Using a local module file

[MinusOneTwelfth-1]

I have made a simple module file, myModule.jl in the same folder as the Pluto notebook. This module exports a function called myFunction.

In the first cell I have:

begin
	include("myModule.jl")
	using .myModule  
	
end

And in the next cell:

myFunction(3)

After I Shift+Enter that, I get this error:

UndefVarError: myFunction not defined

    top-level scope@Local: 1

... But now if I go back to the top cell and just do Shift+Enter, the second cell shows the correct result.

To sum up,..

After entering myFunction into any cell (or after doing Shift+Enter in an existing cell ) I need to go back to the first cell and do a Shift+Enter again to refresh the module's exports.

I'm working around this by putting myFunction = myModule.myFunction in the first cell, but it would be a pain if I have lots more functions.

Is this a bug or is there something I can do to to make it work?

[icweaver]

Hey @MinusOneTwelfth-1! As far as I can tell, include[t]ing things in Pluto can get a bit dicey sometimes. When I get to the stage of working with modules, I usually just turn what I am working on into a package, which makes a lot of really nice things automatically available, such as the Revise.jl workflow. Using your example above, I would do something like the following:

1. Create a skeleton package

PkgTemplates.jl is awesome for this, and super customizable:

pkg> add PkgTemplates
julia> using PkgTemplates
julia> Template(dir=".")("MyPkg") # This assumes you have your global git configured already

2. Add Revise.jl globally

(or just to your new package, up to you)

pkg> add Revise 

3. Fire up a Pluto.jl notebook

It doesn't really matter where you create the notebook as long as you point it to your package, but I just like keeping everything self-contained in the top-level of my package, so it might look something like this:

MyPkg
├── LICENSE
├── Manifest.toml
├── notebook_MyPkg.jl
├── Project.toml
├── README.md
├── src
│   └── MyPkg.jl
└── test
    └── runtests.jl

Now over in my Pluto.jl notebook (notebook_MyPkg.jl), if I have a cell like this:

begin
    import Pkg
    Pkg.activate(Base.current_project())
    using Revise, MyPkg
end

any changes that I make to the package should be automatically reflected after re-running that cell. For example, if I edit MyPkg/src/MyPkg.jl from:

module MyPkg

export my_function

my_function(x) = x^2

end

to:

module MyPkg

export my_function

my_function(x) = x^3

end

and re-run a Pluto.jl cell with the following:

my_function(3)

the output should update accordingly

[MinusOneTwelfth-1]

Thanks, icweaver ... I had been hesitating to dive into a package based workflow because it seemed a bit daunting as a newcomer to Julia & Pluto. But with your explanations I'm finding it easy to packagize my Pluto work and to use modules etc optimally.

Thanks again.

[floswald]

hey there, this does not seem to work for me anymore. I get this

begin
    import Pkg
    Pkg.activate(Base.current_project())
    using Revise, Plutotest2
end

MethodError: no method matching activate(::Nothing)

Closest candidates are:

activate(; temp, shared, io) at /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/API.jl:1430

activate(!Matched::AbstractString; shared, temp, io) at /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/API.jl:1456

activate(!Matched::Function, !Matched::AbstractString) at /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/API.jl:1497

    top-level scope@Local: 3

it seems the current_project() does return nothing instead of the required path.

[icweaver]

Howdy! Could you verify where your notebook is being saved? I think current_project expects a Project.toml to be somewhere in the parent or current directory of your notebook. If it's a new notebook, then it might have been created in a temporary location, which would explain your error

[floswald]

no idea what happened but it works now. 🤷 did i run this from the vscode terminal before? no idea. anyway, fixed. :-)