Add 'skip' option to crawlers

CHANGELOG.md

@@ -22,6 +22,9 @@ ambiguous situations.
 
 ## Unreleased
 
+### Added
+- `skip` option for crawlers
+
 ### Changed
 - Use `/` instead of `\` as path separator for (regex) rules on Windows
 

CONFIG.md

@@ -49,6 +49,9 @@ see the type's [documentation](#crawler-types) below. The following options are
 common to all crawlers:
 
 - `type`: The available types are specified in [this section](#crawler-types).
+- `skip`: Whether the crawler should be skipped during normal execution. The
+  crawler can still be executed manually using the `--crawler` or `-C` flags.
+  (Default: `no`)
 - `output_dir`: The directory the crawler synchronizes files to. A crawler will
   never place any files outside of this directory. (Default: the crawler's name)
 - `redownload`: When to download a file that is already present locally.

PFERD/auth/authenticator.py

@@ -13,7 +13,11 @@ class AuthError(Exception):
 
 
 class AuthSection(Section):
-    pass
+    def type(self) -> str:
+        value = self.s.get("type")
+        if value is None:
+            self.missing_value("type")
+        return value
 
 
 class Authenticator(ABC):

PFERD/crawl/__init__.py

@@ -3,7 +3,7 @@ from typing import Callable, Dict
 
 from ..auth import Authenticator
 from ..config import Config
-from .crawler import Crawler, CrawlError  # noqa: F401
+from .crawler import Crawler, CrawlError, CrawlerSection  # noqa: F401
 from .ilias import KitIliasWebCrawler, KitIliasWebCrawlerSection
 from .local_crawler import LocalCrawler, LocalCrawlerSection
 

PFERD/crawl/crawler.py

@@ -132,6 +132,15 @@ class DownloadToken(ReusableAsyncContextManager[Tuple[ProgressBar, FileSink]]):
 
 
 class CrawlerSection(Section):
+    def type(self) -> str:
+        value = self.s.get("type")
+        if value is None:
+            self.missing_value("type")
+        return value
+
+    def skip(self) -> bool:
+        return self.s.getboolean("skip", fallback=False)
+
     def output_dir(self, name: str) -> Path:
         # TODO Use removeprefix() after switching to 3.9
         if name.startswith("crawl:"):

PFERD/pferd.py

@@ -3,9 +3,9 @@ from typing import Dict, List, Optional
 
 from rich.markup import escape
 
-from .auth import AUTHENTICATORS, Authenticator, AuthError
+from .auth import AUTHENTICATORS, Authenticator, AuthError, AuthSection
 from .config import Config, ConfigOptionError
-from .crawl import CRAWLERS, Crawler, CrawlError, KitIliasWebCrawler
+from .crawl import CRAWLERS, Crawler, CrawlError, CrawlerSection, KitIliasWebCrawler
 from .logging import log
 from .utils import fmt_path
 
@@ -26,19 +26,22 @@ class Pferd:
         self._authenticators: Dict[str, Authenticator] = {}
         self._crawlers: Dict[str, Crawler] = {}
 
-    def _find_crawlers_to_run(self, config: Config, cli_crawlers: Optional[List[str]]) -> List[str]:
-        log.explain_topic("Deciding which crawlers to run")
-        crawl_sections = [name for name, _ in config.crawl_sections()]
+    def _find_config_crawlers(self, config: Config) -> List[str]:
+        crawl_sections = []
 
-        if cli_crawlers is None:
-            log.explain("No crawlers specified on CLI")
-            log.explain("Running all crawlers specified in config")
-            return crawl_sections
+        for name, section in config.crawl_sections():
+            if CrawlerSection(section).skip():
+                log.explain(f"Skipping {name!r}")
+            else:
+                crawl_sections.append(name)
 
+        return crawl_sections
+
+    def _find_cli_crawlers(self, config: Config, cli_crawlers: List[str]) -> List[str]:
         if len(cli_crawlers) != len(set(cli_crawlers)):
             raise PferdLoadError("Some crawlers were selected multiple times")
 
-        log.explain("Crawlers specified on CLI")
+        crawl_sections = [name for name, _ in config.crawl_sections()]
 
         crawlers_to_run = []  # With crawl: prefix
         unknown_names = []  # Without crawl: prefix
@@ -62,10 +65,22 @@ class Pferd:
 
         return crawlers_to_run
 
+    def _find_crawlers_to_run(self, config: Config, cli_crawlers: Optional[List[str]]) -> List[str]:
+        log.explain_topic("Deciding which crawlers to run")
+
+        if cli_crawlers is None:
+            log.explain("No crawlers specified on CLI")
+            log.explain("Running crawlers specified in config")
+            return self._find_config_crawlers(config)
+        else:
+            log.explain("Crawlers specified on CLI")
+            return self._find_cli_crawlers(config, cli_crawlers)
+
     def _load_authenticators(self) -> None:
         for name, section in self._config.auth_sections():
             log.print(f"[bold bright_cyan]Loading[/] {escape(name)}")
-            auth_type = section.get("type")
+
+            auth_type = AuthSection(section).type()
             authenticator_constructor = AUTHENTICATORS.get(auth_type)
             if authenticator_constructor is None:
                 raise ConfigOptionError(name, "type", f"Unknown authenticator type: {auth_type!r}")
@@ -80,7 +95,7 @@ class Pferd:
         for name, section in self._config.crawl_sections():
             log.print(f"[bold bright_cyan]Loading[/] {escape(name)}")
 
-            crawl_type = section.get("type")
+            crawl_type = CrawlerSection(section).type()
             crawler_constructor = CRAWLERS.get(crawl_type)
             if crawler_constructor is None:
                 raise ConfigOptionError(name, "type", f"Unknown crawler type: {crawl_type!r}")