Template language: Add a current_library_name() function that can be used to return the name of the currently opened library in calibre

src/calibre/manual/template_lang.rst

@@ -242,6 +242,7 @@ The following functions are available in addition to those described in single-f
     * ``assign(id, val)`` -- assigns val to id, then returns val. id must be an identifier, not an expression
     * ``booksize()`` -- returns the value of the |app| 'size' field. Returns '' if there are no formats.
     * ``cmp(x, y, lt, eq, gt)`` -- compares x and y after converting both to numbers. Returns ``lt`` if x < y. Returns ``eq`` if x == y. Otherwise returns ``gt``.
+    * ``current_library_name() -- `` return the last name on the path to the current calibre library. This function can be called in template program mode using the template ``{:'current_library_name()'}``.
     * ``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 either ``date1`` or ``date2`` are not dates, the function returns the empty string.
     * ``divide(x, y)`` -- returns x / y. Throws an exception if either x or y are not numbers.
     * ``field(name)`` -- returns the metadata field named by ``name``.

src/calibre/utils/formatter_functions.py

@@ -1106,9 +1106,22 @@ class BuiltinLanguageCodes(BuiltinFormatterFunction):
                 pass
         return ', '.join(retval)
 
+class BuiltinCurrentLibraryName(BuiltinFormatterFunction):
+    name = 'current_library_name'
+    arg_count = 0
+    category = 'Get values from metadata'
+    __doc__ = doc = _('current_library_name() -- '
+            'return the last name on the path to the current calibre library. '
+            'This function can be called in template program mode using the '
+            'template "{:\'current_library_name()\'}".')
+    def evaluate(self, formatter, kwargs, mi, locals):
+        from calibre.library import current_library_name
+        return current_library_name()
+
 _formatter_builtins = [
     BuiltinAdd(), BuiltinAnd(), BuiltinAssign(), BuiltinBooksize(),
     BuiltinCapitalize(), BuiltinCmp(), BuiltinContains(), BuiltinCount(),
+    BuiltinCurrentLibraryName(),
     BuiltinDaysBetween(), BuiltinDivide(), BuiltinEval(),
     BuiltinFirstNonEmpty(), BuiltinField(), BuiltinFormatDate(),
     BuiltinFormatNumber(), BuiltinFormatsModtimes(), BuiltinFormatsSizes(),