nvim插件管理工具packer的使用

packer 🔗是一个功能强大且支持扩展的neovim插件管理工具，只要是基于neovim实现的ide全部是用packer来管理插件的，因此packer是学习nvim的必学插件。

packer自动安装

packer是管理插件的插件，一般在init.vim或者init.lua中写入自动安装脚本，让nvim启动后就执行packer的安装，如：

local fn = vim.fn
local install_path = fn.stdpath "data" .. "/site/pack/packer/start/packer.nvim"
if fn.empty(fn.glob(install_path)) > 0 then
  PACKER_BOOTSTRAP = fn.system {
    "git",
    "clone",
    "--depth",
    "1",
    "https://github.com/wbthomason/packer.nvim",
    install_path,
  }
  vim.cmd [[packadd packer.nvim]]
end

其中fn.stdpath "data"返回nvim放置程序数据的目录，mac上是~/.local/share/nvim，拼接/site/pack/packer/start/packer.nvim后就是packer的安装目录，fn.empty(fn.glob(install_path))用于判断packer是否已经安装，如果没有安装则拉取wbthomason/packer.nvim后执行vim的packadd命令添加它，只有通过packadd命令添加过vim才会加载。

指定插件配置文件保存后自动安装

vim写法

augroup packer_user_config
  autocmd!
  autocmd BufWritePost plugins.lua source <afile> | PackerCompile
augroup end

lua写法

vim.cmd([[
  augroup packer_user_config
    autocmd!
    autocmd BufWritePost plugins.lua source <afile> | PackerCompile
  augroup end
]])

其中plugins.lua即为插件配置文件，实际触发文件写入成功（BufWritePost）后执行的是PackerCompile命令，autocmd为自动执行，后面加!表示删除该组下的自动命令。

引入packer

安装成功后我们执行载入并在之后使用packer：

local status_ok, packer = pcall(require, "packer")
if not status_ok then
  return
end

使用init方法修改默认配置

下面为官网的配置及注释说明，如display为弹框样式，log为日志等级，还有autoremove、max_jobs等配置项：

packer.init {
  ensure_dependencies   = true, -- Should packer install plugin dependencies?
  snapshot = nil, -- Name of the snapshot you would like to load at startup
  snapshot_path = join_paths(stdpath 'cache', 'packer.nvim'), -- Default save directory for snapshots
  package_root   = util.join_paths(vim.fn.stdpath('data'), 'site', 'pack'),
  compile_path = util.join_paths(vim.fn.stdpath('config'), 'plugin', 'packer_compiled.lua'),
  plugin_package = 'packer', -- The default package for plugins
  max_jobs = nil, -- Limit the number of simultaneous jobs. nil means no limit
  auto_clean = true, -- During sync(), remove unused plugins
  compile_on_sync = true, -- During sync(), run packer.compile()
  disable_commands = false, -- Disable creating commands
  opt_default = false, -- Default to using opt (as opposed to start) plugins
  transitive_opt = true, -- Make dependencies of opt plugins also opt by default
  transitive_disable = true, -- Automatically disable dependencies of disabled plugins
  auto_reload_compiled = true, -- Automatically reload the compiled file after creating it.
  git = {
    cmd = 'git', -- The base command for git operations
    subcommands = { -- Format strings for git subcommands
      update         = 'pull --ff-only --progress --rebase=false',
      install        = 'clone --depth %i --no-single-branch --progress',
      fetch          = 'fetch --depth 999999 --progress',
      checkout       = 'checkout %s --',
      update_branch  = 'merge --ff-only @{u}',
      current_branch = 'branch --show-current',
      diff           = 'log --color=never --pretty=format:FMT --no-show-signature HEAD@{1}...HEAD',
      diff_fmt       = '%%h %%s (%%cr)',
      get_rev        = 'rev-parse --short HEAD',
      get_msg        = 'log --color=never --pretty=format:FMT --no-show-signature HEAD -n 1',
      submodules     = 'submodule update --init --recursive --progress'
    },
    depth = 1, -- Git clone depth
    clone_timeout = 60, -- Timeout, in seconds, for git clones
    default_url_format = 'https://github.com/%s' -- Lua format string used for "aaa/bbb" style plugins
  },
  display = {
    non_interactive = false, -- If true, disable display windows for all operations
    open_fn  = nil, -- An optional function to open a window for packer's display
    open_cmd = '65vnew \\[packer\\]', -- An optional command to open a window for packer's display
    working_sym = '⟳', -- The symbol for a plugin being installed/updated
    error_sym = '✗', -- The symbol for a plugin with an error in installation/updating
    done_sym = '✓', -- The symbol for a plugin which has completed installation/updating
    removed_sym = '-', -- The symbol for an unused plugin which was removed
    moved_sym = '→', -- The symbol for a plugin which was moved (e.g. from opt to start)
    header_sym = '━', -- The symbol for the header line in packer's display
    show_all_info = true, -- Should packer show all update details automatically?
    prompt_border = 'double', -- Border style of prompt popups.
    keybindings = { -- Keybindings for the display window
      quit = 'q',
      toggle_info = '<CR>',
      diff = 'd',
      prompt_revert = 'r',
    }
  },
  luarocks = {
    python_cmd = 'python' -- Set the python command to use for running hererocks
  },
  log = { level = 'warn' }, -- The default print log level. One of: "trace", "debug", "info", "warn", "error", "fatal".
  profile = {
    enable = false,
    threshold = 1, -- integer in milliseconds, plugins which load faster than this won't be shown in profile output
  },
  autoremove = false, -- Remove disabled or unused plugins without prompting the user
}

