use underscore to exclude file and directories

Question

use underscore to exclude file and directories

i have a node.js / express application that uses i18next for the localization of the site.

currently i am pulling the list for this from a hard coded version: https://github.com/TZM/tzm-blade/blob/master/app/config/apps.coffee#L105 but would like to make this list up by reading the locales directory and then making up the list from that.

i would like to basically exclude the dev, README.md and config.json from being returned and just have the other directories so that i can then return the correct country local for example using the node-cldr library to extract the language display name as per https://github.com/papandreou/node-cldr#cldrextractlanguagedisplaynameslocaleidroot:

☺  node  ruby-2.0.0-p195 master 2253522""
> var cldr = require('cldr');
undefined
> cldr.extractLanguageDisplayNames('ru').ru;
'русский'
>

etc...

so far looking at the reject http://underscorejs.org/#reject collection i don't see how to remove these files and directories

  fs.readdir "./locales", (err,locales) ->
    results = []
    __.reject locales, (value, index, list) ->
      console.log value, index, list
      results.push value
    console.log results

any advice much appreciated on how best to do this using the reject function in underscore.

javascript
node.js
express
coffeescript
underscore.js

Answer 1

I'm not too familiar with coffeescript, but here's what you'd want (might require fixing up, as I don't know coffeescript):

EXCLUDE = [ 'dev', 'README.md', 'config.json' ]
results = __.reject locales, (value, index, list) ->
  return EXCLUDE.indexOf(value) == -1

_.reject returns a new list of any items that the iterator returns true for. In this case, if the item is not in the EXCLUDE list (indexOf === -1), the function returns true, and that item is part of the list it returns.