Trying to improve jedi-vim, when Jedi is not found. Fixes #263.

autoload/jedi.vim

@@ -48,7 +48,7 @@ endfun
 " show_documentation
 " ------------------------------------------------------------------------
 function! jedi#show_documentation()
-    Python jedi_vim.show_documentation()
+    Python if jedi_vim.show_documentation() is None: vim.command('return')
 
     let bn = bufnr("__doc__")
     if bn > 0
@@ -150,10 +150,6 @@ function! jedi#do_popup_on_dot_in_highlight()
 endfunc
 
 
-function! jedi#popup_on_dot_string()
-endfunction
-
-
 function! jedi#configure_call_signatures()
     if g:jedi#show_call_signatures == 2  " Command line call signatures
         " Need to track changes to avoid multiple undo points for a single edit

initialize.py

@@ -18,8 +18,5 @@ import traceback
 
 # update the sys path to include the jedi_vim script
 sys.path.insert(0, vim.eval('expand(s:script_path)'))
-try:
+import jedi_vim
-    import jedi_vim
-except ImportError:
-    vim.command('echoerr "Please install Jedi if you want to use jedi_vim."')
 sys.path.pop(1)

jedi_vim.py

@@ -13,8 +13,29 @@ try:
 except ImportError:
     from itertools import izip_longest as zip_longest  # Python 2
 
+
+def no_jedi_warning():
+    vim.command('echoerr "Please install Jedi if you want to use jedi_vim."')
+
+
+def echo_highlight(msg):
+    vim_command('echohl WarningMsg | echom "%s" | echohl None' % msg)
+
+
 import vim
-import jedi
+try:
+    import jedi
+except ImportError:
+    no_jedi_warning()
+    jedi = None
+else:
+    version = jedi.__version__
+    if isinstance(version, str):
+        # the normal use case, now.
+        from jedi import utils
+        version = utils.version_info()
+    if version < (0, 7):
+        echo_highlight('Please update your Jedi version, it is to old.')
 
 is_py3 = sys.version_info[0] >= 3
 if is_py3:
@@ -31,6 +52,19 @@ def catch_and_print_exceptions(func):
     return wrapper
 
 
+def _check_jedi_availability(show_error=False):
+    def func_receiver(func):
+        def wrapper(*args, **kwargs):
+            if jedi is None:
+                if show_error:
+                    no_jedi_warning()
+                return
+            else:
+                return func(*args, **kwargs)
+        return wrapper
+    return func_receiver
+
+
 class VimError(Exception):
     def __init__(self, message, throwpoint, executing):
         super(type(self), self).__init__(message)
@@ -61,10 +95,6 @@ def vim_command(string):
     _catch_exception(string, 0)
 
 
-def echo_highlight(msg):
-    vim_command('echohl WarningMsg | echom "%s" | echohl None' % msg)
-
-
 class PythonToVimStr(unicode):
     """ Vim has a different string implementation of single quotes """
     __slots__ = []
@@ -101,6 +131,7 @@ def get_script(source=None, column=None):
     return jedi.Script(source, row, column, buf_path, encoding)
 
 
+@_check_jedi_availability(show_error=False)
 @catch_and_print_exceptions
 def completions():
     row, column = vim.current.window.cursor
@@ -156,6 +187,7 @@ def completions():
         vim.command('return ' + strout)
 
 
+@_check_jedi_availability(show_error=True)
 @catch_and_print_exceptions
 def goto(is_definition=False, is_related_name=False, no_output=False):
     definitions = []
@@ -208,6 +240,7 @@ def goto(is_definition=False, is_related_name=False, no_output=False):
     return definitions
 
 
+@_check_jedi_availability(show_error=True)
 @catch_and_print_exceptions
 def show_documentation():
     script = get_script()
@@ -230,6 +263,7 @@ def show_documentation():
         text = ('\n' + '-' * 79 + '\n').join(docs)
         vim.command('let l:doc = %s' % repr(PythonToVimStr(text)))
         vim.command('let l:doc_lines = %s' % len(text.split('\n')))
+    return True
 
 
 @catch_and_print_exceptions
@@ -257,6 +291,7 @@ def clear_call_signatures():
     vim.current.window.cursor = cursor
 
 
+@_check_jedi_availability(show_error=False)
 @catch_and_print_exceptions
 def show_call_signatures(signatures=()):
     if vim_eval("has('conceal') && g:jedi#show_call_signatures") == '0':
@@ -376,6 +411,7 @@ def cmdline_call_signatures(signatures):
                     % (spaces, signatures[0].call_name, text))
 
 
+@_check_jedi_availability(show_error=True)
 @catch_and_print_exceptions
 def rename():
     if not int(vim.eval('a:0')):
@@ -428,6 +464,7 @@ def rename():
             echo_highlight('Jedi did %s renames!' % len(temp_rename))
 
 
+@_check_jedi_availability(show_error=True)
 @catch_and_print_exceptions
 def py_import():
     # args are the same as for the :edit command
@@ -538,12 +575,3 @@ def escape_file_path(path):
 
 def print_to_stdout(level, str_out):
     print(str_out)
-
-
-version = jedi.__version__
-if isinstance(version, str):
-    # the normal use case, now.
-    from jedi import utils
-    version = utils.version_info()
-if version < (0, 7):
-    echo_highlight('Please update your Jedi version, it is to old.')