fs.readFileSync() and fs.readFile() static asset browserify transform
This module is a plugin for browserify to parse the AST
for fs.readFileSync() calls so that you can inline file contents into your
bundles.
Even though this module is intended for use with browserify, nothing about it is particularly specific to browserify so it should be generally useful in other projects.
for a main.js:
var fs = require('fs');
var html = fs.readFileSync(__dirname + '/robot.html', 'utf8');
console.log(html);and a robot.html:
<b>beep boop</b>first npm install brfs into your project, then:
$ browserify -t brfs example/main.js > bundle.js
now in the bundle output file,
var html = fs.readFileSync(__dirname + '/robot.html', 'utf8');turns into:
var html = "<b>beep boop</b>\n";var browserify = require('browserify');
var fs = require('fs');
var b = browserify('example/main.js');
b.transform('brfs');
b.bundle().pipe(fs.createWriteStream('bundle.js'));You can also use fs.readFile():
var fs = require('fs');
fs.readFile(__dirname + '/robot.html', 'utf8', function (err, html) {
console.log(html);
});When you run this code through brfs, it turns into:
var fs = require('fs');
process.nextTick(function () {(function (err, html) {
console.log(html);
})(null,"<b>beep boop</b>\n")});brfs looks for:
fs.readFileSync(pathExpr, enc=null)fs.readFile(pathExpr, enc=null, cb)fs.readdirSync(pathExpr)fs.readdir(pathExpr, cb)
Inside of each pathExpr, you can use
statically analyzable expressions and
these variables and functions:
__dirname__filenamepathif youvar path = require('path')firstrequire.resolve()
Just like node, the default encoding is null and will give back a Buffer.
If you want differently-encoded file contents for your inline content you can
set enc to 'utf8', 'base64', or 'hex'.
In async mode when a callback cb is given, the contents of pathExpr are
inlined into the source inside of a process.nextTick() call.
When you use a 'file'-event aware watcher such as
watchify, the inlined assets will be
updated automatically.
If you want to use this plugin directly, not through browserify, the api follows.
var brfs = require('brfs')Return a through stream tr inlining fs.readFileSync() file contents
in-place.
Optionally, you can set which opts.vars will be used in the
static argument evaluation
in addition to __dirname and __filename.
opts.parserOpts can be used to configure the parser brfs uses,
acorn.
For every file included with fs.readFileSync() or fs.readFile(), the tr
instance emits a 'file' event with the file path.
A tiny command-line program ships with this module to make debugging easier.
usage:
brfs file
Inline `fs.readFileSync()` calls from `file`, printing the transformed file
contents to stdout.
brfs
brfs -
Inline `fs.readFileSync()` calls from stdin, printing the transformed file
contents to stdout.
With npm do:
npm install brfs
then use -t brfs with the browserify command or use .transform('brfs') from
the browserify api.
Since brfs evaluates your source code statically, you can't use dynamic expressions that need to be evaluated at run time. For example:
// WILL NOT WORK!
var file = window.someFilePath;
var str = require('fs').readFileSync(file, 'utf8');Instead, you must use simpler expressions that can be resolved at build-time:
var str = require('fs').readFileSync(__dirname + '/file.txt', 'utf8');Another gotcha: brfs does not yet support ES module import statements. See brfs-babel for an experimental replacement that supports this syntax.
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