Make output placeholders like json.output index-able by name.

recipe_modules/json/api.py

Index: recipe_modules/json/api.py
diff --git a/recipe_modules/json/api.py b/recipe_modules/json/api.py
index e65e3135d723d3313bddedc52cb6340efa9f101c..4c8b3ce0aac175cdda704981a6a1e7b732a72001 100644
--- a/recipe_modules/json/api.py
+++ b/recipe_modules/json/api.py
@@ -27,10 +27,10 @@ class JsonOutputPlaceholder(recipe_util.Placeholder):
   JSON document, which will be set as the json.output for that step in the
   step_history OrderedDict passed to your recipe generator.
   """
-  def __init__(self, api, add_json_log):
-    self.raw = api.m.raw_io.output('.json')
+  def __init__(self, api, add_json_log, id=id):

[iannucci, 2016/03/10 03:17:42]

we should use something other than 'id', which is a python builtin (yeah I know,
it's a really crummy builtin function name).  Maybe just 'name'?

[stgao, 2016/03/10 20:34:23]

Sounds good.

Note: PlaceHolder already has a property "name". Will add this as a prefix to
it.

+    self.raw = api.m.raw_io.output('.json', id=id)
     self.add_json_log = add_json_log
-    super(JsonOutputPlaceholder, self).__init__()
+    super(JsonOutputPlaceholder, self).__init__(id=id)
 
   @property
   def backing_file(self):
@@ -54,7 +54,10 @@ class JsonOutputPlaceholder(recipe_util.Placeholder):
       pass
 
     if self.add_json_log:
-      key = self.name + ('' if valid else ' (invalid)')
+      # Use the combination of id and name to differentiate multiple
+      # json.outputs in the same step. Otherwise, only the last one shows up
+      # as the log.
+      key = self.id_name + ('' if valid else ' (invalid)')
       with contextlib.closing(recipe_util.StringListIO()) as listio:
         json.dump(ret, listio, indent=2, sort_keys=True)
       presentation.logs[key] = listio.lines
@@ -102,17 +105,17 @@ class JsonApi(recipe_api.RecipeApi):
       return False
 
   @recipe_util.returns_placeholder
-  def input(self, data):
+  def input(self, data, id=None):
     """A placeholder which will expand to a file path containing <data>."""
-    return self.m.raw_io.input(self.dumps(data), '.json')
+    return self.m.raw_io.input(self.dumps(data), '.json', id=id)
 
   @recipe_util.returns_placeholder
-  def output(self, add_json_log=True):
+  def output(self, add_json_log=True, id=None):
     """A placeholder which will expand to '/tmp/file'."""
-    return JsonOutputPlaceholder(self, add_json_log)
+    return JsonOutputPlaceholder(self, add_json_log, id=id)
 
   # TODO(you): This method should be in the `file` recipe_module
-  def read(self, name, path, add_json_log=True, **kwargs):
+  def read(self, name, path, add_json_log=True, id=None, **kwargs):
     """Returns a step that reads a JSON file."""
     return self.m.python.inline(
         name,
@@ -121,7 +124,7 @@ class JsonApi(recipe_api.RecipeApi):
         import sys
         shutil.copy(sys.argv[1], sys.argv[2])
         """,
-        args=[path, self.output(add_json_log=add_json_log)],
+        args=[path, self.output(add_json_log=add_json_log, id=id)],
         add_python_log=False,
         **kwargs
     )