Some improvements

local/variables/package.yaml

@@ -1,5 +1,5 @@
 ---
 major: 1
-minor: 2
+minor: 3
 patch: 0
 entry: rcmpy

rcmpy/commands/apply.py

@@ -21,20 +21,20 @@ def apply_env(args: _Namespace, env: Environment) -> int:
 
     result = 0
 
+    is_new = env.state.is_new()
+
     for file in env.config.files:
         # Check if a template is found for this file.
         if file.template not in env.templates_by_name:
             result += 1
             env.logger.error("Template '%s' not found!", file.template)
             continue
 
-        if not file.platform:
+        if not file.evaluate(env.env_data):
             continue
 
-        is_new = env.state.is_new()
-
         # Check if this file has any updated templates.
-        if args.force or is_new or env.is_updated(file):
+        if args.force or is_new or not file.present or env.is_updated(file):
             template = env.templates_by_name[file.template]
 
             # If a template doesn't require rendering, use it as-is.
@@ -44,7 +44,7 @@ def apply_env(args: _Namespace, env: Environment) -> int:
                 # Render the template to the build directory.
                 source = env.build.joinpath(file.template)
                 with source.open("w") as path_fd:
-                    path_fd.write(template.template.render(env.state.configs))
+                    path_fd.write(template.template.render(env.template_data))
                     env.logger.info("Rendered '%s'.", rel(source))
 
             # Update the output file.

rcmpy/config/__init__.py

@@ -45,6 +45,8 @@ def init(self, data: _JsonObject) -> None:
                 Path(expandvars(file["directory"])).expanduser(),
                 file.get("name", file["template"]),
                 file["link"],
+                file["executable"],
+                file["condition"],
                 set(file.get("platforms", [])),
             )
 
@@ -54,7 +56,3 @@ def init(self, data: _JsonObject) -> None:
                 self.templates.add(template)
 
             self.files.append(new)
-
-    def asdict(self) -> _JsonObject:
-        """Obtain a dictionary representing this instance."""
-        return self.data

rcmpy/config/file.py

@@ -8,13 +8,19 @@
 from pathlib import Path
 from shutil import copyfile
 import sys
-from typing import Set
+from typing import Any, Dict, Set
 
 # third-party
 from vcorelib.logging import LoggerType
 from vcorelib.paths import rel
 
 
+def set_exec_flags(path: Path) -> None:
+    """Set the executable bits, but respect the 'read' bits."""
+    mode = path.stat().st_mode
+    path.chmod(mode | ((mode & 0o444) >> 2))
+
+
 @dataclass
 class ManagedFile:
     """
@@ -28,6 +34,9 @@ class ManagedFile:
     name: str
 
     link: bool
+    executable: bool
+
+    condition: str
 
     platforms: Set[str]
 
@@ -36,11 +45,22 @@ def output(self) -> Path:
         """Get the full output path."""
         return self.directory.joinpath(self.name)
 
+    @property
+    def present(self) -> bool:
+        """Determine if this file is currently present in the file system."""
+        return self.output.is_file()
+
     @property
     def platform(self) -> bool:
         """Determine if the platform is correct for handling this file."""
         return not self.platforms or sys.platform in self.platforms
 
+    def evaluate(self, env: Dict[str, Any]) -> bool:
+        """Determine if this file should be handled."""
+        return self.platform and eval(  # pylint: disable=eval-used
+            self.condition, None, env
+        )
+
     def update_root(self, root: Path) -> None:
         """
         If the output directory is a relative path, update it to be an
@@ -68,4 +88,7 @@ def update(self, source: Path, logger: LoggerType) -> None:
         else:
             copyfile(source, output)
 
+        if self.executable:
+            set_exec_flags(output)
+
         logger.info("'%s' -> '%s'.", rel(source), rel(output))

rcmpy/data/schemas/ManagedFile.yaml

@@ -17,9 +17,20 @@ properties:
     type: boolean
     default: true
 
+  # Whether or not the file should be executable.
+  executable:
+    type: boolean
+    default: false
+
   name:
     type: string
 
+  # A string that will be evaluated for True/False and provided environment
+  # data.
+  condition:
+    type: string
+    default: "True"
+
   platforms:
     type: array
     items:

rcmpy/environment/data.py

@@ -0,0 +1,39 @@
+"""
+A module for exposing useful information from the current system to templates.
+"""
+
+# built-in
+from functools import lru_cache
+import platform
+import sys
+from typing import Any, Dict
+
+
+@lru_cache(maxsize=1)
+def system_data() -> Dict[str, Any]:
+    """Obtain useful system configuration data."""
+
+    return {
+        "sys": {
+            "base_exec_prefix": sys.base_exec_prefix,
+            "base_prefix": sys.base_prefix,
+            "byteorder": sys.byteorder,
+            "exec_prefix": sys.exec_prefix,
+            "executable": sys.executable,
+            "platform": sys.platform,
+            "prefix": sys.prefix,
+            "version": sys.version,
+        },
+        "platform": {
+            "bits": platform.architecture()[0],
+            "linkage": platform.architecture()[1],
+            "machine": platform.machine(),
+            "node": platform.node(),
+            "processor": platform.processor(),
+            "implementation": platform.python_implementation(),
+            "python_version": platform.python_version(),
+            "release": platform.release(),
+            "system": platform.system(),
+            "version": platform.version(),
+        },
+    }

rcmpy/environment/template.py

@@ -3,6 +3,7 @@
 """
 
 # built-in
+from copy import copy
 from pathlib import Path
 from typing import Dict, NamedTuple, Optional, Set, Tuple
 
@@ -15,6 +16,7 @@
 # internal
 from rcmpy.config import ManagedFile
 from rcmpy.environment.base import BaseEnvironment
+from rcmpy.environment.data import system_data
 
 
 class EnvTemplate(NamedTuple):
@@ -171,4 +173,10 @@ def _init_loaded(self) -> bool:
         self.updated_templates: Set[Path] = set()
         self.updated_template_names: Set[str] = set()
 
+        # Add additional information to template data.
+        self.env_data = system_data()
+        self.template_data = copy(self.state.configs)
+        assert "env" not in self.template_data
+        self.template_data["env"] = self.env_data
+
         return result and self._init_templates(self.config.templates)

rcmpy/state/__init__.py

@@ -53,6 +53,7 @@ def init(self, data: _JsonObject) -> None:
 
         data.setdefault("previous", {})
         self.previous: Dict[str, Any] = data["previous"]  # type: ignore
+        self.previous.setdefault("variant", "default")
 
         # Variables.
         self.variables: Dict[str, Any] = {}

tests/data/valid/scenarios/simple/rcmpy.yaml

@@ -1,12 +1,15 @@
 ---
 files:
   - template: test.txt
+    executable: true
 
   - template: dynamic.txt
     extra_templates: [a.txt, b.txt, c.txt]
+    condition: "'platform' in sys"
 
   - template: basic.txt
     link: false
+    executable: true
 
   - template: linux.txt
     platforms: [linux]