new init logic; fix pyplot subplot bug

src/Plots.jl

@@ -186,10 +186,10 @@ yaxis!(plt::Plot, args...; kw...)                                     = plot!(pl
 # ---------------------------------------------------------
 
 
-try
-  import DataFrames
-  dataframes()
-end
+# try
+#   import DataFrames
+#   dataframes()
+# end
 
 # const CURRENT_BACKEND = pickDefaultBackend()
 
@@ -202,18 +202,21 @@ end
 #   end
 # end
 
+const CURRENT_BACKEND = CurrentBackend(:none)
 
-function __init__()
-  global const CURRENT_BACKEND = pickDefaultBackend()
-  # global CURRENT_BACKEND
-  # println("[Plots.jl] Default backend: ", CURRENT_BACKEND.sym)
+# function __init__()
+#   # global const CURRENT_BACKEND = pickDefaultBackend()
+#   # global const CURRENT_BACKEND = CurrentBackend(:none)
 
-  # # auto init dataframes if the import statement doesn't error out
-  # try
-  #   @eval import DataFrames
-  #   dataframes()
-  # end
-end
+#   # global CURRENT_BACKEND
+#   # println("[Plots.jl] Default backend: ", CURRENT_BACKEND.sym)
+
+#   # # auto init dataframes if the import statement doesn't error out
+#   # try
+#   #   @eval import DataFrames
+#   #   dataframes()
+#   # end
+# end
 
 # ---------------------------------------------------------
 

src/backends/pyplot.jl

@@ -568,7 +568,7 @@ function subplot(plts::AVec{Plot{PyPlotPackage}}, layout::SubplotLayout, d::Dict
   n = sum([plt.n for plt in plts])
 
   pkg = PyPlotPackage()
-  newplts = Plot{PyPlotPackage}[plot(pkg; subplot=true, plt.plotargs...) for plt in plts]
+  newplts = Plot{PyPlotPackage}[_create_plot(pkg; subplot=true, plt.plotargs...) for plt in plts]
 
   subplt = Subplot(nothing, newplts, PyPlotPackage(), p, n, layout, d, true, false, false, (r,c) -> (nothing,nothing))
 

src/plotter.jl

@@ -8,6 +8,7 @@ immutable UnicodePlotsPackage <: PlottingPackage end
 immutable WinstonPackage      <: PlottingPackage end
 immutable BokehPackage        <: PlottingPackage end
 immutable PlotlyPackage       <: PlottingPackage end
+immutable NoPackage           <: PlottingPackage end
 
 typealias GadflyOrImmerse @compat(Union{GadflyPackage, ImmersePackage})
 
@@ -37,6 +38,7 @@ backend_name(::UnicodePlotsPackage) = :unicodeplots
 backend_name(::QwtPackage)          = :qwt
 backend_name(::BokehPackage)        = :bokeh
 backend_name(::PlotlyPackage)       = :plotly
+backend_name(::NoPackage)           = :none
 
 include("backends/supported.jl")
 
@@ -81,6 +83,7 @@ function backendInstance(sym::Symbol)
   sym == :winston && return WinstonPackage()
   sym == :bokeh && return BokehPackage()
   sym == :plotly && return PlotlyPackage()
+  sym == :none && return NoPackage()
   error("Unsupported backend $sym")
 end 
 
@@ -93,39 +96,48 @@ CurrentBackend(sym::Symbol) = CurrentBackend(sym, backendInstance(sym))
 
 # ---------------------------------------------------------
 
+# function pickDefaultBackend()
+#   try
+#     if Pkg.installed("PyPlot") != nothing
+#       return CurrentBackend(:pyplot)
+#     end
+#   end
+#   try
+#     if Pkg.installed("Immerse") != nothing
+#       return CurrentBackend(:immerse)
+#     end
+#   end
+#   try
+#     if Pkg.installed("Qwt") != nothing
+#       return CurrentBackend(:qwt)
+#     end
+#   end
+#   try
+#     if Pkg.installed("Gadfly") != nothing
+#       return CurrentBackend(:gadfly)
+#     end
+#   end
+#   try
+#     if Pkg.installed("UnicodePlots") != nothing
+#       return CurrentBackend(:unicodeplots)
+#     end
+#   end
+#   try
+#     if Pkg.installed("Bokeh") != nothing
+#       return CurrentBackend(:bokeh)
+#     end
+#   end
+#   # warn("You don't have any of the supported backends installed!  Chose from ", backends())
+#   return CurrentBackend(:plotly)
+# end
+
 function pickDefaultBackend()
-  try
-    if Pkg.installed("PyPlot") != nothing
-      return CurrentBackend(:pyplot)
+  for pkgstr in ("PyPlot", "Immerse", "Qwt", "Gadfly", "UnicodePlots", "Bokeh")
+    if Pkg.installed(pkgstr) != nothing
+      return backend(symbol(lowercase(pkgstr)))
     end
   end
-  try
-    if Pkg.installed("Immerse") != nothing
-      return CurrentBackend(:immerse)
-    end
-  end
-  try
-    if Pkg.installed("Qwt") != nothing
-      return CurrentBackend(:qwt)
-    end
-  end
-  try
-    if Pkg.installed("Gadfly") != nothing
-      return CurrentBackend(:gadfly)
-    end
-  end
-  try
-    if Pkg.installed("UnicodePlots") != nothing
-      return CurrentBackend(:unicodeplots)
-    end
-  end
-  try
-    if Pkg.installed("Bokeh") != nothing
-      return CurrentBackend(:bokeh)
-    end
-  end
-  # warn("You don't have any of the supported backends installed!  Chose from ", backends())
-  return CurrentBackend(:plotly)
+  backend(:plotly)
 end
 
 
@@ -136,6 +148,11 @@ Returns the current plotting package name.  Initializes package on first call.
 """
 function backend()
 
+  global CURRENT_BACKEND
+  if CURRENT_BACKEND.sym == :none
+    pickDefaultBackend()
+  end
+
   currentBackendSymbol = CURRENT_BACKEND.sym
   if !(currentBackendSymbol in INITIALIZED_BACKENDS)