build fixes

4 files changed, 106 insertions, 24 deletions

diff --git a/README.md b/README.md
index 85cb68f..eee19f7 100644
--- a/README.md
+++ b/README.md
@@ -7,10 +7,38 @@ that information in a BSFS storage.
 
 ## Installation
 
-You can install BSIE via pip:
+You can install BSIE via pip. BSIE comes with support for various file formats.
+For this, it needs to install many external packages. BSIE lets you control
+which of these you want to install. Note that if you choose to not install
+support for some file types, BSIE will show a warning and skip them.
+All other formats will be processed normally.
+
+To install only the minimally required software, use:
 
     $ pip install --extra-index-url https://pip.bsfs.io bsie
 
+To install all dependencies, use the following shortcut:
+
+    $ pip install --extra-index-url https://pip.bsfs.io bsie[all]
+
+To install a subset of all dependencies, modify the extras part (``[image, preview]``)
+of the follwing command to your liking:
+
+    $ pip install --extra-index-url https://pip.bsfs.io bsie[image,preview]
+
+Currently, BSIE providesthe following extra flags:
+
+* image: Read data from image files.
+  Note that you may also have to install ``exiftool`` through your system's
+  package manager (e.g. ``sudo apt install exiftool``).
+* preview: Create previews from a variety of files.
+  Note that support for various file formats also depends on what
+  system packages you've installed. You should at least install ``imagemagick``
+  through your system's package manager (e.g. ``sudo apt install imagemagick``).
+  See [Preview Generator](https://github.com/algoo/preview-generator) for
+  more detailed instructions.
+* features: Extract feature vectors from images.
+
 
 ## Development
 
@@ -23,9 +51,15 @@ Install bsie as editable from the git repository:
 
     $ git clone https://git.bsfs.io/bsie.git
     $ cd bsie
-    $ pip install -e .
+    $ pip install -e .[all]
+
+If you want to develop (*dev*), run the tests (*test*), edit the
+documentation (*doc*), or build a distributable (*build*),
+install bsfs with the respective extras (in addition to file format extras):
 
-Install the following additional packages besides BSIE:
+    $ pip install -e .[dev,doc,build,test]
+
+Or, you can manually install the following packages besides BSIE:
 
     $ pip install coverage mypy pylint
     $ pip install rdflib requests types-PyYAML
@@ -52,4 +86,3 @@ To build the documentation, run the following commands from the **doc folder**:
     $ make html
     $ xdg-open build/html/index.html
 
-
diff --git a/bsie/utils/loading.py b/bsie/utils/loading.py
index 3c5c7c1..58202d1 100644
--- a/bsie/utils/loading.py
+++ b/bsie/utils/loading.py
@@ -22,14 +22,14 @@ def safe_load(module_name: str, class_name: str):
         module = importlib.import_module(module_name)
     except Exception as err:
         # cannot import module
-        raise errors.LoaderError(f'cannot load module {module_name}') from err
+        raise errors.LoaderError(f'cannot load module {module_name} ({err})') from err
 
     try:
         # get the class from the module
         cls = getattr(module, class_name)
     except Exception as err:
         # cannot find the class
-        raise errors.LoaderError(f'cannot load class {class_name} from module {module_name}') from err
+        raise errors.LoaderError(f'cannot load class {class_name} from module {module_name} ({err})') from err
 
     return cls
 
diff --git a/doc/source/installation.rst b/doc/source/installation.rst
index b634457..ee6fadb 100644
--- a/doc/source/installation.rst
+++ b/doc/source/installation.rst
@@ -2,15 +2,39 @@
 Installation
 ============
 
-Installation
-------------
+You can install *bsie* via pip. BSIE comes with support for various file formats.
+For this, it needs to install many external packages. BSIE lets you control
+which of these you want to install. Note that if you choose to not install
+support for some file types, BSIE will show a warning and skip them.
+All other formats will be processed normally.
+It is recommended to install *bsie* in a virtual environment (via ``virtualenv``).
 
-Install *bsie* via pip::
+To install only the minimally required software, use::
 
     pip install --extra-index-url https://pip.bsfs.io bsie
 
-This installs the `bsie` python package as well as the `bsie.app` command.
-It is recommended to install *bsie* in a virtual environment (via `virtualenv`).
+To install all dependencies, use the following shortcut::
+
+    pip install --extra-index-url https://pip.bsfs.io bsie[all]
+
+To install a subset of all dependencies, modify the extras part (``[image, preview]``)
+of the follwing command to your liking::
+
+    pip install --extra-index-url https://pip.bsfs.io bsie[image,preview]
+
+Currently, BSIE providesthe following extra flags:
+
+* image: Read data from image files.
+  Note that you may also have to install ``exiftool`` through your system's
+  package manager (e.g. ``sudo apt install exiftool``).
+* preview: Create previews from a variety of files.
+  Note that support for various file formats also depends on what
+  system packages you've installed. You should at least install ``imagemagick``
+  through your system's package manager (e.g. ``sudo apt install imagemagick``).
+  See `Preview Generator <https://github.com/algoo/preview-generator>`_ for
+  more detailed instructions.
+* features: Extract feature vectors from images.
+
 
 
 License
diff --git a/setup.py b/setup.py
index 43bdd32..b1f5b2c 100644
--- a/setup.py
+++ b/setup.py
@@ -2,6 +2,28 @@
 from setuptools import setup, find_packages
 import os
 
+extras = {
+    # NOTE: an 'all' extra is added automatically
+    'features': [
+        # image feature extractors
+        'numpy',
+        ],
+    'preview': [
+        # preview readers
+        'preview_generator', # also depends on some system packages
+        'pillow',
+        'rawpy',
+        ],
+    'image': [
+        # image readers
+        'pillow',
+        'rawpy',
+        # exif reader
+        'pyexiv2',
+        ],
+    }
+
+
 setup(
     # package metadata
     name='bsie',
@@ -9,14 +31,15 @@ setup(
     author='Matthias Baumgartner',
     author_email='dev@bsfs.io',
     description='Extract information from files and store them in a BSFS.',
-    long_description=open(os.path.join(os.path.dirname(__file__), 'README')).read(),
+    long_description=open(os.path.join(os.path.dirname(__file__), 'README.md')).read(),
     license='BSD',
     license_files=('LICENSE', ),
     url='https://www.bsfs.io/bsie/',
     download_url='https://pip.bsfs.io',
 
     # packages
-    packages=[p for p in find_packages() if p.startswith('bsie')],
+    packages=find_packages(include=['bsie']),
+    package_dir={'bsie': 'bsie'},
     # data files are included if mentioned in MANIFEST.in
     include_package_data=True,
 
@@ -31,18 +54,20 @@ setup(
     python_requires=">=3.7",
     install_requires=(
         'bsfs',
-        # filematcher
         'pyparsing',
         'python-magic',
+        'pyyaml',
         ),
-    extra_require=(
-        # image feature extractors
-        'numpy',
-        # preview reader
-        'preview_generator', # also depends on some system packages
-        # image reader
-        'pillow',
-        'rawpy',
-        )
-)
+    extras_require=dict(
+        # development targets
+        build=['build'],
+        dev=['coverage', 'mypy', 'pylint'],
+        doc=['sphinx', 'sphinx-copybutton', 'furo'],
+        test=['rdflib', 'requests', 'types-PyYAML'],
+        # add 'all'
+        all=list({pkg for ext in extras.values() for pkg in ext}),
+        # add extras
+        **extras
+        ),
+    )