# Is anyone developing a SPA package like R/Shiny or Python/Dash?
**URL:** https://discourse.julialang.org/t/is-anyone-developing-a-spa-package-like-r-shiny-or-python-dash/5733
**Category:** Web Stack
**Created:** [September 5, 2017, 5:49pm UTC](https://discourse.julialang.org/t/is-anyone-developing-a-spa-package-like-r-shiny-or-python-dash/5733 "2017-09-05T17:49:58Z")
**Posts on this page:** 20
**Page:** 1
I’m working on a simple climate model that I would like to put online with some nice and friendly widgets. It would be a perfect fit for a Single Page Application, especially if Julia had a package that made this as simple as [Shiny](https://shiny.rstudio.com/) for R or [Dash](https://plot.ly/products/dash/) for Python. I’m a complete webapp newbie, so doing it [manually](http://www.stochasticlifestyle.com/building-web-app-julia-differentialequations-jl-online/) like @ChrisRackauckas isn’t on the table, at least not yet.
Is anyone already working on something similar for Julia? (Shoutout to @essenciary, developer of Genie.jl: you mentioned on Gitter last month that you might have a look at Shiny. Is this still on the map? Have you considered Dash as well?)
I think a simple webapp package like this would do wonders for evangelizing Julia. Oh incidentally, Shiny is GPL-3 and Dash is MIT licensed, so there are valuables lying around there just waiting to be stolen, hint hint … 🙂
---
Yes, that’s definitely on the roadmap but I can’t report any significant progress yet. I know Shiny, but Dash looks great and I’ll check it out too, thanks for the tip!
My plan is to use an existing UI toolkit and after some research, I identified 3 main options:
Syncfusion [Modern HTML5 and JavaScript UI Controls Library | Syncfusion](https://www.syncfusion.com/products/javascript)
OpenUi5 [http://openui5.org/](http://openui5.org/)
PredixUI [Predix UI – Learn From Scratch](https://www.predix-ui.com/#/home)
If anybody can recommend other ones, please share.
The first 2 require generating an ungodly amount of JavaScript in order to setup and configure the UI elements - and generating JS from Julia sounds like a bad idea (if you know of any good way to do it, please comment, that would open interesting possibilities).
PredixUI looks like the best choice as the UI elements can be configured with JSON alone, providing a nice way of exchanging information between the Julia and the JS layers.
But all is not well with Predix either:
a. it uses Polymer 1 which is old and has performance problems. I followed up with the developers and they do plan to migrate it to Polymer 2 but there’s no time frame.
b. in terms of JS tooling, it uses Bower to manage dependencies, which is deprecated in favor of Yarn plus Webpack. Genie already uses Yarn and Webpack so I’m very reluctant to add Bower into the mix just to support PredixUI until it gets upgraded.
c. licensing and distribution - I don’t fully understand the PredixUI license (which is a General Electric license). But I expect this can be circumvented by simply not distributing the UI library files with Genie and providing a script to automatically download it and configure it on the dev machine. But still, I need to know for sure before committing to this approach (if anybody has a US legal background, I’d appreciate help in this regard).
So, for now, I’m playing the waiting game and hoping PredixUI will get upgraded - while focusing on the Genie core (full support for Julia v0.6 and v0.7 plus proper documentation and guides). Hopefully, by the time I’m ready with the Genie parts, PredixUI will be in a better state (it is actively developed by GE and that’s a good start).
Feedback appreciated.
---
I’m very glad that this is on the radar for Genie!!
I know very little about web development, but since I want to dip my toes a bit I’ve been reading up lately on UI frameworks, and I haven’t seen any mention at all of any of those three toolkits you are considering. I find that slightly concerning (but again, I’m no expert). It seems that all the buzz these days is about React and its main competitors Angular, Vue.js, Riot and many others. Have you eliminated these from consideration for some reason? If so, why?
Out of these, React seems to be the heavyweight, and this is the UI framework that Dash is built on. But I would probably be tempted to use the up-and-coming Vue.js. It supposedly has an amazing API and documentation, and it requires [less boilerplate](http://www.dotnetcurry.com/vuejs/1372/vuejs-vs-angular-reactjs-compare) and [is faster](http://www.stefankrause.net/wp/?p=431) than the main competitors. Also, while there’s been a [brouhaha](https://wptavern.com/react-users-petition-facebook-to-re-license-react-js-after-apache-software-foundation-bans-bsdpatents-license-in-dependencies) over React’s BSD+Patents license, Vue.js has the Julia-preferred MIT license.
For technical details, the Vue.js team provide a [detailed comparison with other frameworks](https://vuejs.org/v2/guide/comparison.html).
---
I’m very familiar with Vue, Angular, React, etc. But they’re not the same thing. The ones I mentioned are UI components libraries - they are one level of abstraction higher up the web stack (above web frameworks).
Like you say, Dash is _built on React_ - Predix and the others are _like Dash_ (built on top of other libraries or frameworks), and _not like React_ (not frameworks). Predix builds on Polymer (which is Google’s) and the others use jQuery (if I remember correctly).
I considered using Vue but my research showed that there is no mature set of UI components based on Vue. There are some early attempts, but none of them have powerful or diverse enough UI elements, especially not for data vis. One option would’ve been to mash up multiple Vue components from various developers - but that would lead to different coding styles and integration strategies. So poor quality.
