express-response-filter
v0.5.2
Published
Express middleware for filtering-out parts of JSON responses based on the `fields` query-string.
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Express Response Filter Middleware
This Express Middleware will allow you to send a subset of a JSON object
instead of an entire object from your HTTP services. To do so, your services
will begin accepting the ?fields=
query-string that, using a simple language,
will specify which fields and sub-feelds to keep and which to ignore.
If you've used the Google APIs, provided a ?fields=
query-string to get a
Partial Response,
and wanted to do the same for your own server, now you can do so with this
middleware.
Underneath, this middleware uses json-mask. Use it directly without this middleware if you need more flexibility.
Installation
npm install express-response-filter --save
Usage
var express = require('express')
, responseFilter = require('express-response-filter')
, app = express()
app.use(responseFilter({
filter: ["test"],
}))
app.get('/', function (req, res, next) {
// keyword filter, not influenced by user query input
req.customFilter = ["id", "password", "token"]; // concat to opt.filters array
res.json({
firstName: 'Mohandas'
, lastName: 'Gandhi'
, aliases: [{
firstName: 'Mahatma'
, lastName: 'Gandhi'
}, {
firstName: 'Bapu'
}]
})
})
app.listen(4000)
Let's test it:
$ curl 'http://localhost:4000'
{"firstName":"Mohandas","lastName":"Gandhi","aliases":[{"firstName":"Mahatma","lastName":"Gandhi"},{"firstName":"Bapu"}]}
$ # Let's just get the first name
$ curl 'http://localhost:4000?fields=lastName'
{"lastName":"Gandhi"}
$ # Now, let's just get the first names directly as well as from aliases
$ curl 'http://localhost:4000?fields=firstName,aliases(firstName)'
{"firstName":"Mohandas","aliases":[{"firstName":"Mahatma"},{"firstName":"Bapu"}]}
Note: take a look at /example
.
Syntax
Look at json-mask for the available syntax of the fields
param.
Options
query
specifies the query-string to use. Defaults to fields
prefix
specifies the query-string prefix.
filter
specifies the filter before json-masked. Array | Function is allowed
app.use(responseFilter({
query: 'filter'
}))
License
MIT. See LICENSE