stream.Readable
from a URI stringThis high-level module accepts a URI string and returns a Readable
stream
instance. There is built-in support for a variety of "protocols", and it's
easily extensible with more:
Protocol | Description | Example |
---|---|---|
data |
Data URIs | data:text/plain;base64,SGVsbG8sIFdvcmxkIQ%3D%3D |
file |
File URIs | file:///c:/windows/example.ini |
ftp |
FTP URIs | ftp://ftp.kernel.org/pub/site/README |
http |
HTTP URIs | http://www.example.com/path/to/name |
https |
HTTPS URIs | https://www.example.com/path/to/name |
To simply get a stream.Readable
instance from a file:
URI, try something like:
import { getUri } from 'get-uri';
// `file:` maps to a `fs.ReadStream` instance…
const stream = await getUri('file:///Users/nrajlich/wat.json');
stream.pipe(process.stdout);
When you pass in a URI in which the resource referenced does not exist on the
destination server, then a NotFoundError
will be thrown. The code
of the
error instance is set to "ENOTFOUND"
, so you can check for that value
to detect when a bad filename is requested:
try {
await getUri('http://example.com/resource.json');
} catch (err) {
if (err.code === 'ENOTFOUND') {
// bad file path requested
} else {
// something else bad happened...
throw err;
}
}
When calling getUri()
with the same URI multiple times, the get-uri
module
supports sending an indicator that the remote resource has not been modified
since the last time it has been retreived from that node process.
To do this, define a cache
property on the "options object" argument
with the value set to the stream.Readable
instance that was previously
returned. If the remote resource has not been changed since the last call for
that same URI, then a NotModifiedError
instance will be thrown with its
code
property set to "ENOTMODIFIED"
.
When the "ENOTMODIFIED"
error occurs, then you can safely re-use the
results from the previous getUri()
call for that same URI:
// First time fetches for real
const stream = await getUri('http://example.com/resource.json');
try {
// … some time later, if you need to get this same URI again, pass in the
// previous `stream.Readable` instance as `cache` option to potentially
// have an "ENOTMODIFIED" error thrown:
await getUri('http://example.com/resource.json', { cache: stream });
} catch (err) {
if (err.code === 'ENOTMODIFIED') {
// source file has not been modified since last time it was requested,
// so you are expected to re-use results from a previous call to `getUri()`
} else {
// something else bad happened...
throw err;
}
}
A uri
is required. An optional options
object may be passed in:
cache
- A stream.Readable
instance from a previous call to getUri()
with the same URI. If this option is passed in, and the destination endpoint has not been modified, then an ENOTMODIFIED
error is thrownAny other options passed in to the options
object will be passed through
to the low-level connection creation functions (http.get()
, ftp.connect()
,
etc).
Returns a stream.Readable
instance to read the resource at the given uri
.
(The MIT License)
Copyright (c) 2014 Nathan Rajlich <nathan@tootallnate.net>
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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