PredixUI is very polished and is actively developed by a billion $ company (it’s a GE product used by them for their dashboards). And it’s running on Polymer, another actively developed project backed by a billion $ company (Google). It has a huge library of elements with everything that’s needed, from buttons to powerful data visualization (check out the time series UI component for a quick example, using D3: [Predix UI – Learn From Scratch](https://www.predix-ui.com/#/elements/vis/px-vis-timeseries)).
---
Could all the web devs that use Julia get in a room somehow and hash through this?
This seems like an extremely opinionated project that might otherwise spawn as many packages as there are javascript frameworks
I’m not saying @essenciary, @shashi, @jobjob, and @dfdx actually get a room, but maybe a google-hangout/gitter/slack would suffice?
* * *
> **[Standards](https://xkcd.com/927/)**
>
> Fortunately, the charging one has been solved now that we've all standardized on mini-USB. Or is it micro-USB? Shit.
---
> [@essenciary](#):
>
> generating JS from Julia sounds like a bad idea (if you know of any good way to do it, please comment, that would open interesting possibilities).
I can’t say I do (there was a small demo, in some Github issue…); I see WebAssembly generation, rather than JS or asm.js, as the future (likely possible already), for Julia code, but interacting with JS seems still needed? asm.js interacts perfectly as just a JS subset, but I believe WebAssemly ↔ is more complicated. Just look it up (and then GC missing, Julia would probably prefer that - to provide its own).
> [@NickNack](#):
>
> there’s been a brouhaha over React’s BSD+Patents license, Vue.js has the Julia-preferred MIT license.
BSD works well with MIT?! “BSD+Patents license” + MIT also I believe, while yes some disagree (Apache foundation). That stance may be overblown and not affect Julia even with:
This issue was closed (and the situation unchanged; unlike for e.g. Facebook’s Zstandard that just took out the PATENTS file - they actually had no patent on the compression standard it seems):
>
>
> Hi there,
>
> The Apache Software Foundation Legal Affairs Committee \[has announc…ed\]\[1\] that the so-called 'Facebook BSD+Patents License' is no longer allowed to be used as a direct dependency in Apache projects.
>
> This has lead to a lot of upset and frustration in the Apache community, especially from projects requiring similarly-licensed code as direct dependencies - the chief of these being RocksDB.
>
> However, we (the Apache Software Foundation) have just received word that \[RocksDB will be re-licensing their code under the dual Apache License v2.0 and GPL 2 licenses\]\[2\].
>
> As a user of React.JS in an ASF top-level project (Apache CouchDB), please consider re-licensing React.JS under similar terms. Otherwise, many ASF projects such as our own will have to stop relying on and building with React.
>
> A previous bug (#9760) suggested I mention @lacker in this issue when asking licensing questions, so I'm doing so.
>
> Thank you kindly for your consideration.
>
> \[1\]: https://issues.apache.org/jira/browse/LEGAL-303?focusedCommentId=16088663&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-16088663
> \[2\]: https://issues.apache.org/jira/browse/LEGAL-303?focusedCommentId=16088730&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-16088730
---
I’m quite suspicious of generating front-end components at the back-end. I’ve seen several frameworks for it throughout the years, but every time it projects ended up rewriting everything into something less coupled. Also, snippets like this from Dash:
```python
app.layout = html.Div([
html.H1('Stock Tickers'),
dcc.Dropdown(
id='my-dropdown',
options=[
{'label': 'Coke', 'value': 'COKE'},
{'label': 'Tesla', 'value': 'TSLA'},
{'label': 'Apple', 'value': 'AAPL'}
],
value='COKE'
),
dcc.Graph(id='my-graph')
])
```
makes me think that I still will have to learn front-end (or at least HTML) **and** also learn how to generate it from back-end.
Maybe a better way would be to create a good tutorial / example of such a dashboard built on top of existing components. A little Genie server exposing data via HTTP and an example page with a few Vue.js components should be an easy to grasp even for a complete newbie in web programming, still not locking a user to a specific framework.
> Could all the web devs that use Julia get in a room somehow and hash through this?
Not sure I will be very helpful, but feel free to create a Gitter/Slack channel and ping me to join.
---
> [@dfdx](#):
>
> I’m quite suspicious of generating front-end components at the back-end.
I doubt Dash has the best solution for specifying layout, but I’m quite attracted to the idea of being able to make simple web apps directly from Julia without writing any HTML or CSS (or at least without most of the boilerplate).
> [@](#):
>
> … makes me think that I still will have to learn front-end (or at least HTML) **and** also learn how to generate it from back-end.
I’m sure there were skeptics who said something similar when the first compilers were introduced, but it is sometimes useful to be able to abstract away the underlying technology.
---
Does all the code have to be in Julia?
Maybe you could have handlebars-like files that get compiled through Julia somehow, i.e.
- `*.html.jle`
- `*.css.jle`
- `*.js.jle`
* * *
Another idea would be to use [glimmer](https://glimmerjs.com/) and rely on the [ecosystem](https://emberobserver.com/categories/component-suites) for the level of abstraction you want?
Then you could somehow allow people to edit components/webpages/html+js+css on either the WebApp side or the Julia side?
**edit:** then you could load in different component styles (bootstrap, material design, etc) like how Plots.jl loads in different plotting libraries
---
> [@NickNack](#):
>
> I’m sure there were skeptics who said something similar when the first compilers were introduced, but it is sometimes useful to be able to abstract away the underlying technology.
I gave this example specifically to show that you don’t really get an abstraction layer. The `html.Div` is translated into HTMLs `