I am quite new to programming and today decided to attempt and create a node.js and puppeteer project with the purpose of scraping website into a .txt file. I ran into issues straight away since for the most part I have no idea what I'm doing. After installing node.js and puppeteer, I was guided by some videos and articles I found to create my first project. In the command prompt using mkdir and later cd I was able to create and access the new directory, but I started running into problems with npm init. It only places the file package.json in the repository, but there isn't a package-lock or node_modules file anywhere. No idea what they do but thought this was a problem. When I open cmd and try to run the app by typing node app.js it returns Error: Cannot find module 'C:\Users\emili\app.js' along with some other gobble. What should I do, to be able to run the simple application I wrote?
It seems that you are missing some key knowledge on how NodeJS works, but in order to fix your issue (for now), you will need to take a few steps.
First, in your working directory (where the package.json is), you'll need to install your modules.
Run npm install puppeteer. This will do two things, create the node_modules folder and create the package-lock.json file.
Create a file named app.js (either manually or by running the command touch app.js) in your working directory, and put the following content inside of it:
console.log('Hello, World!');
Save the changes to app.js and then run node app.js in your terminal. You should see Hello, World! output to the terminal.
The reason npm install puppeteer created the node_modules folder and the package-lock.json file is because they weren't needed beforehand.
When you run npm install PACKAGE_NAME, you're installing a module (otherwise known as a package), thus it creates the node_modules folder so that it will have a place to put the module so that your code can access it. It also creates the package-lock.json file, which is used to track the module versions inside of your project.
With this information, I request you go back to the tutorial you were originally following and try going through it again and attempting to understand each of the core concepts before writing any real code.
Related
I'm working in a completely offline environment & lately, I've had to code some react applications. I wonder if there is a way to download npmjs packages manually without using the command npm install <package-name>.
For example, while I'm coding with python in the same offline env, I'm downloading everything from PyPi manually & use the .whl in my offline environment using removable devices from one online environment to the offline environment.
I'll appreciate for any help or direction to the solution.
You need to download their source from the github. Find the main file and then include it in your main file.
You need to find the source and go through the package.json file. There you can find which is the main file. So that you can include that in your application.
To include example.js in your app. Copy it into your application folder.
Once you do that, your requirements will just be:
var moduleName = require("path/to/example.js")
It will always look for a node_modules directory at the root of your app (and a few other places as well).
It's important you download the full repo and not just the lib folder if you plan to use it this way since the package.json file is used to find the main entry point. As long as the repository has a valid package.json file it should work.[
I have downloaded some nodejs script and there is no package.json inside. It works with a lot of npm_modules but this directory is huge and I'm pretty sure it does not use ALL of them.
Is there a way I can list all dependencies ACTUALLY used by this node script ?
in nodejs itself.
Create a simple package.json for your script (without any dependencies). After that you can npm module dependency-check (https://www.npmjs.com/package/dependency-check) with the --missing option.
Hope this helps.
Always feel stupid asking here because people are always confused with my questions, or I have a dumb problem, but, I'm working on a program in node.js and the text editor I'm using (NP++) doesn't seem to like to save files in the system32 directoy, (The directory where my modules are), and that is where my script is as well. (So I have .../.../node_modules/(modules) and .../.../node_modules/script.js) this becomes a pain when I want to edit the script, I have to clone the script to my desktop, then edit it, then overwrite the one in the node_modules directory. I tried saving the script to my desktop and running it, but it just gives me an error of module not found. (In my script I have the modules as var example = require('example.js')) Is there any way I can get it to get the modules from the node_modules directory, while keeping the script file somewhere easily accessible and editable? (i.e desktop?) (Sorry if this is confusing, not the best at these kind of things)
I'm not 100% sure that this is what's happening because I haven't used npm on Windows, but it sounds to me like you're installing your dependencies globally using npm -g. The more proper way to use Node is to install your dependencies locally, using npm without the -g flag. That way your dependencies get installed in your current working directory.
