Move flask_compress dependency to extra requires.

paaschdigital · Oct 27, 2022 · 3d18085 · 3d18085
1 parent a966208
commit 3d18085
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Showing 4 changed files with 25 additions and 17 deletions.
diff --git a/dash/dash.py b/dash/dash.py
@@ -18,7 +18,6 @@
 from textwrap import dedent
 
 import flask
-from flask_compress import Compress
 
 from pkg_resources import get_distribution, parse_version
 
@@ -69,9 +68,6 @@
     _parse_query_string,
 )
 
-
-_flask_compress_version = parse_version(get_distribution("flask-compress").version)
-
 # Add explicit mapping for map files
 mimetypes.add_type("application/json", ".map", True)
 
@@ -261,6 +257,7 @@ class Dash:
     :type serve_locally: boolean
 
     :param compress: Use gzip to compress files and data served by Flask.
+        To use this option, you need to install dash[compress]
         Default ``False``
     :type compress: boolean
 
@@ -379,16 +376,6 @@ def __init__(  # pylint: disable=too-many-statements
         else:
             raise ValueError("server must be a Flask app or a boolean")
 
-        if (
-            self.server is not None
-            and not hasattr(self.server.config, "COMPRESS_ALGORITHM")
-            and _flask_compress_version >= parse_version("1.6.0")
-        ):
-            # flask-compress==1.6.0 changed default to ['br', 'gzip']
-            # and non-overridable default compression with Brotli is
-            # causing performance issues
-            self.server.config["COMPRESS_ALGORITHM"] = ["gzip"]
-
         base_prefix, routes_prefix, requests_prefix = pathname_configs(
             url_base_pathname, routes_pathname_prefix, requests_pathname_prefix
         )
@@ -540,8 +527,28 @@ def init_app(self, app=None, **kwargs):
         )
 
         if config.compress:
-            # gzip
-            Compress(self.server)
+            try:
+                # pylint: disable=import-outside-toplevel
+                from flask_compress import Compress
+
+                # gzip
+                Compress(self.server)
+
+                _flask_compress_version = parse_version(
+                    get_distribution("flask-compress").version
+                )
+
+                if not hasattr(
+                    self.server.config, "COMPRESS_ALGORITHM"
+                ) and _flask_compress_version >= parse_version("1.6.0"):
+                    # flask-compress==1.6.0 changed default to ['br', 'gzip']
+                    # and non-overridable default compression with Brotli is
+                    # causing performance issues
+                    self.server.config["COMPRESS_ALGORITHM"] = ["gzip"]
+            except ImportError as error:
+                raise ImportError(
+                    "To use the compress option, you need to install dash[compress]"
+                ) from error
 
         @self.server.errorhandler(PreventUpdate)
         def _handle_error(_):

diff --git a/requires-compress.txt b/requires-compress.txt
@@ -0,0 +1 @@
+flask-compress
diff --git a/requires-install.txt b/requires-install.txt
@@ -1,5 +1,4 @@
 Flask>=1.0.4
-flask-compress
 plotly>=5.0.0
 dash_html_components==2.0.0
 dash_core_components==2.0.0

diff --git a/setup.py b/setup.py
@@ -33,6 +33,7 @@ def read_req_file(req_type):
         "testing": read_req_file("testing"),
         "celery": read_req_file("celery"),
         "diskcache": read_req_file("diskcache"),
+        "compress": read_req_file("compress"),
     },
     entry_points={
         "console_scripts": [