.

I got the error "Refused to apply style ... ('text/html') is not a supported stylesheet MIME type". What should I do?

This error most commonly occurs when the browser attempts to load a resource (i.e., stylesheet) but the server instead returns an HTML page. For example, if there is an issue with the file path and the server is unable to serve the file, it may return a 404 HTML page.

There are a few things you should look at to troubleshoot this:

Try accessing the file directly: To verify that the server is returning an HTML page instead of the requested file, copy the file path and try to access the file directly from a new browser tab.
Check the file path: Make sure that the file path used is correct and that the file actually exists in that location. If there is a typo or error in the file path, the server will not be able to find the file.
Check the static files middleware configuration: Check that your express.static middleware, which serves static files, is correctly configured and that the right folder path and name are specified. If this middleware is not set up correctly, the server will not send the images when requested.

I am getting an error: "not defined". How do I fix it?

The "ReferenceError: variable is not defined" error in JavaScript occurs when you try to access a variable or a function that has not been defined yet or is out of scope. To fix the issue, check that you have defined the variable or function that you are trying to use and double-check the spelling to make sure you are using the correct name. In case the variable or a function is defined in another file, make sure that the file has been imported or loaded correctly.

I am unable to push changes to the repository. What should I do?

There are a couple of possible reasons why you may be unable to push changes to a Git repository:

You have not committed your changes: Before you can push your changes to the repository, you need to commit them using the git commit command. Make sure you have committed your changes and try pushing again. To do this, run the following terminal commands from the project folder:

git add .
git commit -m "Your commit message"
git push

You do not have permission to push to the repository: If you have cloned the repository directly from the main Ironhack repository without making a Fork first, you do not have write access to the repository. To check which remote repository you have cloned, run the following terminal command from the project folder:

```bash
git remote -v
```

If the link shown is the same as the main Ironhack repository, you will need to fork the repository to your GitHub account first, and then clone your fork to your local machine to be able to push the changes.

Note: You may want to make a copy of the code you have locally, to avoid losing it in the process.

mashour8/lab-intro-to-node-express

LAB | Basic Express Routes

Learning Goals

Introduction

Setup

Submission

Instructions

Iteration 0 | Set up the project

Iteration 1 | Create Express Server

Iteration 2 | Create a new route /role-model

Iteration 3 | Listen on port 5005

Iteration 4 | Test the route in postman

FAQs

On Mac/Linux

On Windows

1. Using the Task Manager

2. Using Command Prompt

On Mac/Linux

On Windows

1. Using the Task Manager

2. Using Command Prompt