使用startup安装插件

return packer.startup(function(use)
  use "wbthomason/packer.nvim" -- 管理packer自己，如更新
  use { "nvim-lua/plenary.nvim", as = 'plenary' } -- 常用工具插件

  -- 如果第一次安装还需要执行下sync命令：require("packer").sync()
end)

startup方法有三种使用方式，上面的是最常用的一种，可传入配置项控制插件行为，如配置run参数在安装插件成功后执行命令，参数包括：

use {
  'myusername/example',        -- The plugin location string
  -- The following keys are all optional
  disable = boolean,           -- Mark a plugin as inactive
  as = string,                 -- Specifies an alias under which to install the plugin
  installer = function,        -- Specifies custom installer. See "custom installers" below.
  updater = function,          -- Specifies custom updater. See "custom installers" below.
  after = string or list,      -- Specifies plugins to load before this plugin. See "sequencing" below
  rtp = string,                -- Specifies a subdirectory of the plugin to add to runtimepath.
  opt = boolean,               -- Manually marks a plugin as optional.
  branch = string,             -- Specifies a git branch to use
  tag = string,                -- Specifies a git tag to use. Supports '*' for "latest tag"
  commit = string,             -- Specifies a git commit to use
  lock = boolean,              -- Skip updating this plugin in updates/syncs. Still cleans.
  run = string, function, or table, -- Post-update/install hook. See "update/install hooks".
  requires = string or list,   -- Specifies plugin dependencies. See "dependencies".
  rocks = string or list,      -- Specifies Luarocks dependencies for the plugin
  config = string or function, -- Specifies code to run after this plugin is loaded.
  -- The setup key implies opt = true
  setup = string or function,  -- Specifies code to run before this plugin is loaded.
  -- The following keys all imply lazy-loading and imply opt = true
  cmd = string or list,        -- Specifies commands which load this plugin. Can be an autocmd pattern.
  ft = string or list,         -- Specifies filetypes which load this plugin.
  keys = string or list,       -- Specifies maps which load this plugin. See "Keybindings".
  event = string or list,      -- Specifies autocommand events which load this plugin.
  fn = string or list          -- Specifies functions which load this plugin.
  cond = string, function, or list of strings/functions,   -- Specifies a conditional test to load this plugin
  module = string or list      -- Specifies Lua module names for require. When requiring a string which starts
                               -- with one of these module names, the plugin will be loaded.
  module_pattern = string/list -- Specifies Lua pattern of Lua module names for require. When
  requiring a string which matches one of these patterns, the plugin will be loaded.
}

常用vim命令

-- 执行编译load文件
:PackerCompile

-- 删除未使用或未开启的插件
:PackerClean

-- 先清理再安装插件
:PackerInstall

-- 先清理再更新插件
:PackerUpdate

-- 先执行更新再执行编译
:PackerSync

-- 立即加载插件
:PackerLoad completion-nvim ale