✨ Add low-setup usage

This adds the ability to use moban in an ad-hoc manner
without a config file. This also adds environment variables
as a fallback data source if the default/specified data files
do not exist.

Closes moremoban#133

moban/main.py

@@ -152,7 +152,6 @@ def handle_command_line(options):
     """
     act upon command options
     """
-    options = merge(options, constants.DEFAULT_OPTIONS)
     if options[constants.LABEL_TEMPLATE] is None:
         raise exceptions.NoTemplate(constants.ERROR_NO_TEMPLATE)
     engine = plugins.ENGINES.get_engine(

moban/mobanfile.py

@@ -37,7 +37,6 @@ def find_default_moban_file():
 
 def handle_moban_file_v1(moban_file_configurations, command_line_options):
     merged_options = None
-    target = extract_target(command_line_options)
     if constants.LABEL_CONFIG in moban_file_configurations:
         merged_options = merge(
             command_line_options,
@@ -52,12 +51,18 @@ def handle_moban_file_v1(moban_file_configurations, command_line_options):
     if requires:
         handle_requires(requires)
 
+    target = extract_target(command_line_options)
     targets = moban_file_configurations.get(constants.LABEL_TARGETS)
     if targets:
         if target:
-            # if command line option exists, append its template to targets
-            # issue 30
-            targets += target
+            template = target[0]['template']
+            if any(template in t.values() for t in targets):
+                # If template from CLI is in targets from custom moban file,
+                # update only the template specifed by CLI
+                targets = [t for t in targets if template in t.values()]
+            else:
+                # Otherwise, append to targets (issue 30)
+                targets += target
         number_of_templated_files = handle_targets(merged_options, targets)
     else:
         number_of_templated_files = 0

moban/plugins.py

@@ -46,7 +46,15 @@ def number_of_templated_files(self):
         return self.templated_count
 
     def render_to_file(self, template_file, data_file, output_file):
-        data = self.context.get_data(data_file)
+        try:
+            data = self.context.get_data(data_file)
+        except OSError as exception:
+            # If data file doesn't exist:
+            # 1. Alert the user of their (potential) mistake
+            # 2. Attempt to use environment vars as data
+            reporter.report_error_message(exception)
+            reporter.report_using_env_vars()
+            data = os.environ
         template = self.engine.get_template(template_file)
         template_abs_path = utils.get_template_path(
             self.template_dirs, template_file
@@ -89,7 +97,15 @@ def _render_with_finding_template_first(self, template_file_index):
                 self.template_dirs, template_file
             )
             for (data_file, output) in data_output_pairs:
-                data = self.context.get_data(data_file)
+                try:
+                    data = self.context.get_data(data_file)
+                except OSError as exception:
+                    # If data file doesn't exist:
+                    # 1. Alert the user of their (potential) mistake
+                    # 2. Attempt to use environment vars as data
+                    reporter.report_error_message(exception)
+                    reporter.report_using_env_vars()
+                    data = os.environ
                 flag = self.apply_template(
                     template_abs_path, template, data, output
                 )
@@ -100,7 +116,15 @@ def _render_with_finding_template_first(self, template_file_index):
 
     def _render_with_finding_data_first(self, data_file_index):
         for (data_file, template_output_pairs) in data_file_index.items():
-            data = self.context.get_data(data_file)
+            try:
+                data = self.context.get_data(data_file)
+            except OSError as exception:
+                # If data file doesn't exist:
+                # 1. Alert the user of their (potential) mistake
+                # 2. Attempt to use environment vars as data
+                reporter.report_error_message(exception)
+                reporter.report_using_env_vars()
+                data = os.environ
             for (template_file, output) in template_output_pairs:
                 template = self.engine.get_template(template_file)
                 template_abs_path = utils.get_template_path(

moban/reporter.py

@@ -12,6 +12,7 @@
 MESSAGE_COPIED_ALL = "Copied {0} files."
 MESSAGE_PULLING_REPO = "Updating {0}..."
 MESSAGE_CLONING_REPO = "Cloning {0}..."
+MESSAGE_USING_ENV_VARS = "Attempting to use environment vars as data..."
 
 
 def report_templating(source_file, destination_file):
@@ -89,6 +90,10 @@ def report_git_clone(repo):
     print(MESSAGE_CLONING_REPO.format(colored_repo))
 
 
+def report_using_env_vars():
+    print(crayons.yellow(MESSAGE_USING_ENV_VARS, bold=True))
+
+
 def _format_single(message, count):
     if count == 1:
         return message.replace("files", "file")