时间:2021-07-01 10:21:17 帮助过:4人阅读
在开始编写插件之前,你需要确认 Vim 支持 Python,通过以下命令来判别:
接下来我们通过一个简单的例子来学习用 Python 编写 Vim 插件,该插件用来获取 Reddit 首页信息并显示在当前缓冲区上。
首先在 Vim 新建 vimmit.vim 文件,我们首先需要判断是否支持 Python,如果不支持给出提示信息:
if !has('python') echo "Error: Required vim compiled with +python" finish endif
上面这段代码就是用 VimL 编写的,它将检查 Vim 是否支持 Python。
下面是用 Python 编写的 Reddit() 主函数:
" Vim comments start with a double quote. " Function definition is VimL. We can mix VimL and Python in " function definition. function! Reddit() " We start the python code like the next line. python << EOF # the vim module contains everything we need to interface with vim from # python. We need urllib2 for the web service consumer. import vim, urllib2 # we need json for parsing the response import json # we define a timeout that we'll use in the API call. We don't want # users to wait much. TIMEOUT = 20 URL = "http://reddit.com/.json" try: # Get the posts and parse the json response response = urllib2.urlopen(URL, None, TIMEOUT).read() json_response = json.loads(response) posts = json_response.get("data", "").get("children", "") # vim.current.buffer is the current buffer. It's list-like object. # each line is an item in the list. We can loop through them delete # them, alter them etc. # Here we delete all lines in the current buffer del vim.current.buffer[:] # Here we append some lines above. Aesthetics. vim.current.buffer[0] = 80*"-" for post in posts: # In the next few lines, we get the post details post_data = post.get("data", {}) up = post_data.get("ups", 0) down = post_data.get("downs", 0) title = post_data.get("title", "NO TITLE").encode("utf-8") score = post_data.get("score", 0) permalink = post_data.get("permalink").encode("utf-8") url = post_data.get("url").encode("utf-8") comments = post_data.get("num_comments") # And here we append line by line to the buffer. # First the upvotes vim.current.buffer.append("↑ %s"%up) # Then the title and the url vim.current.buffer.append(" %s [%s]"%(title, url,)) # Then the downvotes and number of comments vim.current.buffer.append("↓ %s | comments: %s [%s]"%(down, comments, permalink,)) # And last we append some "-" for visual appeal. vim.current.buffer.append(80*"-") except Exception, e: print e EOF " Here the python code is closed. We can continue writing VimL or python again. endfunction
使用如下命令保存文件
然后调用该插件:
这个命令用起来不那么方便,因此我们再定义一个命令:
我们定义了命令:Reddit来调用这个函数。-nargs 参数声明命令行中有多少个参数。
关于函数参数的问题:
问:如何访问函数中的参数?
function! SomeName(arg1, arg2, arg3) " Get the first argument by name in VimL let firstarg=a:arg1 " Get the second argument by position in Viml let secondarg=a:1 " Get the arguments in python python << EOF import vim first_argument = vim.eval("a:arg1") #or vim.eval("a:0") second_argument = vim.eval("a:arg2") #or vim.eval("a:1")
你可以使用 ... 来处理可变个数参数来替换特定的参数名,可通过位置或者命名参数来访问,如:(arg1, arg2, ...)
问:如何在 Python 中调用 Vim 命令?
问:如何定义全局变量,并在 VimL 和 Python 中访问?
全局变量使用形如 g:. 的前缀,定义全局变量前应该检查该变量是否已定义:
if !exists("g:reddit_apicall_timeout") let g:reddit_apicall_timeout=40 endif
然后你通过下面代码在 Python 中访问这个变量:
TIMEOUT = vim.eval("g:reddit_apicall_timeout")
可通过下面的方法来对全局变量进行重新赋值:
let g:reddit_apicall_timeout=60
更多关于使用 Python 编写 Vim 插件的说明请看官方文档。
备注:
一旦你用过VimL,就会发现它挺简单的,你用python写的代码也可以用它来实现。详细请参考vim python模块文档,这是一份重要的参考资料。
除了上述文档,你也可以在IBM developerWorks网站找到一些有用的资料。