For example, let's say you've saved your project in a directory on your Desktop, and your script uses require("lodash"). If you cd to your directory and run npm install lodash, then the lodash module will be available to your script.
I am a beginner to mean.
I have followed the following steps to create meanjs app :
installed node v0.12.7
npm install -g bower
npm install -g grunt-cli
npm install -g yo
npm install -g generator-meanjs
cd C:\Users\SHIVAM\Desktop\MyApp
yo meanjs
MyApp folder containing mean directory created
Error occured on yo meanjs 1
Please provide a solution . I am struck at the first phase. I need to get started as sson as possible .
Version 0.4.* has different folder structure. The tutorial you are following is probably using earlier version of meanjs. You can find the new structure here-http://www.bossable.com/954/version-0-4-0/ She has compared the structure with the older one. I was going through the same problem. Follow these tutorials, it will be of great help.
The following directories have been changed in the 0.4.* versions of Meanjs; 0.4.2 is still unstable. 0.4.0 and 0.4.1 is recommended for beginners to get on MEAN.
-New files have been added
1) gulpfile.js-Gulp is relatively faster than grunt because gulp focuses on code rather than cofiguration. It uses node.js’ streams, and executes faster, since it does not open/close files, or create intermediary copies all the time. The lack of any up-front configuration, especially, specifying a source and destination is noticed immediately in this file.
2) protractor.conf.js-Support file for end-to-end testing in angularjs applications. (Pretty Neat.)
The app folder is removed, which is the major concern for the noobs trying their hands on MEANjs following the older tutorials. Controllers,views, models are now moved into a separate folder called modules which was previously in the public folder.
You can explore modules/core/server and modules/user/server of your project
Addition of client, server and test in modules/core and modules/user folder. All the client side angular will now be in the modules/core/client making it easier to access all services and directives of different modules of the application at one place. And all the backend or server-side files goes to modules/core/server.
public/application.js and public/config.js are now config.js and init.js in modules/core/client/app folder.
config folder is split and new folders assets and lib are added.
The previous env folder have been split into env and assets. All the references, mongodb port, session keys goes to the environment(env) whereas new libraries we are defining into our project goes to assets. For instance new css, sass or less reference will be defined into asset/default.js. config.js and init.js are merged into one file config/config.js.
lib contains express.js, mongoose.js and socket.io.js.
node_modules is pretty much exactly the same as the previous versions of meanjs.
These are the major changes in the folder structure. New models and controllers are added into the modules/users/server according to your application, just so you don't get lost while developing your project.
I have a server.js file that I downloaded from someone's website. The first line is: var express=require('express');
When I try to run this server with "node server.js" I get the following error: "Cannot find module 'express'." The express module is installed in the default node install location:
C:\Users\myname\node_modules\express\
I'm able to successfully run express by executing "node express.js" from the express install location in node_modules. I also tried copying over the express folder and file into my c:\node-testing\ directory where my server.js file is located but I still get the error. Any idea what the problem might be and how to fix?
You can set the NODE_PATH environment variable to tell nodejs to search other paths for globally installed modules that are not in the project directory.
See http://nodejs.org/api/modules.html#modules_loading_from_the_global_folders for details.
On Unix installations there are some built-in default locations, but on Windows, it appears you have to set this environment variable manually to support a global location.
FYI, if you want require to load a module from the project directory, then you have to use
require("./filename");
with the ./ in front of it. That's why it didn't work when you copied it to the project directory. node makes a distinction between loading from the project directory vs. loading from the node_modules directory below and thus requires a different syntax to specify which one you want. Express.js is also not a stand-alone module because it depends on a bunch of other modules so you could not copy only it. I'd recommend using the NODE_PATH option or install express into your project directory (it will end up in a node_modules sub-directory).
Node.js will only search for modules in from the current (and parent) directories. Unlike npm, Node has no concept of "global" modules.
You need to run npm install to install your modules into the directory containing your code.