Add SimpleVLSpec to make it usable w/o VegaLite for simple plots

Project.toml

@@ -4,7 +4,6 @@ authors = ["Takafumi Arakaki <aka.tkf@gmail.com>"]
 version = "0.1.0-DEV"
 
 [deps]
-Base64 = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"
 Electron = "a1bb12fb-d4d1-54b4-b10a-ee7951ef7ad3"
 ElectronDisplay = "d872a56f-244b-5cc9-b574-2017b5b909a8"
 JSON = "682c06a0-de6a-54ab-a142-c8b1cf79cde6"
@@ -14,7 +13,6 @@ julia = "1"
 
 [extras]
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
-VegaLite = "112f6efa-9a02-5b7d-90c0-432ed331239a"
 
 [targets]
-test = ["Test", "VegaLite"]
+test = ["Test"]

src/VegaStreams.jl

@@ -2,7 +2,6 @@ module VegaStreams
 
 export vegastream
 
-using Base64
 using Electron
 using ElectronDisplay
 using ElectronDisplay: asset, displayhtml, newdisplay
@@ -20,7 +19,8 @@ function vegalite_html(vlspec)
         error(vlspec, " does not support vegalite v2 or v3.")
     end
 
-    payload = stringmime(
+    payload = sprint(
+        show,
         MIME("application/vnd.vegalite.v$major_version_vegalite+json"),
         vlspec,
     )
@@ -79,9 +79,10 @@ end
 
 struct VegaStreamWindow
     window::Electron.Window
+    processrow
 end
 
-function vegastream(vlspec; kwargs...)
+function vegastream(vlspec; processrow=identity, kwargs...)
     html_page = vegalite_html(vlspec)
 
     # Using ElectronDisplay internals to support `single_window = false`.
@@ -98,15 +99,38 @@ function vegastream(vlspec; kwargs...)
     =#
 
     # TODO: wait for VIEW to be set?
-    return VegaStreamWindow(window)
+    return VegaStreamWindow(window, processrow)
 end
 
 Base.push!(stream::VegaStreamWindow, row) = append!(stream, [row])
 
 function Base.append!(stream::VegaStreamWindow, rows)
-    json = JSON.json(collect(rows))
+    json = JSON.json(collect(map(stream.processrow, rows)))
     run(stream.window, "appendRows($json)")
     return stream
 end
 
+vegastream(vlspec::Dict; kwargs...) = vegastream(SimpleVLSpec(vlspec); kwargs...)
+
+vegastream(mark::Symbol = :line; kwargs...) =
+    vegastream(SimpleVLSpec(mark); processrow = NamedTuple{(:x, :y)}, kwargs...)
+
+struct SimpleVLSpec
+    params::Dict{String, Any}
+end
+
+SimpleVLSpec(mark::Symbol) =
+    SimpleVLSpec(Dict(
+        "mark" => mark,
+        "encoding" => Dict(
+            "x" => Dict("field" => "x"),
+            "y" => Dict("field" => "y"),
+        )
+    ))
+
+function Base.show(io::IO, ::MIME"application/vnd.vegalite.v3+json", vlspec::SimpleVLSpec)
+    JSON.print(io, vlspec.params)
+    return
+end
+
 end # module

test/runtests.jl

@@ -1,10 +1,14 @@
-using VegaLite
 using VegaStreams
 using Test
 
 @testset "VegaStreams.jl" begin
-    vls = vegastream(@vlplot(:line, x=:x, y=:y))
+    vls = vegastream()
+    for row in enumerate(randn(100))
+        sleep(0.01)
+        push!(vls, row)
+    end
 
+    vls = vegastream(:point)
     for (x, y) in enumerate(randn(100))
         sleep(0.01)
         push!(vls, (x=x, y=y))