1677680638
https://www.youtube.com/watch?v=fbvb_52sTq0&list=PLIGDNOJWiL1-G2nGxKF1p9iHYzURKj27q&index=1
1632537859
Not babashka. Node.js babashka!?
Ad-hoc CLJS scripting on Node.js.
Experimental. Please report issues here.
Nbb's main goal is to make it easy to get started with ad hoc CLJS scripting on Node.js.
Additional goals and features are:
Nbb requires Node.js v12 or newer.
CLJS code is evaluated through SCI, the same interpreter that powers babashka. Because SCI works with advanced compilation, the bundle size, especially when combined with other dependencies, is smaller than what you get with self-hosted CLJS. That makes startup faster. The trade-off is that execution is less performant and that only a subset of CLJS is available (e.g. no deftype, yet).
Install nbb
from NPM:
$ npm install nbb -g
Omit -g
for a local install.
Try out an expression:
$ nbb -e '(+ 1 2 3)'
6
And then install some other NPM libraries to use in the script. E.g.:
$ npm install csv-parse shelljs zx
Create a script which uses the NPM libraries:
(ns script
(:require ["csv-parse/lib/sync$default" :as csv-parse]
["fs" :as fs]
["path" :as path]
["shelljs$default" :as sh]
["term-size$default" :as term-size]
["zx$default" :as zx]
["zx$fs" :as zxfs]
[nbb.core :refer [*file*]]))
(prn (path/resolve "."))
(prn (term-size))
(println (count (str (fs/readFileSync *file*))))
(prn (sh/ls "."))
(prn (csv-parse "foo,bar"))
(prn (zxfs/existsSync *file*))
(zx/$ #js ["ls"])
Call the script:
$ nbb script.cljs
"/private/tmp/test-script"
#js {:columns 216, :rows 47}
510
#js ["node_modules" "package-lock.json" "package.json" "script.cljs"]
#js [#js ["foo" "bar"]]
true
$ ls
node_modules
package-lock.json
package.json
script.cljs
Nbb has first class support for macros: you can define them right inside your .cljs
file, like you are used to from JVM Clojure. Consider the plet
macro to make working with promises more palatable:
(defmacro plet
[bindings & body]
(let [binding-pairs (reverse (partition 2 bindings))
body (cons 'do body)]
(reduce (fn [body [sym expr]]
(let [expr (list '.resolve 'js/Promise expr)]
(list '.then expr (list 'clojure.core/fn (vector sym)
body))))
body
binding-pairs)))
Using this macro we can look async code more like sync code. Consider this puppeteer example:
(-> (.launch puppeteer)
(.then (fn [browser]
(-> (.newPage browser)
(.then (fn [page]
(-> (.goto page "https://clojure.org")
(.then #(.screenshot page #js{:path "screenshot.png"}))
(.catch #(js/console.log %))
(.then #(.close browser)))))))))
Using plet
this becomes:
(plet [browser (.launch puppeteer)
page (.newPage browser)
_ (.goto page "https://clojure.org")
_ (-> (.screenshot page #js{:path "screenshot.png"})
(.catch #(js/console.log %)))]
(.close browser))
See the puppeteer example for the full code.
Since v0.0.36, nbb includes promesa which is a library to deal with promises. The above plet
macro is similar to promesa.core/let
.
$ time nbb -e '(+ 1 2 3)'
6
nbb -e '(+ 1 2 3)' 0.17s user 0.02s system 109% cpu 0.168 total
The baseline startup time for a script is about 170ms seconds on my laptop. When invoked via npx
this adds another 300ms or so, so for faster startup, either use a globally installed nbb
or use $(npm bin)/nbb script.cljs
to bypass npx
.
Nbb does not depend on any NPM dependencies. All NPM libraries loaded by a script are resolved relative to that script. When using the Reagent module, React is resolved in the same way as any other NPM library.
