Fix installation of JupyterLab extension. (#365)

* Fix installation of JupyterLab extension.

* Prompt to auto-install NodeJS.

* Improve documentation for troubleshooting.

* Remove Compat dependency.

* Update TravisCI to not use nightly.

.travis.yml

@@ -7,23 +7,23 @@ jobs:
       julia: 0.7
       env: TESTCMD="xvfb-run julia"
     - os: linux
-      julia: 1.1
+      julia: 1.0
       env: TESTCMD="xvfb-run julia"
     - os: linux
-      julia: nightly
+      julia: 1.3
       env: TESTCMD="xvfb-run julia"
     - os: osx
       julia: 0.7
       env: TESTCMD="julia"
     - os: osx
-      julia: 1.1
+      julia: 1.0
       env: TESTCMD="julia"
     - os: osx
-      julia: nightly
+      julia: 1.3
       env: TESTCMD="julia"
 
     - stage: "Documentation"
-      julia: 1.1
+      julia: 1.3
       os: linux
       script:
         - julia --project=docs/ -e '

Project.toml

@@ -12,7 +12,6 @@ UUIDs = "cf7118a7-6976-5b1a-9a39-7adc72f591a4"
 Distributed = "8ba89e20-285c-5b6f-9357-94700520ee1b"
 Widgets = "cc8bc4a8-27d6-5769-a93b-9d913e69aa62"
 JSON = "682c06a0-de6a-54ab-a142-c8b1cf79cde6"
-Compat = "34da2185-b29b-5c13-b0c7-acf172513d20"
 Base64 = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"
 WebSockets = "104b5d7c-a370-577a-8038-80a2059c5097"
 FunctionalCollections = "de31a74c-ac4f-5751-b3fd-e18cd04993ca"

deps/jupyter.jl

@@ -83,46 +83,96 @@ function install_jupyter_serverextension()
     return nothing
 end
 
+function find_condajl_jupyter_cmd(;
+    check_nodejs::Bool=false,
+)::Cmd
+    conda_root = joinpath(first(Base.DEPOT_PATH), "conda", "3")
+    conda_bin_dir = joinpath(
+        conda_root,
+        @static(Sys.iswindows() ? "Scripts" : "bin"),
+    )
+
+    jupyter = joinpath(conda_bin_dir, exe("jupyter"))
+    if !isfile(jupyter)
+        error(
+            "Could not find the Conda.jl `jupyter` executable " *
+            "(is it installed?)."
+        )
+    end
+
+    # We need to add Conda's bin directory to the PATH so that jupyterlab can
+    # detect nodejs.
+    conda_env = copy(ENV)
+    conda_env["PATH"] = string(conda_bin_dir, ":", conda_env["PATH"])
+    cmd = Cmd(`$jupyter`, env=conda_env)
+
+    if check_nodejs
+        node_exe = joinpath(conda_bin_dir, exe("node"))
+        if !Sys.isfile(node_exe)
+            install_node = Base.prompt(
+                "NodeJS is not installed in your Conda environment " *
+                "but is neccessary to install the JupyterLab extension. " *
+                "Install it? [Y/n]"
+            )
+            if isyes(install_node)
+                @eval Main using IJulia
+                @eval Main.IJulia Conda.add("nodejs")
+            end
+        end
+    end
+
+    return cmd
+end
+
+function find_path_jupyter_cmd()::Cmd
+    jupyter = Sys.which("jupyter")
+    if jupyter === nothing
+        error("Could not find `jupyter` executable in PATH.")
+    end
+    return `$jupyter`
+end
+
 """
-    find_jupyter_cmd()
+    find_jupyter_cmd([; conda=false])
 
