Actually, he is...
if doc.events is an object, then the object might not actually be
copied, but only a reference.
If you change
var events = doc.events;
to
var events = clone doc.event;
Does that fix it?
On 20/04/2011 10:59 PM, Jan Lehnardt wrote:
On 20 Apr 2011, at 14:11, Nils Breunese wrote:
Hello all,
I recently upgraded to CouchDB 1.0.2 for development and found some of our view map
functions broke. Apparently it's no longer possible to modify data a doc in a view
function before emitting. I found "Documents are now sealed before being passed to
map functions." in the changelog for 1.0.2.
This is an example of a map function which no longer works under 1.0.2:
----
function(doc) {
if(doc.type === 'schedule') {
var events = doc.events;
if (events) {
events.forEach(function(event) {
var broadcasters = event.broadcasters;
if (broadcasters) {
broadcasters.forEach(function(broadcaster) {
if(broadcaster === 'VPRO') {
event.channel = doc.channel;
event.channelName = doc.channelName;
emit(event.end, event);
}
});
}
});
}
}
}
This creates a deep copy before modifying event properties. It works, but it
looks ugly to me. Is this the way to go or is there a cleaner way?
I use JSON.parse(JSON.stringify(doc)) but that is essentially the same :)
The reason that doc modifications work were an artefact of a bug in
Spidermonkey that finally got resolved. You shouldn't rely on being able to
modify a doc in map functions.
That said, I'm surprised you get this error as you are not assigning anything
do doc.events. Unless I got wrong how chaining in JS works, this shouldn't be a
problem:
js> var a = {a:1};
js> seal(a);
js> a.a = 2;
typein:4: Error: a.a is read-only
js> var b = a.a;
js> print(b);
1
js> b = 2
2
js>
Cheers
Jan
