# Plugins Micro supports creating plugins with a simple Lua system. Plugins are folders containing Lua files and possibly other source files placed in `~/.config/micro/plug`. The plugin directory (within `plug`) should contain at least one Lua file and an `info.json` file. The info file provides additional information such as the name of the plugin, the plugin's website, dependencies, etc... Here is an example info file from the go plugin, which has the following file structure: ``` ~/.config/micro/plug/go-plugin/ go.lua info.json help/ go-plugin.md ``` The `go.lua` file contains the main code for the plugin, though the code may be distributed across multiple Lua files. The `info.json` file contains information about the plugin such as the website, description, version, and any requirements. Plugins may also have additional files which can be added to micro's runtime files, of which there are 5 types: * Colorschemes * Syntax files * Help files * Plugin files * Syntax header files In most cases, a plugin will want to add help files, but in certain cases a plugin may also want to add colorschemes or syntax files. It is unlikely for a plugin to need to add plugin files at runtime or syntax header files. No directory structure is enforced but keeping runtime files in their own directories is good practice. # Info file The `info.json` for the Go plugin is the following: ``` { "name": "go", "description": "Go formatting and tool support", "website": "https://github.com/micro-editor/go-plugin", "install": "https://github.com/micro-editor/go-plugin", "version": "1.0.0", "require": [ "micro >= 2.0.0" ] } ``` All fields are simply interpreted as strings, so the version does not need to be a semantic version, and the dependencies are also only meant to be parsed by humans. The name should be an identifier, and the website should point to a valid website. The install field should provide info about installing the plugin, or point to a website that provides information. Note that the name of the plugin is defined by the name field in the `info.json` and not by the installation path. Some functions micro exposes to plugins require passing the name of the plugin. ## Lua callbacks Plugins use Lua but also have access to many functions both from micro and from the Go standard library. Many callbacks are also defined which are called when certain events happen. Here is the list of callbacks which micro defines: * `init()`: this function should be used for your plugin initialization. * `onBufferOpen(buf)`: runs when a buffer is opened. The input contains the buffer object. * `onBufPaneOpen(bufpane)`: runs when a bufpane is opened. The input contains the bufpane object. * `onAction(bufpane)`: runs when `Action` is triggered by the user, where `Action` is a bindable action (see `> help keybindings`). A bufpane is passed as input and the function should return a boolean defining whether the view should be relocated after this action is performed. * `preAction(bufpane)`: runs immediately before `Action` is triggered by the user. Returns a boolean which defines whether the action should be canceled. For example a function which is run every time the user saves the buffer would be: ```lua function onSave(bp) ... return false end ``` The `bp` variable is a reference to the bufpane the action is being executed within. This is almost always the current bufpane. All available actions are listed in the keybindings section of the help. For callbacks to mouse actions, you are also given the event info: ```lua function onMousePress(view, event) local x, y = event:Position() return false end ``` These functions should also return a boolean specifying whether the bufpane should be relocated to the cursor or not after the action is complete. ## Accessing micro functions Some of micro's internal information is exposed in the form of packages which can be imported by Lua plugins. A package can be imported in Lua and a value within it can be accessed using the following syntax: ```lua local micro = import("micro") micro.Log("Hello") ``` The packages and functions are listed below (in Go type signatures): * `micro` - `TermMessage(msg interface{}...)` - `TermError()` - `InfoBar()` - `Log(msg interface{}...)` - `SetStatusInfoFn(fn string)` * `micro/config` - `MakeCommand` - `FileComplete` - `HelpComplete` - `OptionComplete` - `OptionValueComplete` - `NoComplete` - `TryBindKey` - `Reload` - `AddRuntimeFilesFromDirectory` - `AddRuntimeFileFromMemory` - `AddRuntimeFile` - `ListRuntimeFiles` - `ReadRuntimeFile` - `RTColorscheme` - `RTSyntax` - `RTHelp` - `RTPlugin` - `RegisterCommonOption` - `RegisterGlobalOption` * `micro/shell` - `ExecCommand` - `RunCommand` - `RunBackgroundShell` - `RunInteractiveShell` - `JobStart` - `JobSpawn` - `JobStop` - `JobStop` - `RunTermEmulator` - `TermEmuSupported` * `micro/buffer` - `NewMessage` - `NewMessageAtLine` - `MTInfo` - `MTWarning` - `MTError` - `Loc` - `BTDefault` - `BTLog` - `BTRaw` - `BTInfo` - `NewBufferFromFile` - `ByteOffset` - `Log` - `LogBuf` * `micro/util` - `RuneAt` - `GetLeadingWhitespace` - `IsWordChar` This may seem like a small list of available functions but some of the objects returned by the functions have many methods. The Lua plugin may access any public methods of an object returned by any of the functions above. Unfortunately it is not possible to list all the available functions on this page. Please go to the internal documentation at https://godoc.org/github.com/zyedidia/micro to see the full list of available methods. Note that only methods of types that are available to plugins via the functions above can be called from a plugin. For an even more detailed reference see the source code on Github. For example, with a BufPane object called `bp`, you could call the `Save` function in Lua with `bp:Save()`. Note that Lua uses the `:` syntax to call a function rather than Go's `.