 Find the most likely candidate for the `jupyter` executable.
 This will locate `jupyter` by searching the `PATH` environment variable and,
 if not found, tries to return Conda.jl's jupyter.
 If both of these approaches fail, an error is thrown.
 """
-function find_jupyter_cmd(; force_conda_jupyter::Bool=false)::Cmd
+function find_jupyter_cmd(;
+    # DEPRECATED: use `condajl` keyword argument
+    force_conda_jupyter::Union{Nothing, Bool}=nothing,
+    condajl::Union{Nothing, Bool}=force_conda_jupyter,
+    check_nodejs::Bool=false,
+)::Cmd
     # Try to find the "system" Jupyter (unless we explicitly want to force
     # using IJulia's Jupyter installation).
-    if !force_conda_jupyter
-        jupyter = Sys.which("jupyter")
-        if jupyter !== nothing
-            return `$jupyter`
+    if condajl === nothing || condajl === false
+        try
+            return find_path_jupyter_cmd()
+        catch
+            # If conda is false, we explicitly don't want to look for jupyter
+            # in Conda.jl's installation, so we fail now.
+            # Otherwise, conda is nothing and we can continue searching.
+            if condajl === false
+                rethrow()
+            end
         end
     end
 
-    # Try to find IJulia/Conda.jl's Jupyter.
-    # This is a heuristic - it might be different. I'm not sure that there's
-    # an easy way to load Conda.jl (I tried adding it to extras but no dice).
-    conda_root = joinpath(first(Base.DEPOT_PATH), "conda", "3")
-    @static if Sys.iswindows()
-        jupyter = joinpath(conda_root, "Scripts", "jupyter.exe")
-    else
-        jupyter = joinpath(conda_root, "bin", "jupyter")
-    end
-
-    if isfile(jupyter)
-        return `$jupyter`
+    try
+        return find_condajl_jupyter_cmd(check_nodejs=check_nodejs)
+    catch
+        if condajl === nothing
+            error("Could not find `jupyter` executable in PATH or Conda.jl.")
+        end
+        rethrow()
     end
-    @error(
-        "Unable to find a jupyter executable after searching PATH and Conda.jl.",
-        PATH=ENV["PATH"], conda_root,
-    )
-    error("Could not find the Jupyter executable.")
 end
 
 """
-    install_jupyter_labextension([jupyter]; force_conda_jupyter=false)
+    install_jupyter_labextension([jupyter]; condajl=false)
 
 Install the Jupyter Lab extension for WebIO using the specified `jupyter`
 executable.
@@ -137,12 +187,14 @@ provides some more information (and caveats) about the relationship between
 Jupyter Lab and WebIO.
 """
 function install_jupyter_labextension(
-        jupyter::Union{Nothing, Cmd}=nothing;
-        force_conda_jupyter::Bool=false,
+        jupyter::Union{Cmd, Nothing}=nothing;
+        # Deprecated: use `condajl` keyword argument.
+        force_conda_jupyter::Union{Bool, Nothing}=nothing,
+        condajl::Union{Bool, Nothing}=force_conda_jupyter,
         dev::Bool=isdev()
 )
     if jupyter === nothing
-        jupyter = find_jupyter_cmd(; force_conda_jupyter=force_conda_jupyter)
+        jupyter = find_jupyter_cmd(; condajl=condajl, check_nodejs=true)
         @info(
             "Using default Jupyter executable at $jupyter; to use a different "
             * "executable, see the documentation by running "
@@ -229,3 +281,11 @@ function jupyter_config_dir()
 end
 jupyter_nbextensions_dir() = joinpath(jupyter_data_dir(), "nbextensions")
 jupyter_nbconfig_dir() = joinpath(jupyter_config_dir(), "nbconfig")
+
+isyes(s) = isempty(s) || lowercase(strip(s)) in ("y", "yes")
+
+@static if Sys.iswindows()
+    exe(x::String) = endswith(x, "exe") ? x : string(x, ".exe")
+else
+    exe(x::String) = x
+end

docs/src/providers/ijulia.md

@@ -1,5 +1,9 @@
 # IJulia
 
+## WebIO Not Detected
+For troubleshooting information, visit the [WebIO Not Detected](@ref) section
+of the documentation.
+
 ## JupyterLab Considerations
 JupyterLab presents a few issues that are different that than those associated
 with the classic notebook.

docs/src/troubleshooting/not-detected.md

@@ -4,14 +4,27 @@ You may see this message in your frontend if WebIO is unable to find the active
 WebIO instance in the browser.
 
