replace-async

Like string.replace, but with asynchronous, concurrent replacement.

install

npm install replace-async

example

const replace = require('replace-async')

replace('{{foo}} {{bar}}', regex, (done, match, ...etc) {
  somethingAsync(match, (err, newValue) => {
    done(err, newValue)
  })
}, (errors, result) => {

})

API

replace(string, pattern, replacement, [options], cb

• string
• pattern: string or RegExp
• replacement: string or function
• options: object
  • ignoreErrors: boolean, false By default, if any replacement functions fail, no result will be produced and replacement cleanup functions will be called. When true, produces a result even if there are errors and does not call cleanup functions.
• cb: (errors, result) => {}
  • errors: undefined or [] errors are placed at the index of their matching replacement (an error on the first replacement will be errors[0])
  • result: string or undefined result of replacement or undefined if there were any errors

replacement function

The arguments are just like string.replace, but begins with a node-style callback. If the asynchronous operation fails, pass done(err), otherwise pass the replacement value done(undefined, newValue).

You can return a function from the replacement function and it will be called for each replacement that has not called its callback yet if any replacements fail. This gives you opportunity to cancel/cleanup unfinished operations.

(done, match) => {
  const op = asyncOperation((err, result) => {
    done(err, result)
  })
  return () => op.cancel(done)
}