To load .cljs
files from local paths or dependencies, you can use the --classpath
argument. The current dir is added to the classpath automatically. So if there is a file foo/bar.cljs
relative to your current dir, then you can load it via (:require [foo.bar :as fb])
. Note that nbb
uses the same naming conventions for namespaces and directories as other Clojure tools: foo-bar
in the namespace name becomes foo_bar
in the directory name.
To load dependencies from the Clojure ecosystem, you can use the Clojure CLI or babashka to download them and produce a classpath:
$ classpath="$(clojure -A:nbb -Spath -Sdeps '{:aliases {:nbb {:replace-deps {com.github.seancorfield/honeysql {:git/tag "v2.0.0-rc5" :git/sha "01c3a55"}}}}}')"
and then feed it to the --classpath
argument:
$ nbb --classpath "$classpath" -e "(require '[honey.sql :as sql]) (sql/format {:select :foo :from :bar :where [:= :baz 2]})"
["SELECT foo FROM bar WHERE baz = ?" 2]
Currently nbb
only reads from directories, not jar files, so you are encouraged to use git libs. Support for .jar
files will be added later.
The name of the file that is currently being executed is available via nbb.core/*file*
or on the metadata of vars:
(ns foo
(:require [nbb.core :refer [*file*]]))
(prn *file*) ;; "/private/tmp/foo.cljs"
(defn f [])
(prn (:file (meta #'f))) ;; "/private/tmp/foo.cljs"
Nbb includes reagent.core
which will be lazily loaded when required. You can use this together with ink to create a TUI application:
$ npm install ink
ink-demo.cljs
:
(ns ink-demo
(:require ["ink" :refer [render Text]]
[reagent.core :as r]))
(defonce state (r/atom 0))
(doseq [n (range 1 11)]
(js/setTimeout #(swap! state inc) (* n 500)))
(defn hello []
[:> Text {:color "green"} "Hello, world! " @state])
(render (r/as-element [hello]))
Working with callbacks and promises can become tedious. Since nbb v0.0.36 the promesa.core
namespace is included with the let
and do!
macros. An example:
(ns prom
(:require [promesa.core :as p]))
(defn sleep [ms]
(js/Promise.
(fn [resolve _]
(js/setTimeout resolve ms))))
(defn do-stuff
[]
(p/do!
(println "Doing stuff which takes a while")
(sleep 1000)
1))
(p/let [a (do-stuff)
b (inc a)
c (do-stuff)
d (+ b c)]
(prn d))
$ nbb prom.cljs
Doing stuff which takes a while
Doing stuff which takes a while
3
Also see API docs.
Since nbb v0.0.75 applied-science/js-interop is available:
(ns example
(:require [applied-science.js-interop :as j]))
(def o (j/lit {:a 1 :b 2 :c {:d 1}}))
(prn (j/select-keys o [:a :b])) ;; #js {:a 1, :b 2}
(prn (j/get-in o [:c :d])) ;; 1
Most of this library is supported in nbb, except the following:
:syms
.-x
notation. In nbb, you must use keywords.See the example of what is currently supported.
See the examples directory for small examples.
Also check out these projects built with nbb:
See API documentation.
See this gist on how to convert an nbb script or project to shadow-cljs.
Prequisites:
To build:
bb release
Run bb tasks
for more project-related tasks.
Download Details:
Author: borkdude
Download Link: Download The Source Code
Official Website: https://github.com/borkdude/nbb
License: EPL-1.0
#node #javascript
1625751960
In this video, I wanted to touch upon the functionality of adding Chapters inside a Course. The idea was to not think much and start the development and pick up things as they come.
There are places where I get stuck and trying to find answers to it up doing what every developer does - Google and get help. I hope this will help you understand the flow and also how developers debug while doing development.
