A middleware pattern for polkadot
npm install polkadot-middleware``js`
npm i polkadot-middleware
So you're using the awesome polkadot server, but you're missing that sweet middleware action – it's a pain to have to compose all those functions yourself, isn't it?
`js
polkadot(
handleErrors(
setCacheControl(
(req, res) => 'Sup dawg'
)
)
).listen(8080)
function handleErrors(next) {
return async(req, res) => {
try {
return await next(req, res)
} catch (err) {
res.statusCode = 500
return err.message || err
}
}
}
function setCacheControl(next) {
return async(req, res) => {
res.setHeader(Cache-Control, public, max-age= + 3600)`
return next(req, res)
}
}
Well, until TC39 figures out the pipeline operator, you can use this library to give yourself that sweet linear middleware experience.
`js
const polkadot = require('polkadot')
const middleware = require('polkadot-middleware')
middleware(
polkadot,
handleErrors,
setCacheControl,
(req, res) => 'Sup dawg'
).listen(8080)
``