Merge pull request #177 from nteract/availableKernels

caching available kernels into config

lib/config.coffee

@@ -0,0 +1,59 @@
+module.exports =
+    languageMappings:
+        title: "Language Mappings"
+        description: 'Some packages may change the name of the grammar for
+                      a language (e.g. "Python" -> "Python Django"). That
+                      leaves Hydrogen unable to figure out what kernel to
+                      use for your code.
+
+                      This field should be valid JSON mapping a nonstandard
+                      language name to a standard one, e.g.
+
+                      ```{"Python Django": "python", "Ruby (Rails)": "ruby"}```'
+        type: 'string'
+        default: '{}'
+    grammarToKernel:
+        description: 'JSON mappings between specific kernel and a
+                      language/grammar. This value is updated automatically
+                      by the "switch kernel" command. If you switch from
+                      python2 to python3, python3 will be used the next time
+                      you open a Python file. You probably shouldn\'t
+                      change this by hand.'
+        type: 'string'
+        default: '{}'
+    kernelspec:
+        title: "Kernel Spec"
+        description: 'This field is autogenerated on every launch in up-to-date environments,
+        also you can regenerate this with hydrogen:update-kernels command.
+        
+        
+        ```
+        Kernel specs as reported by:
+          $ jupyter kernelspecs list --json
+            or
+          $ ipython kernelspecs list --json
+        ```
+
+        If this commands fails in your environment you can use this field to specify your kernels, like:
+        ```
+        {
+          "kernelspecs": {
+            "ijavascript": {
+              "spec": {
+                "display_name": "IJavascript",
+                "env": {},
+                "argv": [
+                  "node",
+                  "/home/user/node_modules/ijavascript/lib/kernel.js",
+                  "--protocol=5.0",
+                  "{connection_file}"
+                ],
+                "language": "javascript"
+              },
+              "resources_dir": "/home/user/node_modules/ijavascript/images"
+            }
+          }
+        }
+        ```'
+        type: 'string'
+        default: '{}'

lib/kernel-manager.coffee

@@ -5,14 +5,36 @@ Kernel = require './kernel'
 
 module.exports = KernelManager =
     runningKernels: {}
-
-    getAvailableKernels: _.memoize ->
+    kernelsUpdatedOnce: false
+
+    getAvailableKernels: ->
+        kernels = _.pluck @getConfigJson('kernelspec', {kernelspecs:{}}).kernelspecs, 'spec'
+        @updateKernels() unless @kernelsUpdatedOnce
+        kernels
+
+    updateKernels: ->
+      saveKernelsToConfig = (out) =>
         try
-            out = child_process.spawnSync('jupyter',['kernelspec','list', '--json']).stdout.toString()
-        catch
-            out = child_process.spawnSync('ipython',['kernelspec','list', '--json']).stdout.toString()
-        _.pluck(JSON.parse(out).kernelspecs, 'spec')
-
+          kernelspec = JSON.parse(out)
+        catch e
+          unless @getAvailableKernels().length
+            atom.notifications.addError """
+              Can't parse neither 'ipython kernelspecs nor 'jupyter kernelspecs'
+              """, detail: """Use kernelspec option in Hydrogen options OR update
+              your ipython/jupyter to version that supports kernelspec option:
+              $ jupyter kernelspec list --json || ipython kernelspec list --json
+              """
+        if kernelspec?
+          @setConfigJson 'kernelspec', kernelspec
+          atom.notifications.addInfo 'Hydrogen Kernels updated:',
+            detail: (_.pluck @getAvailableKernels(), 'display_name').join('\n')
+
+      @kernelsUpdatedOnce = true
+      child_process.exec 'jupyter kernelspec list --json --log-level=CRITICAL', (e, stdout, stderr) ->
+          return saveKernelsToConfig stdout unless e
+          child_process.exec 'ipython kernelspec list --json --log-level=CRITICAL', (e, stdout, stderr) ->
+              saveKernelsToConfig stdout
+
     getRunningKernels: ->
         return _.clone(@runningKernels)
 
@@ -26,12 +48,12 @@ module.exports = KernelManager =
         else
             return language
 
-    getConfigJson: (key) ->
-        return {} unless value = atom.config.get "Hydrogen.#{key}"
+    getConfigJson: (key, _default = {}) ->
+        return _default unless value = atom.config.get "Hydrogen.#{key}"
         try
-            return JSON.parse value
+          return JSON.parse value
         catch error
-            atom.notifications.addError "Your Hydrogen config is broken: #{key}", detail: error
+          atom.notifications.addError "Your Hydrogen config is broken: #{key}", detail: error
 
     setConfigJson: (key, value, merge=false) ->
         value = _.merge @getConfigJson(key), value if merge

lib/main.coffee

@@ -13,29 +13,7 @@ WatchLanguagePicker = require './watch-language-picker'
 AutocompleteProvider = require './autocomplete-provider'
 
 module.exports = Hydrogen =
-    config:
-        languageMappings:
-            title: "Language Mappings"
-            description: 'Some packages may change the name of the grammar for
-                          a language (e.g. "Python" -> "Python Django"). That
-                          leaves Hydrogen unable to figure out what kernel to
-                          use for your code.
-
-                          This field should be valid JSON mapping a nonstandard
-                          language name to a standard one, e.g.
-
-                          {"Python Django": "python", "Ruby (Rails)": "ruby"}'
-            type: 'string'
-            default: '{}'
-        grammarToKernel:
-            description: 'JSON mappings between specific kernel and a
-                          language/grammar. This value is updated automatically
-                          by the "switch kernel" command. If you switch from
-                          python2 to python3, python3 will be used the next time
-                          you open a Python file. You probably shouldn\'t
-                          change this by hand.'
-            type: 'string'
-            default: '{}'
+    config: require './config'
 
 
     subscriptions: null
@@ -57,6 +35,7 @@ module.exports = Hydrogen =
             'hydrogen:select-watch-kernel': => @showWatchLanguagePicker()
             'hydrogen:add-watch': => @watchSidebar.addWatchFromEditor()
             'hydrogen:remove-watch': => @watchSidebar.removeWatch()
+            'hydrogen:update-kernels': -> KernelManager.updateKernels()
 
         @subscriptions.add atom.commands.add 'atom-workspace',
             'hydrogen:clear-results': => @clearResultBubbles()