hey

i feel like I’m getting better at hoplon in the front end after practicing a bit

anyone have suggestions for a persistent backend for app state?

that works well for hoplon with or without castra?

i see datascript mentioned a lot

is that something worth following up?

it's definitely interesting

it's handy if you want to allow arbitrary queries over the state of your app

or if the logic is expressible as datalog queries

ok

i guess what i’m trying to do, is have state that I can save and load somewhere

and be able to do undo/redo too

you can make do with having the state as a map or the datascript database

doesn't make a difference

my state will probably be either pretty nested

datascript only adds the indices over your data

or split across a lot of cells

whatever is best supported by available tools

if you have something with a lot of nesting and highly dynamic data - I'd look at datascript

well, what i will have is a bunch of page elements that are essentially little forms/inputs

that are repetetive

and need to have all their values aggregated into something that can be computed globally

so yeah, either nested

or lots of little things with predictable structure that i can vacuum up

if there’s a tool (like datascript) that naturally lends itself to the nested approach

then i guess that helps me decide how to tackle this

is there a way to grab the whole datascript state and stick it somewhere on the backend?

@thedavidmeister: check out storage-atom, you can save an atom to a file in clj

Wildly inefficient and problematic but sometimes just what you need. Err: enduro is the project

@alandipert: i got storage-atom working for localstorage

it’s cool

https://github.com/alandipert/enduro

i guess i’m worried about what happens with that approach if you have network issues or whatever

Firebase is another cool thing, at least for hobby projects

i keep hearing about that

haven’t used it

It's hosted db you can interact with via their JS api

So you don't need to host your own backend. They also handle auth

how does storage atom deal with networking issues?

i feel comfortable that localstorage won’t “go away” and mess up your state

less so about remote stuff

The issues will be the same regardless of db choice

@alandipert: did you do any hoplon apps with datascript?

oh I see you only swap! or reset! when someone clicks “save” or whatever

@dm3 only experiments

i currently have my localstorage storage-atom just tracking state in real time

i think i’m going to have to do some more reading

enduro looks like it would struggle if i had 2 or more users

if I understand what is being said under “resource management"

or even just 2 or more states for a single user

ultimate goal is that you could log in as a user, see a list of saved states and load it up

My intermediate-term goal is to have a very simple database that runs both in the browser and the server.

But right now I'm enhancing aatree/dewdrop--as a means of learning more about js.

--and I found some very nice code in javelin/core.cljs that does exactly what I need: deftype Ce;;

https://github.com/hoplon/javelin/blob/master/src/javelin/core.cljs#L71-L101

[ANN] Dewdrop (in aatree/aautil 0.0.4) now supports lens-view. Functions which work with lens-view are the standard @, reset! and swap!. The lens demo in hoplon/demos now employs lens-view. See https://github.com/hoplon/demos/blob/master/lens/src/hl/index.cljs.hl#L10-L16 Thanks to @micha for pointing out the inadequacies of the previous release.

So, what is a lens view? It is the combination of a lens and an atom (or cell). Another example of a lens view is a Javelin formula cell.