` syntax. ```go micro.InfoBar().Message() ``` turns to ```lua micro.InfoBar():Message() ``` ## Accessing the Go standard library It is possible for your lua code to access many of the functions in the Go standard library. Simply import the package you'd like and then you can use it. For example: ```lua local ioutil = import("io/ioutil") local fmt = import("fmt") local micro = import("micro") local data, err = ioutil.ReadFile("SomeFile.txt") if err ~= nil then micro.InfoBar():Error("Error reading file: SomeFile.txt") else -- Data is returned as an array of bytes -- Using Sprintf will convert it to a string local str = fmt.Sprintf("%s", data) -- Do something with the file you just read! -- ... end ``` Here are the packages from the Go standard library that you can access. Nearly all functions from these packages are supported. For an exact list of which functions are supported you can look through `lua.go` (which should be easy to understand). ``` fmt io io/ioutil net math math/rand os runtime path filepath strings regexp errors time ``` For documentation for each of these functions, see the Go standard library documentation at https://golang.org/pkg/ (for the packages exposed to micro plugins). The Lua standard library is also available to plugins though it is rather small. ## Adding help files, syntax files, or colorschemes in your plugin You can use the `AddRuntimeFile(name string, type config.RTFiletype, path string)` function to add various kinds of files to your plugin. For example, if you'd like to add a help topic to your plugin called `test`, you would create a `test.md` file, and call the function: ```lua config = import("micro/config") config.AddRuntimeFile("test", config.RTHelp, "test.md") ``` Use `AddRuntimeFilesFromDirectory(name, type, dir, pattern)` to add a number of files to the runtime. To read the content of a runtime file use `ReadRuntimeFile(fileType, name string)` or `ListRuntimeFiles(fileType string)` for all runtime files. In addition, there is `AddRuntimeFileFromMemory` which adds a runtime file based on a string that may have been constructed at runtime. ## Default plugins There are 6 default plugins that come pre-installed with micro. These are * `autoclose`: automatically closes brackets, quotes, etc... * `comment`: provides automatic commenting for a number of languages * `ftoptions`: alters some default options depending on the filetype * `linter`: provides extensible linting for many languages * `literate`: provides advanced syntax highlighting for the Literate programming tool. * `status`: provides some extensions to the status line (integration with Git and more). See `> help linter`, `> help comment`, and `> help status` for additional documentation specific to those plugins. These are good examples for many use-cases if you are looking to write your own plugins. ## Plugin Manager Micro also has a built in plugin manager which you can invoke with the `> plugin ...` command, or in the shell with `micro -plugin ...`. For the valid commands you can use, see the `command` help topic. The manager fetches plugins from the channels (which is simply a list of plugin metadata) which it knows about. By default, micro only knows about the official channel which is located at github.com/micro-editor/plugin-channel but you can add your own third-party channels using the `pluginchannels` option and you can directly link third-party plugins to allow installation through the plugin manager with the `pluginrepos` option. If you'd like to publish a plugin you've made as an official plugin, you should upload your plugin online (to Github preferably) and add a `repo.json` file. This file will contain the metadata for your plugin. Here is an example: ```json [{ "Name": "pluginname", "Description": "Here is a nice concise description of my plugin", "Website": "https://github.com/user/plugin" "Tags": ["python", "linting"], "Versions": [ { "Version": "1.0.0", "Url": "https://github.com/user/plugin/archive/v1.0.0.zip", "Require": { "micro": ">=1.0.3" } } ] }] ``` Then open a pull request at github.com/micro-editor/plugin-channel adding a link to the raw `repo.json` that is in your plugin repository. To make updating the plugin work, the first line of your plugins lua code should contain the version of the plugin. (Like this: `VERSION = "1.0.0"`) Please make sure to use [semver](http://semver.org/) for versioning.