node.script
Description
Control a local Node.js process from Max. Messages preceded by script control the lifecycle of the Node script (start to start, stop to stop). Other messages will be sent to the process directly.
Discussion
Node is a JavaScript framework for writing applications. To learn more about Node, visit their website.
Some Max patchers will want to do things that are difficult to do from Max. For example, it might be desirable to pull some data from a web address, then parse and analyze that data to generate synthesis parameters. Or, one might want to watch a local folder for files, triggering some action inside Max when the contents of that folder change. For these kinds of long-running tasks, which may require some kind of complex, persistent state, Node can be a very useful tool.
Another reason to use Node is to take advantage of the wealth of open source modules registered with the Node Package Manager (NPM). These packages contain libraries of JavaScript code for doing everything from parsing dates, to training neural nets, to running a web server, to writing chord progressions and much more. Node for Max helps make these resources available to Max programmers.
To communicate with Max, the Node script uses the "max-api" Node module. This set of functions simplifies the process of sending data between the Node application and Max. This API can attach handlers to Max messages; parse Max dictionaries into JSON objects; and read, update and set named dictionaries within Max. For examples on how to use this API, see the code examples included with the Node for Max package, as well as the API documentation at https://docs.cycling74.com/maxnode.docs/max-node-api/
The node.script object refers to a JavaScript source file, so it has some overlap with the js object. However, there are some important differences. Unlike js, node.script runs in a separate process. This has some benefits when it comes to parallelization, since Max and the Node script can run on separate cores. The Node script is a full application, which means that once it's started it has its own run loop, and has total freedom with respect to what code it can run when. It responds to events just like any other application, and can even have its own Graphical User Interface (GUI). Messages sent to the Node script will be executed asynchronously, since Node and Max are running in separate processes. Finally, scripts running with node.script have access to the full Node library for network communication, file I/O and more.
Arguments
script [symbol]
Entry point for your Node application. Send node.script the start message to start running this script.
Attributes
args [16 atoms]
Arguments to be passed to the Node script on launch. Note that this attribute is only meaningful in conjunction with the autostart attribute. Otherwise, node.script will use the arguments supplied with the start message.
autostart [int]
Start the Node script automatically, without script start
defer [int]
When false (the default), messages from Node will be processed on the scheduler thread, at the same priority as other Max messages. Activating defer will move processing to the back of the low priority queue, same as the defer attribute on metro
log_path [symbol]
Debug only: specify a path to which a debug log will be written, for example ~/Documents/debug.txt
node_bin_path [symbol]
Override the built in Node executable. Optional. Only use this attribute if you'd like to use a different Node executable from the one included with Max for Node (possibly you want to use an older version for compatibility reasons).
npm_bin_path [symbol]
Override the built in NPM executable. Optional. Only use this attribute if you'd like to use a different NPM executable from the one included with Max for Node (possibly you want to use an older version for compatibility reasons).
pm_path [symbol]
Debug only: specify the path to the process manager script
restart [int] (default: 1)
When restart is enabled (default) node.script will restart automatically after a node code crash inside a handler callback. If restart is disabled, automatic restarts are suppressed.
running [int]
Read only: 1 if there is a running Node process, 0 otherwise
watch [int]
True if node.script should relaunch the Node script automatically when the source file changes
Common Box Attributes
annotation [symbol]
Sets the text that will be displayed in the Clue window when the user moves the mouse over the object.
background [int] (default: 0)
Adds or removes the object from the patcher's background layer. background 1 adds the object to the background layer, background 0 removes it. Objects in the background layer are shown behind all objects in the default foreground layer.
color [4 floats]
Sets the color for the object box outline.
fontface [int]
Sets the type style used by the object. The options are:
plain
bold
italic
bold italic
Possible values:
0 = 'regular'
1 = 'bold'
2 = 'italic'
3 = 'bold italic'
fontname [symbol]
Sets the object's font.
fontsize [float]
Sets the object's font size (in points).
Possible values:
'8'
'9'
'10'
'11'
'12'
'13'
'14'
'16'
'18'
'20'
'24'
'30'
'36'
'48'
'64'
'72'
hidden [int] (default: 0)
Toggles whether an object is hidden when the patcher is locked.
hint [symbol]
Sets the text that will be displayed in as a pop-up hint when the user moves the mouse over the object in a locked patcher.
ignoreclick [int] (default: 0)
Toggles whether an object ignores mouse clicks in a locked patcher.
jspainterfile [symbol]
JS Painter File
patching_rect [4 floats] (default: 0. 0. 100. 0.)
Sets the position and size of the object in the patcher window.
position [2 floats]
Sets the object's x and y position in both patching and presentation modes (if the object belongs to its patcher's presentation), leaving its size unchanged.
presentation [int] (default: 0)
Sets whether an object belongs to the patcher's presentation.
presentation_rect [4 floats] (default: 0. 0. 0. 0.)
Sets the x and y position and width and height of the object in the patcher's presentation, leaving its patching position unchanged.
rect [4 floats]
Sets the x and y position and width and height of the object in both patching and presentation modes (if the object belongs to its patcher's presentation).
size [2 floats]
Sets the object's width and height in both patching and presentation modes (if the object belongs to its patcher's presentation), leaving its position unchanged.
textcolor [4 floats]
Sets the color for the object's text in RGBA format.
textjustification [int]
Sets the justification for the object's text.
Possible values:
0 = 'left'
1 = 'center'
2 = 'right'
varname [symbol]
Sets the patcher's scripting name, which can be used to address the object by name in pattr, scripting messages to thispatcher, and the js object.
Messages
bang
anything
Arguments
api
(mouse)
reveal
script
Arguments
Messages beginning with the symbol script are used to start, stop and query the Node process. The symbol following script determines how the message will be handled. Subsequent arguments are passed to that handler, if applicable.
npm - Interface with the Node Package Manager (npm). If the node script is in a node package, then this message can be used to (for example) install module dependencies listed in package.json into node_modules. The npm message assumes that package.json is in the same folder as the script specified as the first argument to node.script. Symbols following npm will be sent as arguments to npm (for example script npm install will run `npm install`).
processStatus - Get a dictionary describing the status of the running Node process (if any)
reboot - Rarely used. Reboot the Node process manager if it has crashed.
running - Returns 1 if there is a running node process, and 0 otherwise
status - Returns a dictionary with information about the installed version of Node
start - Start running the Node script with the given (optional) arguments. Arguments following start will be available as command line arguments to the Node script.
stop - Stop running the Node script