 ## Troubleshooting Jupyter
-This occurs most often when running in Jupyter when the frontend extensions
-aren't installed correctly. Please check the [IJulia](@ref) documentation for
-information about installing the frontend extensions. If you still have issues,
-(after running the appropriate `WebIO.install_jupyter_XXXextension()` function
-and refreshing the browser), keep reading.
+WebIO requires the installation of a Jupyter extension to function properly.
 
-Before continuing, make sure the correct Jupyter is the first `jupyter` in your
-`PATH`.
+If you're using Jupyter Notebook (classic), run the following.
+```julia
+using WebIO
+WebIO.install_jupyter_nbextension()
+```
+
+If you're using Jupyter Lab, run the following.
+```julia
+using WebIO
+WebIO.install_jupyter_nbextension()
+
+# Or, if you are launching via IJulia.jupyterlab()
+using WebIO
+WebIO.install_jupyter_labextension(condajl=true)
+```
+
+Jupyter Lab poses some additional issues that the classic notebook does not.
+For more information on those difficulties, read the [IJulia](@ref)
+documentation.
 
 ### Jupyter Notebook
 List all extensions by running
@@ -26,8 +39,8 @@ For example,
 jupyter nbextension uninstall --user webio/main
 jupyter nbextension uninstall --user webio-jupyter-notebook
 ```
-(note that this may error if you don't actually have those extensions installed
-and that's okay).
+(note that this may print an error if you don't actually have those extensions
+installed and that's okay).
 
 Re-install the Jupyter notebook extension by running (at the Julia REPL)
 ```julia
@@ -42,9 +55,12 @@ using WebIO
 WebIO.install_jupyter_labextension()
 ```
 
-Note that JupyterLab has more pitfalls relating to which `jupyter` executable
-is in the path. Make sure that the Jupyter you're using (you can determine this
-by running `which jupyter`) is the Jupyter that you expect.
+If you launch Jupyter by running `IJulia.jupyterlab()`, run the following
+instead.
+```julia
+using WebIO
+WebIO.install_jupyter_labextension(condajl=true)
+```
 
 ## Still having problems?
 Open a [GitHub issue](https://github.com/JuliaGizmos/WebIO.jl/issues/new).

src/render.jl

@@ -196,10 +196,13 @@ function Base.show(io::IO, m::MIME"text/html", x::Node)
                 document
                     .querySelector('[data-webio-mountpoint="$(mountpoint_id)"]')
                     .innerHTML = (
-                        '<strong>WebIO not detected. Please read ' +
-                        '<a href="https://juliagizmos.github.io/WebIO.jl/latest/troubleshooting/not-detected/">the troubleshooting guide</a> ' +
-                        'for more information on how to resolve this issue.' +
-                        '</strong>'
+                        '<div style="padding: 1em; background-color: #f8d6da; border: 1px solid #f5c6cb">' +
+                        '<p><strong>WebIO not detected.</strong></p>' +
+                        '<p>Please read ' +
+                        '<a href="https://juliagizmos.github.io/WebIO.jl/latest/troubleshooting/not-detected/" target="_blank">the troubleshooting guide</a> ' +
+                        'for more information on how to resolve this issue.</p>' +
+                        '<p><a href="https://juliagizmos.github.io/WebIO.jl/latest/troubleshooting/not-detected/" target="_blank">https://juliagizmos.github.io/WebIO.jl/latest/troubleshooting/not-detected/</a></p>' +
+                        '</div>'
                     );
             }
             </script>

src/scope.jl

@@ -14,7 +14,7 @@ export Scope,
        import!,
        addconnection!
 
-import Compat.Sockets: send
+import Sockets: send
 import Observables: Observable, AbstractObservable, listeners
 
 # bool marks if it is synced