🎨 Break render into separate functions

hyperglass/render/webassets.py

@@ -0,0 +1,77 @@
+"""
+Renders Jinja2 & Sass templates for use by the front end application
+"""
+# Standard Library Imports
+import json
+import subprocess
+from pathlib import Path
+
+# Third Party Imports
+import jinja2
+from logzero import logger
+
+# Project Imports
+from hyperglass.configuration import logzero_config  # noqa: F401
+from hyperglass.configuration import params
+from hyperglass.exceptions import HyperglassError
+
+# Module Directories
+working_directory = Path(__file__).resolve().parent
+hyperglass_root = working_directory.parent
+file_loader = jinja2.FileSystemLoader(str(working_directory))
+env = jinja2.Environment(
+    loader=file_loader, autoescape=True, extensions=["jinja2.ext.autoescape"]
+)
+
+
+def render_theme():
+    """Renders Jinja2 template to Sass file"""
+    rendered_theme_file = hyperglass_root.joinpath("static/theme.sass")
+    try:
+        template = env.get_template("templates/theme.sass.j2")
+        rendered_theme = template.render(params.branding)
+        with rendered_theme_file.open(mode="w") as theme_file:
+            theme_file.write(rendered_theme)
+    except jinja2.exceptions as theme_error:
+        logger.error(f"Error rendering theme: {theme_error}")
+        raise HyperglassError(theme_error)
+
+
+def build_assets():
+    """Builds, bundles, and minifies Sass/CSS/JS web assets"""
+    proc = subprocess.Popen(
+        ["yarn", "--silent", "--emoji", "false", "--json", "--no-progress", "build"],
+        cwd=hyperglass_root.joinpath("static"),
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+    )
+    try:
+        stdout, stderr = proc.communicate(timeout=15)
+    except subprocess.TimeoutExpired:
+        proc.kill()
+        stdout, stderr = proc.communicate()
+    output_out = json.loads(stdout.decode("utf-8").split("\n")[0])
+    if proc.returncode != 0:
+        output_error = json.loads(stderr.decode("utf-8").strip("\n"))
+        logger.error(output_error["data"])
+        raise HyperglassError(
+            f'Error building web assets with script {output_out["data"]}:'
+            f'{output_error["data"]}'
+        )
+    logger.debug(f'Built web assets with script {output_out["data"]}')
+
+
+def render_assets():
+    """Controller function for rendering sass theme elements and building web assets"""
+    try:
+        logger.debug("Rendering theme elements...")
+        render_theme()
+        logger.debug("Rendered theme elements")
+    except HyperglassError as theme_error:
+        raise HyperglassError(theme_error)
+    try:
+        logger.debug("Building web assets...")
+        build_assets()
+        logger.debug("Built web assets")
+    except HyperglassError as assets_error:
+        raise HyperglassError(assets_error)