Async call generates " Error: Can't wait without a "fiber", even with _wrapAsync - meteor

Question

I've been having a problem using an RSS parser in meteor. It's an async call, so it needs ot be wrapped, however it still doesn't seem to work. I presume this is because the anonymous on('readable' function is outside the fiber, but I can't see how to resolve it.
var FeedParser = Meteor.require('feedparser');
var request = Meteor.require('request');
function getBlog(url, parameter, id){
request(parameter)
.on('error', function (error) {
console.error(error);
})
.pipe(new FeedParser())
.on('error', function (error) {
console.error(error);
})
.on('readable', function () {
var stream = this,
item;
while (item = stream.read()) {
Items.insert(new_item);
}
});
}
var wrappedGetBlog = Meteor._wrapAsync(getBlog);
Meteor.methods({
blog: function (url, parameter, id) {
console.log('parsing blog');
var items = wrappedGetBlog(url, parameter, id);
}
});

Answer 1

Meteor._wrapAsync() expects the wrapped function to return error and result to a callback. Your function, getBlog(), does not do that so _wrapAsync is not the right approach.
I have wrapped that function before but used a Future.
That approach allowed me to call feedparser from a Meteor.method(), which doesn't allow async functions, but you are also trying to do an insert inside the readable event. I think that insert will complain if it is not in a fiber. Maybe like this would also be necessary:
var r = request( parameter );
r.on( 'response' , function(){
var fp = r.pipe( new FeedParser() ); //need feedparser object as variable to pass to bindEnvironment
fp.on('readable', Meteor.bindEnvironment(
function () {
var stream = this,
item;
while (item = stream.read()) {
Items.insert(new_item);
}
}
, function( error ){ console.log( error );}
, fp // variable applied as `this` inside call of first function
));
});
Fibers is another option...
var Fiber = Npm.require( "fibers" );
.on('readable', function () {
var stream = this,
item;
while (item = stream.read()) {
Fiber( function(){
Items.insert(new_item);
Fiber.yield();
}).run();
}
});