Doctor

Doctor is a self-contained directory management library for Node.js. This libary is based on the Simple Resource Protocol philosophy: one object to manage a single resource (or directory in this case). While it attempts to be "simple" (and is to some degree), this library can cause filesystem management to get complex, very fast. Proper usage can and will prevent this.

Doctor uses heavy caching to maintain filesystem appearances. That being said, this library is reccomended for situations that need high usability (ie you need most fs commands) on a single directory with a small amount of sub-items (< 5000?).

Install

npm install directory-doctor --save

The --save will tell npm to add it to your package.json.

Usage

To use Doctor, create a new object from the base class. The first argument is the path to the folder you want to use. If the folder doesn't exist, it is created. The second argument should be an options object. Doctor extends event emitter and before it can be used, you will need to wait for the "ready" event.

var Doctor = require('directory-doctor'),
	d = new Doctor('my-folder');

d.on("ready", function() {
	// Do stuff here
});

d.on("error", function() {
	// Catch any async errors that might pop up
})

Examples

Doctor maintains an internal cache of write streams to allow for semi-synchronous writes. In the example below, Doctor will create two writestreams for the two new files. If the folder other doesn't exist, this will error (pass a callback to prevent this). To "flush" the cache and send EOF to all the streams, the async function save is called.

d.set("other/one.txt", "Hullo!");
d.set("other/two.txt", "Two Hellos!");

d.save(function(err) {
	if (err) console.log(err.stack);
	else console.log("Done!");
});

Doctor is great for multiple files/directories as well. An object or array for the second arugment will cue Doctor to create a directory instead of a file. Filling the object with strings or buffers will fill the folder with those files. Passing a callback for the third argument tells Doctor to ignore the write cache and close the streams immediately.

d.set("/", {
	"other": {
		"one.txt": "One.",
		"two.txt": "Two."
	},
	"a.txt": "Something for a...",
	"b.txt": "And then somethig for B!"
}, function(err) {
	if (err) console.log(err.stack);
	else d.get("other/one.txt", function(err, data) {
		if (err) console.log(err.stack);
		else console.log(data.toString());
	});
});

Doctor will return the writestream if you don't pass a callback. This can cause some weird filesystem write orders to happen. In the example below, one.txt would end up containing "Overwr Oh hai again." This is because the call to one.write() happens after the second call to d.set().

var one = d.set("other/one.txt", "Hullo!");
one.write(" Oh hai again.");
one.end();

d.set("other/one.txt", "Overwritten!");

Doctor also has synchronous versions of most of the major methods. Most are truly synchronous, except for Doctor.replaceSync which calls Doctor.set() internally (instead of Doctor.setSync()). Due to this, a Doctor.save() must be called after this function is run to flush the write cache.

d.replaceSync([ "other/one.txt", "a.txt" ], function(file, stat) {
	return JSON.stringify(stat, null, "\t");
});

d.save(function(err) {
	if (err) console.log(err.stack);
	else console.log("Done!");
});

Sometimes the internal tree gets a little out of balance. Call Doctor.refresh() to re-walk the directory tree and refresh the cache. This generally shouldn't happen unless using Doctor.set() without a callback and Doctor.save() hasn't been called yet. Doctor watches the tree for changes, so even outside changes will be caught.

d.refresh(function(err) {
	if (err) console.log(err.stack);
	else console.log("Refreshed!");
});

Doctor has a handleful of other useful methods as well.

// Watch all the files in the "other" folder, deeply.
d.watch("other/**", function(file, stat) {
	console.log(file + " changed...");
});

// Copy the folder "src" in the CWD (ie where ever the script is being run) to the `Doctor` directory.
d.load("src", function(err) {
	if (err) console.log(err.stack);
	else console.log("Done!");
});

// Move the file "a.txt" in the `Doctor` directory to "../a-old.txt". The base directory for the second argument is the `Doctor` directory.
d.move("a.txt", "../a-old.txt", function(err) {
	if (err) console.log(err.stack);
	else console.log("Done!");
});