{"action":"opened","issue":{"url":"https://api.github.com/repos/Homebrew/homebrew-bundle/issues/87","labels_url":"https://api.github.com/repos/Homebrew/homebrew-bundle/issues/87/labels{/name}","comments_url":"https://api.github.com/repos/Homebrew/homebrew-bundle/issues/87/comments","events_url":"https://api.github.com/repos/Homebrew/homebrew-bundle/issues/87/events","html_url":"https://github.com/Homebrew/homebrew-bundle/issues/87","id":90399690,"number":87,"title":"Add DSL for conditional installation","user":{"login":"mikemcquaid","id":125011,"avatar_url":"https://avatars.githubusercontent.com/u/125011?v=3","gravatar_id":"","url":"https://api.github.com/users/mikemcquaid","html_url":"https://github.com/mikemcquaid","followers_url":"https://api.github.com/users/mikemcquaid/followers","following_url":"https://api.github.com/users/mikemcquaid/following{/other_user}","gists_url":"https://api.github.com/users/mikemcquaid/gists{/gist_id}","starred_url":"https://api.github.com/users/mikemcquaid/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mikemcquaid/subscriptions","organizations_url":"https://api.github.com/users/mikemcquaid/orgs","repos_url":"https://api.github.com/users/mikemcquaid/repos","events_url":"https://api.github.com/users/mikemcquaid/events{/privacy}","received_events_url":"https://api.github.com/users/mikemcquaid/received_events","type":"User","site_admin":true},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-06-23T14:05:52Z","updated_at":"2015-06-23T14:05:52Z","closed_at":null,"body":"I might have a `Brewfile` with `cask 'java'`. Problem is, I want to be able to use this on systems which may already have Java installed from somewhere other than `brew cask`.\r\n\r\nPerhaps it'd be nice to have an API like:\r\n```ruby\r\ncask 'java', unless: ''/usr/libexec/java_home --failfast\"\r\n```\r\nthat will only install Java if that command fails. If the `cask` is already installed it should still upgrade it."}}