Dynamically created widgets are not updated in Blink

[chfin]

The bug

Widgets that are dynamically (re)created and included in the ui via observables are not updated when using Blink. The following example is a simplified version of the "dynamic buttons" example in the Interact.jl tutorial.

btnshuffle = button("Shuffle")
buttons = Observable{Any}(dom"div"())
number = Observable(3)
map!(number, btnshuffle) do _
    rand(1:10)
end

function makebuttons(n)
    btns = [button(string("button ", i)) for i in 1:n]
    dom"div"(hbox(btns))
end

map!(makebuttons, buttons, number)

ui = dom"div"(btnshuffle, number, buttons)

When number is reassigned, the list of buttons is updated and shown in Jupyter but on in Blink.

Context

Provider: Blink
Errors: none (neither on REPL nor on Blink console)
]status -m WebIO Blink:

    Status `~/Uni/phd/code/schema_annotations/Manifest.toml`
  [bf4720bc]   AssetRegistry v0.1.0
  [9e28174c] + BinDeps v0.8.10
  [ad839575] + Blink v0.12.0
  [34da2185] ↑ Compat v2.1.0 ⇒ v2.2.0
  [de31a74c]   FunctionalCollections v0.5.0
  [97c1335a]   JSExpr v0.5.1
  [682c06a0]   JSON v0.21.0
  [50d2b5c4] ↓ Lazy v0.14.0 ⇒ v0.13.2
  [1914dd2f]   MacroTools v0.5.1
  [ffc61752] + Mustache v0.5.13
  [a975b10e]   Mux v0.7.0
  [510215fc]   Observables v0.2.3
  [189a3867]   Reexport v0.2.0
  [ae029012]   Requires v0.5.2
  [0f1e0344]   WebIO v0.8.11
  [104b5d7c]   WebSockets v1.5.2
  [cc8bc4a8]   Widgets v0.6.2
  [2a0f44e3]   Base64 
  [8ba89e20]   Distributed 
  [56ddb016]   Logging 
  [44cfe95a]   Pkg 
  [9a3f8284]   Random 
  [6462fe0b]   Sockets 
  [cf7118a7]   UUIDs 

versioninfo():

Julia Version 1.2.0
Commit c6da87ff4b (2019-08-20 00:03 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: Intel(R) Core(TM) i7-7600U CPU @ 2.80GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-6.0.1 (ORCJIT, skylake)

[JobJob]

Hi, thanks for the detailed report, sorry no one's had a chance to look at this until now.

Can you try from the Pkg REPL: add Blink#jb/fix-isopen and let me know if it works for you?

It fixes your example for me.

[chfin]

Yes, that works. Thanks a lot!

[JobJob]

I don't think this has been fixed on mainline Blink yet, so reopening.