check language (#521)

* check language * language tests * Update drawBot/drawBotDrawingTools.py Co-authored-by: Just van Rossum <justvanrossum@gmail.com> --------- Co-authored-by: Just van Rossum <justvanrossum@gmail.com>
typemytype · Dec 5, 2023 · 567a1b7 · 567a1b7
1 parent 08b62c2
commit 567a1b7
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Showing 3 changed files with 55 additions and 5 deletions.
diff --git a/drawBot/drawBotDrawingTools.py b/drawBot/drawBotDrawingTools.py
@@ -17,7 +17,7 @@
 from .context.tools import openType
 from .context.tools import drawBotbuiltins
 
-from .misc import DrawBotError, warnings, VariableController, optimizePath, isPDF, isEPS, isGIF, transformationAtCenter, clearMemoizeCache
+from .misc import DrawBotError, warnings, VariableController, optimizePath, isPDF, isEPS, isGIF, transformationAtCenter, clearMemoizeCache, validateLanguageCode
 
 
 def _getmodulecontents(module, names=None):
@@ -1516,8 +1516,9 @@ def tabs(self, *tabs):
     def language(self, language):
         """
         Set the preferred language as language tag or None to use the default language.
-
-        Support is depending on local OS.
+        A language tag might be a [iso639-2 or iso639-1](https://www.loc.gov/standards/iso639-2/php/English_list.php)
+        code or a locale identifier supported by local OS.
+        A warning will be issued if the language tag is not supported.
 
         `language()` will activate the `locl` OpenType features, if supported by the current font.
 
@@ -1541,6 +1542,8 @@ def language(self, language):
             # darw the text again with a language set
             textBox(word, box)
         """
+        if not validateLanguageCode(language):
+            warnings.warn(f"Language '{language}' is not available.")
         self._dummyContext.language(language)
         self._checkLanguageHyphenation()
         self._addInstruction("language", language)
@@ -1557,7 +1560,7 @@ def _checkLanguageHyphenation(self):
         if language and self._dummyContext._state.hyphenation:
             locale = CoreText.CFLocaleCreate(None, language)
             if not CoreText.CFStringIsHyphenationAvailableForLocale(locale):
-                warnings.warn("Language '%s' has no hyphenation available." % language)
+                warnings.warn(f"Language '{language}' has no hyphenation available.")
 
     def openTypeFeatures(self, *args, **features):
         """

diff --git a/drawBot/misc.py b/drawBot/misc.py
@@ -197,6 +197,25 @@ def nsStringLength(s):
     return len(s.encode("utf-16-be")) // 2
 
 
+# ===================
+# = language tools  =
+# ===================
+
+def canonicalLocaleCode(localeCode):
+    parsedLoc = AppKit.NSLocale.componentsFromLocaleIdentifier_(localeCode)
+    parts = [
+        parsedLoc[AppKit.kCFLocaleLanguageCode],
+        parsedLoc.get(AppKit.kCFLocaleScriptCode),
+        parsedLoc.get(AppKit.kCFLocaleCountryCode),
+    ]
+    return "_".join(part for part in parts if part)
+
+
+def validateLanguageCode(localeCode):
+    localeCode = canonicalLocaleCode(localeCode)
+    return localeCode in AppKit.NSLocale.availableLocaleIdentifiers()
+
+
 # ============
 # = warnings =
 # ============

diff --git a/tests/testMisc.py b/tests/testMisc.py
@@ -7,7 +7,7 @@
 from collections import OrderedDict
 from fontTools.ttLib import TTFont
 import drawBot
-from drawBot.misc import DrawBotError, warnings
+from drawBot.misc import DrawBotError, warnings, validateLanguageCode
 from drawBot.scriptTools import ScriptRunner
 from testSupport import StdOutCollector, testDataDir
 
@@ -394,6 +394,34 @@ def test_remap(self):
         assert drawBot.remap(25, 10, 20, 30, 50) == 60
         assert drawBot.remap(25, 10, 20, 30, 50, clamp=True) == 50
 
+    def test_validateLanguageCode(self):
+        expectedLanguageValidation = [
+            ("ab", False),
+            ("abk", False),
+            ("abz", False),
+            ("AB", False),
+            ("af", True),
+            ("afr", True),
+            ("af_NA", True),
+            ("afr_NA", True),
+            ("af_ZZ", False),
+            ("afr_ZZ", False),
+            ("en-us", True),
+            ("en_us", True),
+            ("EN-US", True),
+            ("en-zz", False),
+            ("sr_Cyrl_ME", True),
+            ("en", True),
+        ]
+        for language, expectedValue in expectedLanguageValidation:
+            assert validateLanguageCode(language) == expectedValue
+
+            with StdOutCollector(captureStdErr=True) as output:
+                drawBot.language(language)
+            if expectedValue:
+                assert output.lines() == []
+            else:
+                assert output.lines() == [f"*** DrawBot warning: Language '{language}' is not available. ***"]
 
 
 def _roundInstanceLocations(instanceLocations):