Two new formatter functions: language_codes and language_strings.

src/calibre/manual/template_lang.rst

@@ -128,6 +128,8 @@ The functions available are listed below. Note that the definitive documentation
     * ``human_readable()`` -- expects the value to be a number and returns a string representing that number in KB, MB, GB, etc.
     * ``ifempty(text)``	-- if the field is not empty, return the value of the field. Otherwise return `text`.
     * ``in_list(separator, pattern, found_val, not_found_val)`` -- interpret the field as a list of items separated by `separator`, comparing the `pattern` against each value in the list. If the pattern matches a value, return `found_val`, otherwise return `not_found_val`.
+    * ``language_codes(lang_strings)`` -- return the language codes for the strings passed in `lang_strings`. The strings must be in the language of the current locale. `Lang_strings` is a comma-separated list.
+    * ``language_strings(lang_codes, localize)`` -- return the strings for the language codes passed in `lang_codes`. If `localize` is zero, return the strings in English. If localize is not zero, return the strings in the language of the current locale. `Lang_codes` is a comma-separated list.
     * ``list_item(index, separator)`` -- interpret the field as a list of items separated by `separator`, returning the `index`th item. The first item is number zero. The last item can be returned using `list_item(-1,separator)`. If the item is not in the list, then the empty value is returned. The separator has the same meaning as in the `count` function.
     * ``re(pattern, replacement)`` -- return the field after applying the regular expression. All instances of `pattern` are replaced with `replacement`. As in all of |app|, these are python-compatible regular expressions.
     * ``shorten(left chars, middle text, right chars)`` -- Return a shortened version of the field, consisting of `left chars` characters from the beginning of the field, followed by `middle text`, followed by `right chars` characters from the end of the string. `Left chars` and `right chars` must be integers. For example, assume the title of the book is `Ancient English Laws in the Times of Ivanhoe`, and you want it to fit in a space of at most 15 characters. If you use ``{title:shorten(9,-,5)}``, the result will be `Ancient E-nhoe`. If the field's length is less than ``left chars`` + ``right chars`` + the length of ``middle text``, then the field will be used intact. For example, the title `The Dome` would not be changed.

src/calibre/utils/formatter_functions.py

@@ -14,7 +14,7 @@ from calibre import human_readable
 from calibre.utils.titlecase import titlecase
 from calibre.utils.icu import capitalize, strcmp, sort_key
 from calibre.utils.date import parse_date, format_date, now, UNDEFINED_DATE
-
+from calibre.utils.localization import calibre_langcode_to_name, canonicalize_lang
 
 class FormatterFunctions(object):
 
@@ -968,7 +968,7 @@ class BuiltinListSort(BuiltinFormatterFunction):
 class BuiltinToday(BuiltinFormatterFunction):
     name = 'today'
     arg_count = 0
-    category = 'Date _functions'
+    category = 'Date functions'
     __doc__ = doc = _('today() -- '
             'return a date string for today. This value is designed for use in '
             'format_date or days_between, but can be manipulated like any '
@@ -979,7 +979,7 @@ class BuiltinToday(BuiltinFormatterFunction):
 class BuiltinDaysBetween(BuiltinFormatterFunction):
     name = 'days_between'
     arg_count = 2
-    category = 'Date _functions'
+    category = 'Date functions'
     __doc__ = doc = _('days_between(date1, date2) -- '
             'return the number of days between date1 and date2. The number is '
             'positive if date1 is greater than date2, otherwise negative. If '
@@ -998,6 +998,45 @@ class BuiltinDaysBetween(BuiltinFormatterFunction):
         i = d1 - d2
         return str('%d.%d'%(i.days, i.seconds/8640))
 
+class BuiltinLanguageStrings(BuiltinFormatterFunction):
+    name = 'language_strings'
+    arg_count = 2
+    category = 'Get values from metadata'
+    __doc__ = doc = _('language_strings(lang_codes, localize) -- '
+            'return the strings for the language codes passed in lang_codes. '
+            'If localize is zero, return the strings in English. If '
+            'localize is not zero, return the strings in the language of '
+            'the current locale. Lang_codes is a comma-separated list.')
+    def evaluate(self, formatter, kwargs, mi, locals, lang_codes, localize):
+        retval = []
+        for c in [c.strip() for c in lang_codes.split(',') if c.strip()]:
+            try:
+                n = calibre_langcode_to_name(c, localize != '0')
+                if n:
+                    retval.append(n)
+            except:
+                pass
+        return ', '.join(retval)
+
+class BuiltinLanguageCodes(BuiltinFormatterFunction):
+    name = 'language_codes'
+    arg_count = 1
+    category = 'Get values from metadata'
+    __doc__ = doc = _('language_codes(lang_strings) -- '
+            'return the language codes for the strings passed in lang_strings. '
+            'The strings must be in the language of the current locale. '
+            'Lang_strings is a comma-separated list.')
+    def evaluate(self, formatter, kwargs, mi, locals, lang_strings):
+        retval = []
+        for c in [c.strip() for c in lang_strings.split(',') if c.strip()]:
+            try:
+                cv = canonicalize_lang(c)
+                if cv:
+                    retval.append(canonicalize_lang(cv))
+            except:
+                pass
+        return ', '.join(retval)
+
 _formatter_builtins = [
     BuiltinAdd(), BuiltinAnd(), BuiltinAssign(), BuiltinBooksize(),
     BuiltinCapitalize(), BuiltinCmp(), BuiltinContains(), BuiltinCount(),
@@ -1005,7 +1044,8 @@ _formatter_builtins = [
     BuiltinFirstNonEmpty(), BuiltinField(), BuiltinFormatDate(),
     BuiltinFormatNumber(), BuiltinFormatsModtimes(), BuiltinFormatsSizes(),
     BuiltinHasCover(), BuiltinHumanReadable(), BuiltinIdentifierInList(),
-    BuiltinIfempty(), BuiltinInList(), BuiltinListDifference(),
+    BuiltinIfempty(), BuiltinLanguageCodes(), BuiltinLanguageStrings(),
+    BuiltinInList(), BuiltinListDifference(),
     BuiltinListIntersection(), BuiltinListitem(), BuiltinListSort(),
     BuiltinListUnion(), BuiltinLookup(),
     BuiltinLowercase(), BuiltinMultiply(), BuiltinNot(),