App url: https://video-reviews.vercel.app
Github code links below:
Next JS App: https://github.com/amitavroy/video-reviews
Laravel API: https://github.com/amitavdevzone/video-review-api
You can find me on:
Twitter: https://twitter.com/amitavroy7
Discord: https://discord.gg/Em4nuvQk
#next js #api #react next js #next #frontend #development
1625674200
In this video, we are going to implement Google Analytics to our Next JS application. Tracking page views of an application is very important.
Google analytics will allow us to track analytics information.
Frontend: https://github.com/amitavroy/video-reviews
API: https://github.com/amitavdevzone/video-review-api
App link: https://video-reviews.vercel.app
You can find me on:
Twitter: https://twitter.com/amitavroy7
Discord: https://discord.gg/Em4nuvQk
#next js #js #react js #react #next #google analytics
1598684574
Create a new web app or revamp your existing website?
Every existing website or a web application that we see with an interactive and user-friendly interface are from Front-End developers who ensure that all visual effects come into existence. Hence, to build a visually appealing web app front-end development is required.
At HourlyDeveloper.io, you can Hire FrontEnd Developers as we have been actively working on new frontend development as well as frontend re-engineering projects from older technologies to newer.
Consult with experts: https://bit.ly/2YLhmFZ
#hire frontend developers #frontend developers #frontend development company #frontend development services #frontend development #frontend
1600210920
Micro-frontends are the future of frontend web development. Inspired by microservices, which allow you to break up your backend into smaller pieces, micro-frontends allow you to build, test, and deploy pieces of your frontend app independently of each other. Depending on the micro-frontend framework you choose, you can even have multiple micro-frontend apps – written in React, Angular, Vue, or anything else – coexisting peacefully together in the same larger app!
In this article, we’re going to develop an app composed of micro-frontends using single-spa and deploy it to Heroku. We’ll set up continuous integration using Travis CI. Each CI pipeline will bundle the JavaScript for a micro-frontend app and then upload the resulting build artifacts to AWS S3. Finally, we’ll make an update to one of the micro-frontend apps and see how it can be deployed to production independently of the other micro-frontend apps.
Demo app - end result
Before we discuss the step-by-step instructions, let’s get a quick overview of what makes up the demo app. This app is composed of four sub-apps:
These four apps all live in separate repos, available on GitHub, which I’ve linked to above.
The end result is fairly simple in terms of the user interface, but, to be clear, the user interface isn’t the point here. If you’re following along on your own machine, by the end of this article you too will have all the underlying infrastructure necessary to get started with your own micro-frontend app!
Alright, grab your scuba gear, because it’s time to dive in!
To generate the apps for this demo, we’re going to use a command-line interface (CLI) tool called create-single-spa. The version of create-single-spa at the time of writing is 1.10.0, and the version of single-spa installed via the CLI is 4.4.2.
We’ll follow these steps to create the container app (also sometimes called the root config):
Shell
mkdir single-spa-demo
cd single-spa-demo
mkdir single-spa-demo-root-config
cd single-spa-demo-root-config
npx create-single-spa
We’ll then follow the CLI prompts:
Great! Now, if you check out the single-spa-demo-root-config
directory, you should see a skeleton root config app. We’ll customize this in a bit, but first let’s also use the CLI tool to create our other three micro-frontend apps.
To generate our first micro-frontend app, the navbar, we’ll follow these steps:
Shell
cd ..
mkdir single-spa-demo-nav
cd single-spa-demo-nav
npx create-single-spa
We’ll then follow the CLI prompts:
Now that we’ve created the navbar app, we can follow these same steps to create our two page apps. But, we’ll replace each place we see “single-spa-demo-nav” with “single-spa-demo-page-1” the first time through and then with “single-spa-demo-page-2” the second time through.
At this point we’ve generated all four apps that we need: one container app and three micro-frontend apps. Now it’s time to hook our apps together.
#javascript #web development #microservices #heroku #microservice architecture #appdev #frontend #frontend web developer #container development #microfrontends