Traverse – very useful npm package

NPM has a lot, a lot of useful packages… and a lot of useless packages of course. Sometimes we can find something very nice. Last time I must modified nested object in JavaScript. I can write my own function to do this, use recursion for example, but I simply… didn’t have enough time to do this. I must find solution quickly, good solution. I and found – it’s traverse package. Yes, its name is very meaningful.

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Arrow functions in JavaScript

One of very, very nice ES6 capabilities are arrow functions. Using them, we can creae shorter, cleaner code, and also avoid important issues with this keyword – I wrote about this keyword in one of some ealier posts. This time I would like to write few sentences about arrow functions. If you do not know them yet, you should get to know them as soon as possible.

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Phantom.js – use custom fonts in HTML to PDF convert

Very short, but I think, may help a lot of people… Last time I spent a lot of time on the big issue with Phantom.js in Node app. Very common task: application should generate PDF files from input HTML code. Nothing difficult, yes? Yep, and it worked fine on my Node app… But one day, client said, that we should change font in document. Simple, we can just use font-face in input HTML styles, right? In theory, yes. Phantom.js and Node packages to use this library to convert HTML to PDF can use custom fonts and also other external assets like images.

With very popular html-pdf package we can use external, full link to assets, use absolute path to our local directory with files (using file:/// prefix) or specify base path in rendering options, and then use relative (to this base path) paths in our styles. And… it works fine. It also worked fine with custom fonts on my project. But only on local machine where I use MacOS. After deploying app to Debin, Ubuntu Server or CentOS server, PDFs are broken – with no selected text, but all pages are “images”, with many broken characters and very big results file (it isn’t strange if we have images, instead of text in PDF). Custom fonts have been used correctly, but PDF was broken, why?

It’s library and Phantom.js issue, but solution is very, very simple. We must install our custom fonts locally on production machine and do not attach them in CSS – just use as existing font-family! It’s because Phantom is external script and it can use system-wide fonts. Where should we place our files? There are directories. If you have issues with custom fonts and non-selectable text, just copy fonts to:

/usr/share/fonts
/usr/local/share/fonts/

Nconf – simple, great solution for Node.js app configuration

When I started work with Node.js and Express, I was looking for something to store my app settings. Something like env files in many PHP frameworks – central place for configuration, not stored in repository, but only for example when we run app in development or production environment. We can write custom code for that, or use some modules from npm, also directly for env files. Nuxt package also has dedicated env file module. These modules are great, but there is something much, much better – nconf.

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Run Node.js app on Ubuntu Server using pm2

I work with Node.js and some other JavaScript technologies in last months. One important think is – how run ready application on production server? It wasn’t easy question, because earlier I used only development mode in IDE (with automatic rebuild and generation in background). After some research I found pm2 – great package to run Node.js application in background. With that manager we can start, stop or restart many applications. Let’s see how we can easily run Node.js app.

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