Is that possible to refresh some dependencies when a node.js application is running ?
For instance, I'm using a specific version of lodash, a new version is released, can I trigger the refresh directly from my app, or I'll add necessariliy to edit package.json and rebuild the app manually?
Just to get a few facts straight:
Once a module is loaded, the operative code lives in memory in the JS interpreter. Changing the file on disk has no affect at all.
Once a module is loaded and other modules have a reference to it, there is no systematic way to replace that module reference with a new one. You could conceivably delete the prior module from the module cache, load a new module, get a new module handle and manually tell every piece of code that was using the prior module that they should switch over to using the new module handle, but that's a lot of custom code and there are likely some caveats to making that work properly in some circumstances.
node.js does not have any built-in way to replace code with a new version of the code.
The usual way to "upgrade" your code is to replace the code with the updated code and then restart your app so it will load the new version of the code.
Is that possible to refresh some dependencies when a node.js application is running ?
So, it is technically feasible to manually delete a module from the module cache, then manually load an update version of the module and then manually tell everyone who was using the old module handle that they should switch over to the new module handle. But, this all assumes that there's no state in the original module that needs to be preserved and assumes that you have some way of giving every user of the module a new module handle. It's a big hand coded project with a lot of limitations (e.g. only works in very limited circumstances).
For instance, I'm using a specific version of lodash, a new version is released, can I trigger the refresh directly from my app or I'll add necessariliy to edit package.json and rebuild the app manually?
Replace code with updated code, restart your app. That's the usual way.
Related
I have published a global node package via npm to generate boilerplate templates for projects at my company.
I would like to compare the current version with the latest published in order to exit the process if it’s not the latest.
What node libraries would you recommend to check for the latest version.
Is there a way to auto update the global package if a new version is detected.
Remember this is an internal tool for my company so It’s critical they are creating projects with the latest templates and I’d like them to be able to update as automatically or easily as possible
Personal Suggestion
Instead of forcing the user to upgrade, another option is to publish your templates (as zip) on remote static server (e.g. S3). In such case, you can often update the zip to the latest template without upgrading the template generator.
generate-template angularjs-template:latest
generate-template angularjs-template:4.3
Answering Your Questions
What node libraries would you recommend to check for the latest version.
I am not sure if there is a library for this. However, you can build one very easily.
Create a JSON file which contains the package information (e.g. latest stable version, deprecation message, etc.).
Upload the JSON file to a remote static server.
Whenever the user runs your program, download the JSON file and check against the current package.json.
Show a deprecation warning if the user should upgrade.
process.exit() the application if the user must upgrade.
Is there a way to auto update the global package if a new version is detected.
I think it is better to leave the control to the user, because there could be some reasons why he doesn't prefer upgrade. For example, if the user has a bunch of projects started 10 months ago, he might want to use the same template for newer projects.
But if you really want to automate it, you might use the following code (not tested).
const { execSync } = require('child_process');
const pkg = require('./package.json')
execSync(`npm update -g ${pkg.name}`)
process.exit()
I'd like to require a module on a folder, as a plugin. So I want the user to be able to add JavaScript files into an already compiled electron/webpack application and having my application load and execute it. So it would be like a plugin system. I have tried requiring every file inside the plugins/ folder but it turns out that it just gets bundled into bundle.js when compiled, and I want to be able to change it after compiled, like a plugin. How can I accomplish this?
I think what you're looking for is global.require as stated in this similar question.
Note that as it's Node's require, it will cache required module, so modifying a plugin's code will not have effect until you restart your electron application so that it does call global.require again. If that is an issue, you can force-reload a specific module with this (unrecommended) snippet:
delete global.require.cache[global.require.resolve(moduleName)]
I am working on node js application and it is now ready to use. I want to make exe of this application so that it can be used for commercial usage.
Up to now I have used enclose module using which I have compiled the code of application but I have found some issues in that (app got crash on idle condition). App is running good without enclose or compiled code.
I have searched on google and found some alternate modules like JXcore, Node webkit and Electron etc. but JX core giving error same as in SO question.
In node web-kit, it's functionality is not looking suitable as we need its executable and some dll's along with our code, which makes our package bulky.
I have also tried jxcore. The main problem with the exe's and with modules that we use is their ability to work with native modules, in my case the Kinect.node module. This module cannot be compiled. We need a workaround to package only this along with our .exe file. Enclose provides this workaround in its inbuilt functionality.
Also looking a response from EncloseJS, which is actually run by just one person who gives further instructions upon purchase. A purchase is needed for commercial usage.
In case of Electron, It is supporting only Electron-based application source code. So If I choose this then I have to modify my application code.
So can any one suggest me what can I do to make exe file from node js code there?
Thank you!
I had the same issue before, the node js application close when running in background. now i am using process manager2 (pm2), it is working fine and if the application is crash due to any other reason it is automatically started again.
I have gotten my answer:
First, reason was DiskDB database, it was not compatible with the node webkit so that is why I was getting error of native modules.
Now I am using sqlite3 module for local database. It is better than DiskDB.
Second, One reason was free version of enclose, Paid version of Enclose JS module ignores the timeout issue which I was getting.
This way I have resolved my question.
I'm trying to learn how to create and publish an npm package.
I have created an npm package, https://github.com/nitte93/OnBoarding
for my learning purpose.
https://www.npmjs.com/package/onBoarding
It works fine in dev build, but when I try to import it in my isomorphic react app, I get : ReferenceError: window is not defined
I have not made any explicit use of the window object in the package, but there are places where I have explicitly use jquery.
Now, I am not sure but all I understood was, that while importing this npm package in my isomorphic app, I'm trying to use the window object in NODE environment, which I assume is wrong since window object is only accessible on the browser side.
My question is how do I handle this.
1) Do I need to handle this in my npm package itself.
2)Should I handle it in my Isomorphic app? How?
Please answer or point to a right resource to solve this issue.
I looked through your repository, and the only thing I think could be the culprit is that the semantic-ui vendor js files are required in the OnBoarding.js component, which I assume is also a server rendered file. You need to instead require those packages that only run on the browser inside the client file (the one that will call ReactDom.render().. I think it's /src/example/index.js).
Also, as a rule of thumb don't put any browser specific code in componentWillMount, as that does get called on the server. componentDidMount is safe, though, as it's only called in the browser.
I'm writing an application using NW.js and TypeScript. I would like to use one class per file.
To access node.js modules, I need to use require(). However, the document context within a require()d module is no longer the browser's document context.
It seems to me that I need to stick to namespaces to be able to access the browser DOM from my application.
How can I combine those two module styles in one TypeScript application? When trying to use namespace together with require, my types suddenly lose visibility across files (because the compiler goes into external module mode.)
It seems to me that I need to stick to namespaces to be able to access the browser DOM from my application
No. You can use a module loader like webpack to bundle the portions that the browser needs into a single bundle.js while still keeping all your code base in commonjs mode.
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A quickstart is available : https://basarat.gitbooks.io/typescript/content/docs/quick/browser.html
More More
I am actually creating an OSS editor that demonstrates this : http://alm.tools/. The whole project (backend + server) has a single tsconfig.json file.