set 'formatexpr' automatically by g:clang_format#auto_formatexpr (fix #11)

Author: rhysd

README.md

@@ -1,4 +1,4 @@
-## Format your C++ code [![Build Status](https://travis-ci.org/rhysd/vim-clang-format.png?branch=master)](https://travis-ci.org/rhysd/vim-clang-format)
+## Format your C, C++ and Objective-C code [![Build Status](https://travis-ci.org/rhysd/vim-clang-format.png?branch=master)](https://travis-ci.org/rhysd/vim-clang-format)
 
 This plugin formats your C++ code with specific coding style using [clang](http://clang.llvm.org/).
 
@@ -84,6 +84,11 @@ Formatting is executed on `BufWritePre` event.
 When the value is 1, inserted lines are automatically formatted on leaving insert mode.
 Formatting is executed on `InsertLeave` event.
 
+- `g:clang_format#auto_formatexpr`
+
+When the value is 1, `formatexpr` option is set by vim-clang-format automatically in C, C++ and ObjC codes.
+Vim's format mappings (e.g. `gq`) get to use `clang-format` to format.
+
 ### Vimrc Example
 
 ```vim

autoload/clang_format.vim

@@ -119,6 +119,7 @@ let g:clang_format#style_options = s:getg('clang_format#style_options', {})
 let g:clang_format#detect_style_file = s:getg('clang_format#detect_style_file', 1)
 let g:clang_format#auto_format = s:getg('clang_format#auto_format', 0)
 let g:clang_format#auto_format_on_insert_leave = s:getg('clang_format#auto_format_on_insert_leave', 0)
+let g:clang_format#auto_formatexpr = s:getg('clang_format#auto_formatexpr', 0)
 " }}}
 
 " format codes {{{

doc/clang-format.txt

@@ -164,6 +164,14 @@ g:clang_format#auto_format_on_insert_leave
 
 
 
+g:clang_format#auto_formatexpr		        *g:clang_format#auto_formatexpr*
+
+    When the value is 1, 'formatexpr' option is set automatically in |c|, |cpp|
+    and |objc| codes.  Vim's format mappings (e.g. |gq|) get to use |clang-format|
+    to format.
+
+
+
 ==============================================================================
 SETUP EXAMPLE                                   *vim-clang-format-setup-example*
 

plugin/clang_format.vim

@@ -16,6 +16,7 @@ augroup plugin-clang-format-auto-format
     autocmd!
     autocmd BufWritePre * if &ft =~# '^\%(c\|cpp\|objc\)$' && g:clang_format#auto_format && clang_format#check_cmd() ==# '' | call clang_format#replace(1, line('$')) | endif
     autocmd FileType c,cpp,objc if g:clang_format#auto_format_on_insert_leave && clang_format#check_cmd() ==# '' | call clang_format#enable_format_on_insert() | endif
+    autocmd FileType c,cpp,objc if g:clang_format#auto_formatexpr && clang_format#check_cmd() ==# '' | setlocal formatexpr=clang_format#replace(v:lnum,v:lnum+v:count-1) | endif
 augroup END
 
 let g:loaded_clang_format = 1

t/clang_format_spec.vim

@@ -297,3 +297,25 @@ describe 'g:clang_format#auto_format_on_insert_leave'
 end
 
 " }}}
+
+" test for auto 'formatexpr' setting feature
+
+describe 'g:clang_format#auto_formatexpr'
+    before
+        let g:clang_format#auto_formatexpr = 1
+        new
+        execute 'silent' 'edit!' './'.s:root_dir.'t/test.cpp'
+    end
+
+    after
+        bdelete!
+    end
+
+    it 'formats the text object using gq operator'
+        doautocmd Filetype cpp
+        let expected = ClangFormat(1, line('$'))
+        normal ggVGgq
+        let actual = GetBuffer()
+        Expect expected ==# actual
+    end
+end