User Agent Bag
Parse User-Agents per RFC7231. Doesn't handle all the weirdness around real User-Agents, just parses things per the spec.
const UserAgentBag = require("user-agent-bag");
const firefoxBag = new UserAgentBag(
"Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:47.0) Gecko/20100101 Firefox/47.0"
);
firefoxBag.get("Mozilla");
// => '5.0'
firefoxBag.has("Gecko");
// => true
const customBag = new UserAgentBag([
["Foo", "bar"],
["Baz", null],
]);
customBag.toString();
// => 'Foo/bar Baz'
API documentation
new UserAgentBag(string)
Creates a new UserAgentBag
by parsing string
as a User-Agent per RFC7231. string
must have a length of 256 characters or less (this limit may be configurable in the future). If there are any errors in parsing, the bag will be empty.
const validBag = new UserAgentBag("Foo/1.2");
validBag.get("Foo");
// => '1.2'
const invalidStringBag = new UserAgentBag(
"Foo/1.2 IsInvalidBecauseVersionIsMissing/"
);
invalidStringBag.get("Foo");
// => undefined
new UserAgentBag(iterable)
Creates a new UserAgentBag
from iterable
. Elements of iterable
are key-value pairs.
const bagFromEntries = new UserAgentBag([
["Foo", "1.2"],
["Bar", null],
]);
bagFromEntries.toString();
// => 'Foo/1.2 Bar'
const myMap = new Map();
myMap.set("Baz", "5");
myMap.set("Qux", "6");
const bagFromMap = new UserAgentBag(myMap);
bagFromMap.toString();
// => 'Baz/5 Qux/6'
UserAgentBag.prototype.entries()
Returns an iterable yielding each of the product-version pairs in the bag. Like Map.prototype.entries
.
const bag = new UserAgentBag("Foo/1.2 Bar Baz/3.4");
for (const [product, version] of bag.entries()) {
console.log(product + " version " + version);
}
// Logs:
// Foo version 1.2
// Bar version null
// Baz version 3.4
UserAgentBag.prototype.get(product)
Returns the version of the product. If product
is in the bag multiple times, only the first value is returned. If no version is specified, null
is returned. If the product is missing from the bag, undefined
is returned.
const bag = new UserAgentBag("Foo/1.2 Bar/4.5 Bar/6.7 Baz");
bag.get("Foo");
// => '1.2'
bag.get("Bar");
// => '4.5'
bag.get("Baz");
// => null
bag.get("missing");
// => undefined
bag.get("foo");
// => undefined
UserAgentBag.prototype.getAll(product)
Returns all specified versions of the product as an array. null
represents the absence of a version. If the product is missing from the bag, the empty array is returned.
const bag = new UserAgentBag("Foo/1.2 Bar/4.5 Bar/null");
bag.getAll("Foo");
// => ['1.2']
bag.getAll("Bar");
// => ['4.5', null]
bag.get("missing");
// => []
UserAgentBag.prototype.has(product)
Returns true
if product
is in the bag, false
otherwise.
const bag = new UserAgentBag("Foo/1.2 Bar");
bag.has("Foo");
// => true
bag.has("Bar");
// => true
bag.has("missing");
// => false
UserAgentBag.prototype.size()
Returns the number of products in the bag.
const bag = new UserAgentBag("Foo/1.2 (ignored comment) Bar/3 Bar/4");
bag.size();
// => 3
UserAgentBag.prototype.toString()
Converts the bag to a string. Useful when constructing your own User-Agents.
const bag = new UserAgentBag([
["Foo", "1.2"],
["Bar", null],
]);
bag.toString();
// => 'Foo/1.2 Bar'