# How to start with clj + shadow-cljs + rum
**URL:** https://clojureverse.org/t/how-to-start-with-clj-shadow-cljs-rum/7403
**Category:** Beginners
**Created:** [March 28, 2021, 7:10pm UTC](https://clojureverse.org/t/how-to-start-with-clj-shadow-cljs-rum/7403 "2021-03-28T19:10:22Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@stephen](https://clojureverse.org/u/stephen)
#### Post date: [March 28, 2021, 7:10pm UTC](https://clojureverse.org/t/how-to-start-with-clj-shadow-cljs-rum/7403/1 "2021-03-28T19:10:23Z")
I would like to get started experimenting with a fullstack clojure/clojureScript application.
To learn to understand the basic structure I’d like to use the most basic tooling, no lein, no figwheel, no boot, no luminus. Only Clojure (+ring +reitit +rum) and ClojureScript (+rum +shadow-cljs)
What I try to get going is the following:
- a Clojure Server that serves a serverside (pre-)rendered rum component that gets fully hydrated from cljs
- all of that with that “great dynamic clojurey workflow” (instant live reloading)
- a live clj REPL
- a live cljs REPL
Can someone please point me in the right directions?
The most promising template I found was [GitHub - mdiin/happlate: A template for awesome web apps, based on Hoplon, Postgresql and RPC communication.](https://github.com/mdiin/happlate) but I always get errors…
I would be really happy if someone could help me get started
---
### Author:  [@Serioga](https://clojureverse.org/u/Serioga)
#### Post date: [March 28, 2021, 8:28pm UTC](https://clojureverse.org/t/how-to-start-with-clj-shadow-cljs-rum/7403/2 "2021-03-28T20:28:46Z")
You can look at my (opinionated) template [GitHub - serioga/webapp-clojure-2020: Multi-page web application prototype with Clojure(Script)](https://github.com/serioga/webapp-clojure-2020)
---
### Author:  [@stephen](https://clojureverse.org/u/stephen)
#### Post date: [March 29, 2021, 8:20pm UTC](https://clojureverse.org/t/how-to-start-with-clj-shadow-cljs-rum/7403/3 "2021-03-29T20:20:38Z")
It took me quite a while, but I have a good place to start now:
> **[Steffen / Fullstack Clojure with Rum Template](https://gitlab.com/StephenBDT/fullstack-clojure-with-rum-template)**
>
> GitLab.com
Please give some feedback
---
### Author:  [@stephen](https://clojureverse.org/u/stephen)
#### Post date: [March 30, 2021, 9:18pm UTC](https://clojureverse.org/t/how-to-start-with-clj-shadow-cljs-rum/7403/4 "2021-03-30T21:18:49Z")
It is still not working. The first render with Shadow-Cljs works but when the file gets saved, shadow-cljs reloads and reexecutes the file and then the result is:
```auto
45 | (rum/defc item [data]
46 | [:div.item
47 | [:div.picture (picture "https://t1p.de/adga")]
48 | [:div.title (:title data)]])
------------------------------^-------------------------------------------------
Use of undeclared Var projectname.core/data
--------------------------------------------------------------------------------
```
All I do, is the following in `src/cljs/projectname.cljs`:
```auto
(ns projectname.core
(:require [rum.core :as rum]))
(def item_data
{:title "testitem"
:main-picture-url "https://t1p.de/adga"})
(rum/defc picture [url]
[:img {:src url :loading "lazy" :alt "Productpicture"}])
(rum/defc item [data]
[:div.item
[:div.picture (picture "https://t1p.de/adga")] ;;(:main-picture-url data))]
[:div.title (:title data)]])
(defonce item_comp (item item_data))
(rum/mount item_comp (js/document.getElementById "item-container"))
```
the `defonce` is already a desperate attempt to fix this… ☹
---
### Author:  [@stephen](https://clojureverse.org/u/stephen)
#### Post date: [March 31, 2021, 1:21pm UTC](https://clojureverse.org/t/how-to-start-with-clj-shadow-cljs-rum/7403/5 "2021-03-31T13:21:44Z")
Okay, this seems to be a bug with rum. A bugreport was filed:
>
>
> 5 | (rum/defc hello-world \[g\]
> 6 | \[:div
> 7 | \[:h2 g\]
> \---------------^----------------------------------------------------------------
> Use of undeclared Var shadow-rum.core/g
> This happens when shadow-cljs reloads my...
---
### Author:  [@thheller](https://clojureverse.org/u/thheller)
#### Post date: [March 31, 2021, 1:43pm UTC](https://clojureverse.org/t/how-to-start-with-clj-shadow-cljs-rum/7403/6 "2021-03-31T13:43:21Z")
FWIW I just tested this and it is working completely fine without any warnings?
```auto
(ns projectname.core
(:require [rum.core :as rum]))
(defonce app-state (atom {:text "Hello world!"}))
(rum/defc hello-world [data]
[:div
[:h1 (:text @app-state)]
[:h3 "Edit this and watch it change!" (:foo data)]])
(defn start []
;; start is called by init and after code reloading finishes
;; this is controlled by the :after-load in the config
(rum/mount (hello-world {:foo "bar"})
(. js/document (getElementById "app"))))
(defn ^:export init []
;; init is called ONCE when the page loads
;; this is called in the index.html and must be exported
;; so it is available even in :advanced release builds
(start))
(defn stop []
;; stop is called before any code is reloaded
;; this is controlled by :before-load in the config
(js/console.log "stop"))
```
with
```auto
:dependencies [[binaryage/devtools "0.9.7"]
[rum "0.12.4"]
;; fork to support react 16
;; [ua.modnakasta/rum "0.11.0-2"]
[org.roman01la/citrus "3.0.0" :exclusions [rum]]
]
```
running `shadow-cljs watch app` and `http://localhost:8700/`.
Anything I’m missing?
---
### Author:  [@stephen](https://clojureverse.org/u/stephen)
#### Post date: [March 31, 2021, 6:49pm UTC](https://clojureverse.org/t/how-to-start-with-clj-shadow-cljs-rum/7403/7 "2021-03-31T18:49:03Z")
I am beginning to question my sanity xD.
I copy pasted the code you just quoted here and it WORKED!
I did copy it from the state where it didnt!!
maybe I am just not seeing right, and there is an obvious typo somewhere, if that is the case, I feel really sorry 🙂
---
### Author:  [@system](https://clojureverse.org/u/system)
#### Post date: [September 30, 2021, 6:49am UTC](https://clojureverse.org/t/how-to-start-with-clj-shadow-cljs-rum/7403/8 "2021-09-30T06:49:41Z")
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