clojurescript | source content for the Practicalli , Clojurescript book

I'm building a web app using Clojure and ClojureScript and I need it to have authentication based on a white-list of organization. For example, let's say I've added University1.edu to my white-list, and when a student from that university wants to login to my web app, they would be redirected to their own universities login system. After that I would just a confirmation of whether or not they successfully logged in there and maybe create a session, cookies, or or something for them.

Is that possible and if so, how can I implement that?

This might sound a stupid question, but how do I turn a piece of hiccup into html in a ClojureScript reagent application?

I want something like this :

Using clojurescript 1.10.758 and reagent 1.0.0, I am running into an error in which a file index.js tries to reference $jscomp, which is not defined.

I've seen a number of Stackoverflow and Github issues related to $jscomp being undefined in the context of shadow-cljs, but I'm not using that.

The problem occurs when I use a development mode build with figwheel (using Leiningen with cljsbuild and the figwheel plugin), and also occurs if I use cljsbuild for a once-only development build. Strangely, if I use webpack to create a bundle, the problem does not occur.

Before I tried to make webpack work, I did have working code without webpack. Something I changed seems to have affected the non-bundled build. The only change I can thing of was to install react and react-dom using npm, and exclude those packages from reagent in Leiningen's dependencies. But undoing the exclusion didn't make the non-bundled code work again.

Any suggestions for how to cause $jscomp to be defined when it's first needed?

I am trying to create a simple clojurescript which'll display the width of the browser window.

My app.cljs look like the following:

I'm trying to do some (simple) plots in Clojure and it seems like Oz would be a great long term solution. However, I'm running into problems just trying to get the example code to run. PS I'm completely new to ClojureScript / Reagent / Hiccup ...

On the website it shows the following example code:

What would be an elegant way to find the ba4 values for :foo in a data structure like:

[[{:foo "ba1"}{:foo "ba2"}] [{:foo "ba3"}{:foo "ba4"}]]

and add the :bif "baf" key and value so the map(s) containing the key/value I sought so I had:

[[{:foo "ba1"}{:foo "ba2"}] [{:foo "ba3"}{:foo "ba4" :bif "baf"}]]?

This is the main thing I am trying to figure out; I do wonder about how you would do this if there were multiple levels of nested maps, but that will be next for me to understand.

I have, I think, seen various libraries out there for tackling this sort of thing and I'm not at all against using them, though they would have to work in ClojureScript.

I am trying to update a Reagent atom such that classes will change on a UI element.

I am trying to build on the Pedestal tutorial app available here.

I am trying to add cljs functionality and trying to setup a unified clojurescript and clojure environment.

My deps.edn file looks as follows:

What is the best way in Clojure (actually ClojureScript) to accomplish the following:

• A mutable collection of elements xs, each of type T (T is a map, if we want to be specific)
• A "selected element" among them, x, which alternates between various xs or a "none selected" state. The number of selected items is either 1 or zero.
• xs and x will have event listeners listening to them: some listen for any change in xs; some listen to any change in x. (That is, they listen for both an update in the state of the selected item, as well as a switching of which item is selected.) (I'm actually using the Reagent wrapper for React, so this affects when components will update.)
• Methods to edit x (don't need to edit non-selected xs, though need to be able to add new xs)
• Given an element in xs, a method to select it. (Including the case of select "none")

Possibilities I've thought of so far:

1. Make xs an atom which is a vector of Ts, and make sure every T element knows its own index. Replace x with x_idx which stores the index of the selected item (or nil). Selecting an element just means getting its index and changing x_idx to that index, both of which are constant-time ops. Downsides to this are that it makes the structure a little less elegant and simple: I'm always passing around the index of the selected item, and every operation I want to do has to work with the index instead of the item itself, as it would like to. Since my T objects are small, it would be more pleasing to just have a "selected object" variable which is of type T.
2. Make xs an atom vector and x an atom which stores a T. Now x is a T, which is nice, but when I want to update info about x, I have to make two calls to reset! or swap!: one for x and one for the element in xs which x represents. Inelegant for obvious reasons. And I have to do these in quick succession or else there will be an inconsistency in the data: in between the two calls, the event listeners listening to xs will see the selected item in one state, and the ones listening to x will see it in another state.
3. Give T elements a field to tell if they're selected or not, and get rid of x. This would be right if multiple items could be selected at once, but since only one item can be selected, it just makes me do a linear search every time I want the selected item, which sucks.

The point of this question is not to solve some particular issue (any of the possibilities above work fine for the scope of the small project I'm working on), but to learn about Clojure data structures. This seems like a common enough situation that there would be some structure around it. Responses along the lines of "you should be trying to answer a different question entirely..." are welcome.

I'm trying to create a multipage application with clojurescript. For the react stuff I'm using the helix library. For the reloading I'm using shadow-cljs.

When trying to use the react-router-dom like in javascript it doesn't work.

Here's my code: