# 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 a `repo.json` file. The `repo.json` file provides additional information such as the name of the plugin, the plugin's website, dependencies, etc... [Here is an example `repo.json` file](https://github.com/micro-editor/updated-plugins/blob/master/go-plugin/repo.json) from the go plugin, which has the following file structure: ``` ~/.config/micro/plug/go-plugin/ go.lua repo.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 `repo.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. ## 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. This function is called after buffers have been initialized. * `preinit()`: initialization function called before buffers have been initialized. * `postinit()`: initialization function called after `init()`. * `onSetActive(bufpane)`: runs when changing the currently active panel. * `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. * `onRune(bufpane, rune)`: runs when the composed rune has been inserted * `preRune(bufpane, rune)`: runs before the composed rune will be inserted 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. 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{}...)`: temporarily close micro and print a message - `TermError(filename string, lineNum int, err string)`: temporarily close micro and print an error formatted as `filename, lineNum: err`. - `InfoBar()`: return the infobar BufPane object. - `Log(msg interface{}...)`: write a message to `log.txt` (requires `-debug` flag, or binary built with `build-dbg`). - `SetStatusInfoFn(fn string)`: register the given lua function as accessible from the statusline formatting options. - `CurPane() *BufPane`: returns the current BufPane, or nil if the current pane is not a BufPane. - `CurTab() *Tab`: returns the current tab. - `After(t time.Duration, f func())`: run function `f` in the background after time `t` elapses. See https://pkg.go.dev/time#Duration for the usage of `time.Duration`. * `micro/config` - `MakeCommand(name string, action func(bp *BufPane, args[]string), completer buffer.Completer)`: create a command with the given name, and lua callback function when the command is run. A completer may also be given to specify how autocompletion should work with the custom command. - `FileComplete`: autocomplete using files in the current directory - `HelpComplete`: autocomplete using names of help documents - `OptionComplete`: autocomplete using names of options - `OptionValueComplete`: autocomplete using names of options, and valid values afterwards - `NoComplete`: no autocompletion suggestions - `TryBindKey(k, v string, overwrite bool) (bool, error)`: bind the key `k` to the string `v` in the `bindings.json` file. If `overwrite` is true, this will overwrite any existing binding to key `k`. Returns true if the binding was made, and a possible error (for example writing to `bindings.json` can cause an error). - `Reload()`: reload configuration files. - `AddRuntimeFileFromMemory(filetype RTFiletype, filename, data string)`: add a runtime file to the `filetype` runtime filetype, with name `filename` and data `data`. - `AddRuntimeFilesFromDirectory(plugin string, filetype RTFiletype, directory, pattern string)`: add runtime files for the given plugin with the given RTFiletype from a directory within the plugin root. Only adds files that match the pattern using Go's `filepath.Match` - `AddRuntimeFile(plugin string, filetype RTFiletype, filepath string)`: add a given file inside the plugin root directory as a runtime file to the given RTFiletype category. - `ListRuntimeFiles(fileType RTFiletype) []string`: returns a list of names of runtime files of the given type. - `ReadRuntimeFile(fileType RTFiletype, name string) string`: returns the contents of a given runtime file. - `NewRTFiletype() int`: creates a new RTFiletype, and returns its value. - `RTColorscheme`: runtime files for colorschemes. - `RTSyntax`: runtime files for syntax files. - `RTHelp`: runtime files for help documents. - `RTPlugin`: runtime files for plugin source code. - `RegisterCommonOption(pl string, name string, defaultvalue interface{})`: registers a new option with for the given plugin. The name of the option will be `pl.name`, and will have the given default value. Since this registers a common option, the option will be modifiable on a per-buffer basis, while also having a global value (in the GlobalSettings map). - `RegisterGlobalOption(pl string, name string, defaultvalue interface{})`: same as `RegisterCommonOption` but the option cannot be modified locally to each buffer. - `GetGlobalOption(name string) interface{}`: returns the value of a given plugin in the `GlobalSettings` map. - `SetGlobalOption(option, value string) error`: sets an option to a given value. Same as using the `> set` command. This will parse the value to the actual value type. - `SetGlobalOptionNative(option string, value interface{}) error`: sets an option to a given value, where the type of value is the actual type of the value internally. * `micro/shell` - `ExecCommand(name string, arg ...string) (string, error)`: runs an executable with the given arguments, and pipes the output (stderr and stdout) of the executable to an internal buffer, which is returned as a string, along with a possible error. - `RunCommand(input string) (string, error)`: same as `ExecCommand`, except this uses micro's argument parser to parse the arguments from the input. For example `cat 'hello world.txt' file.txt`, will pass two arguments in the `ExecCommand` argument list (quoting arguments will preserve spaces). - `RunBackgroundShell(input string) (func() string, error)`: returns a function that will run the given shell command and return its output. - `RunInteractiveShell(input string, wait bool, getOutput bool) (string, error)`: temporarily closes micro and runs the given command in the terminal. If `wait` is true, micro will wait for the user to press enter before returning to text editing. If `getOutput` is true, micro redirect stdout from the command to the returned string. - `JobStart(cmd string, onStdout, onStderr, onExit func(string, []interface{}), userargs ...interface{}) *exec.Cmd`: Starts a background job by running the shell on the given command (using `sh -c`). Three callbacks can be provided which will be called when the command generates stdout, stderr, or exits. The userargs will be passed to the callbacks, along with the output as the first argument of the callback. - `JobSpawn(cmd string, cmdArgs []string, onStdout, onStderr, onExit func(string, []interface{}), userargs ...interface{}) *exec.Cmd`: same as `JobStart`, except doesn't run the command through the shell and instead takes as inputs the list of arguments. - `JobStop(cmd *exec.Cmd)`: kills a job. - `JobSend(cmd *exec.Cmd, data string)`: sends some data to a job's stdin. - `RunTermEmulator(h *BufPane, input string, wait bool, getOutput bool, callback func(out string, userargs []interface{}), userargs []interface{}) error`: starts a terminal emulator from a given BufPane with the input command. If `wait` is true it will wait for the user to exit by pressing enter once the executable has terminated and if `getOutput` is true it will redirect the stdout of the process to a pipe which will be passed to the callback which is a function that takes a string and a list of optional user arguments. This function returns an error on systems where the terminal emulator is not supported. - `TermEmuSupported`: true on systems where the terminal emulator is supported and false otherwise. Supported systems: * Linux * MacOS * Dragonfly * OpenBSD * FreeBSD * `micro/buffer` - `NewMessage(owner string, msg string, start, end, Loc, kind MsgType) *Message`: creates a new message with an owner over a range given by the start and end locations. - `NewMessageAtLine(owner string, msg string, line int, kindMsgType) *Message`: creates a new message with owner, type and message at a given line. - `MTInfo`: info message. - `MTWarning`: warning message. - `MTError` error message. - `Loc(x, y int) Loc`: creates a new location struct. - `SLoc(line, row int) display.SLoc`: creates a new scrolling location struct. - `BTDefault`: default buffer type. - `BTLog`: log buffer type. - `BTRaw`: raw buffer type. - `BTInfo`: info buffer type. - `NewBuffer(text, path string) *Buffer`: creates a new buffer with the given text at a certain path. - `NewBufferFromFile(path string) (*Buffer, error)`: creates a new buffer by reading from disk at the given path. - `ByteOffset(pos Loc, buf *Buffer) int`: returns the byte index of the given position in a buffer. - `Log(s string)`: writes a string to the log buffer. - `LogBuf() *Buffer`: returns the log buffer. * `micro/util` - `RuneAt(str string, idx int) string`: returns the utf8 rune at a given index within a string. - `GetLeadingWhitespace(s string) string`: returns the leading whitespace of a string. - `IsWordChar(s string) bool`: returns true if the first rune in a string is a word character. - `String(b []byte) string`: converts a byte array to a string. - `RuneStr(r rune) string`: converts a rune to a string. - `Unzip(src, dest string) error`: unzips a file to given folder. - `HttpRequest(method string, url string, headers []string) (http.Response, error)`: makes a http request. 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://pkg.go.dev/github.com/zyedidia/micro/v2/internal 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 unicode/utf8 archive/zip net/http ``` 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. The following functions are also available from the go-humanize package: The `humanize` package exposes: * `Bytes` * `Ordinal` ## 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 (notably indentation) 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). * `diff`: integrates the `diffgutter` option with Git. If you are in a Git directory, the diff gutter will show changes with respect to the most recent Git commit rather than the diff since opening the file. 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 `commands` 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.