grunt-sri
v0.2.0
Published
Client-side caching & SRI generation for Grunt
Downloads
5,406
Readme
grunt-sri
This tool generates a JSON manifest of file hashes & sub-resource integrity data.
Install
npm install --save-dev grunt-sri
Usage
Add the following to your Gruntfile.js
:
module.exports = function (grunt) {
"use strict";
grunt.loadNpmTasks("grunt-sri");
grunt.initConfig({
"sri": {
// Use the default settings for *everything* in ./public/css
"bobsDefaultTask": {
"src": [
"public/**/*.css"
]
},
// Create a second manifest with custom settings
"janesCustomTask": {
"options": {
"algorithms": ["sha256"],
"dest": "./public/sri-directives.json",
"targetProp": "payload"
},
"files": [
{
src: "public/css/example.css",
type: "text/css",
id: "cssfile1"
},
{
src: "public/css/other.css"
}
]
}
}
});
grunt.registerTask("default", ["sri"]);
};
Run the command grunt
. The manifest file will be created.
Options
- String dest: Target JSON file.
Default"./payload.json"
- Boolean merge: Merge results with existing JSON file.
Defaultfalse
(overwrite) - Array algorithms: List of desired hash algorithms.
Default["sha256", "sha512"]
- String targetProp: Target JS object property name.
Defaultnull
- Boolean pretty: Stringify the JSON output in a pretty format.
Defaultfalse
Manifest
Metadata is stored in JSON format.
- The default manifest dest is
./payload.json
. - File paths are relative to the CWD of Grunt.
This should be the project root. - File identifiers are prefixed with the "@" symbol.
If no ID is specified, the path will be used.
Example:
{
"@cssfile1": {
"path": "public/css/example.css",
"type": "text/css",
"integrity": "type:text/css sha256-XXXX sha512-XXXXXXXX",
"hashes": {
"sha256": "XXXX",
"sha512": "XXXXXXXX"
}
}
}
Implementation
Data from the manifest can be loaded into markup.
Use the integrity
property for SRI integrity attributes, a hash from hashes
as a URL parameter for client-side caching, etc.
PHP
// In production, consider compiling JSON to PHP assoc arrays
$payload = json_decode(file_get_contents("./payload.json"), true);
$sri = function (id) {
return $payload["payload"][id];
}
$element = "<link
href='/style.css?cache={ sri("@cssfile1")["hashes"]["sha256"] }'
integrity='{ $sri("@cssfile1")["integrity"] }'
rel='stylesheet'>";
JavaScript
Note: Node apps should use subresource or handlebars-helper-sri, which don't require a build step.
// ES6
var payload = require("./payload.json");
var sri = (id) => payload.payload[id];
var element = `<link
href='/style.css?cache=${ sri("@cssfile1").hashes.sha256 }'
integrity='${ sri("@cssfile1").integrity }'
rel='stylesheet'>`;
SemVer
This tool follows SemVer from v0.1.0, as SRI is now a W3C recommendation.
Changes to the V1 SRI spec will be tracked with minor releases.