wehub-resource-sync
75 lines
2.4 KiB
Python
75 lines
2.4 KiB
Python
"""Centralized loader for optional third-party deps (weasyprint, pypdf, PyMuPDF).
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build.py previously had inline `from weasyprint import HTML` try/except blocks
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with duplicated install hints; this module collapses those into one resolver
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each so the import error message stays consistent and the WeasyPrint runtime
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is configured once at the import call site.
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"""
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from __future__ import annotations
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import sys
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from shared import configure_weasyprint_runtime
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# On Linux, WeasyPrint links against cairo / pango / harfbuzz at runtime; a bare
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# `pip install weasyprint` succeeds but then fails to load with a cryptic
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# "cannot load library 'libgobject-2.0'" until the native libs are present. Spell
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# them out so the error message is actionable on a fresh Linux box.
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_LINUX_NATIVE_LIBS = (
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"Linux also needs native libs: "
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"sudo apt-get install -y libcairo2 libpango-1.0-0 libpangoft2-1.0-0 libharfbuzz0b "
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"(Debian/Ubuntu), or `sudo dnf install cairo pango harfbuzz` (Fedora/RHEL)"
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)
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WEASYPRINT_INSTALL_HINT = "pip install weasyprint pypdf --break-system-packages"
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if sys.platform.startswith("linux"):
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WEASYPRINT_INSTALL_HINT = f"{WEASYPRINT_INSTALL_HINT}. {_LINUX_NATIVE_LIBS}"
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PYMUPDF_INSTALL_HINT = "pip install pymupdf --break-system-packages"
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class MissingDepError(RuntimeError):
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"""Raised when an optional dependency is requested but not installed."""
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def require_weasyprint_html():
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"""Return the weasyprint.HTML class, configuring native libs first."""
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configure_weasyprint_runtime()
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try:
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from weasyprint import HTML
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return HTML
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except ImportError as exc:
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raise MissingDepError(
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f"missing weasyprint. {WEASYPRINT_INSTALL_HINT}"
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) from exc
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def _require_pypdf_attr(name: str):
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try:
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import pypdf
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except ImportError as exc:
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raise MissingDepError(
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f"missing pypdf. {WEASYPRINT_INSTALL_HINT}"
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) from exc
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return getattr(pypdf, name)
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def require_pypdf_reader():
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"""Return the pypdf.PdfReader class."""
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return _require_pypdf_attr("PdfReader")
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def require_pypdf_writer():
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"""Return the pypdf.PdfWriter class."""
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return _require_pypdf_attr("PdfWriter")
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def require_pymupdf():
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"""Return the PyMuPDF module (imported as fitz)."""
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try:
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import fitz
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return fitz
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except ImportError as exc:
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raise MissingDepError(
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f"missing PyMuPDF. {PYMUPDF_INSTALL_HINT}"
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) from exc
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