Node.js从数据库加载脚本

Question

I would like to add a «dynamic» part of my node backend, so that I can easily add/edit simple JS code snippets quickly. Ideally the JavaScript code for these snippets would be stored in the database, and loaded («required») directly from the db.

If the code in the db changes, these change would take effect immediately - so the script should be loaded on every request.

Is there a way to achieve this using Node.js?

Answer 1

You store the code as text entries in the database and retrieve it using database calls. Doing that reactively is a question of its own and will depend on which database you are using (for instance, reacting to the oplog in Mongo).

After retrieving the text you will need to execute the code somehow. You can do this using eval in JavaScript, but you need to trust the code! You simply have to call eval(codeRetrievedFromDb); in javascript

Example :

var str_fun = "function custom_fun(arg) { return 'hello'; }";

eval(str_fun);

function usefun(x)
{
  var res = custom_fun(x);
  //print hello
  console.log(res);
}

For the second part of your question, I suggest to create a polling function accessing the database every X seconds.