Quick 'Regenerating Views on Update' Mod Help

[Rob Law <ro...@flywheelnetworks.com>]

Hey,

I am trying to modify the data that gets sent to my ruby script when an
Update happens (as described here :
http://wiki.apache.org/couchdb/Regenerating_views_on_update).  I am hoping
to have couchdb alert me with the actual document that was updated or added
(like id, and attributes, etc), so that I can parse this update in my ruby
script and act accordingly.  So instead of the update_call looking like:

{"type":"updated","db":"DB_NAME"}

it would look like this:

{"type":"updated","db":"DB_NAME", "document":"_id" : "2342331232",
"data":"test"}

Is there any hope of getting that kind of data from couch on document
update?  I could just have my ruby script request changed documents or
something, but I thought it would be cleaner and more extensible if couch
just told my script the document that got updated.

Any tips would help.  Also, could someone direct me to the file and/or line
where that data gets sent to my script.  This is my first foray into Erlang
and I am trying to get into playing with couches internals, etc.

thanks

Rob

Re: Quick 'Regenerating Views on Update' Mod Help

[Rob Law <ro...@flywheelnetworks.com>]

Hey thanks for the fast response.  I'll get hacking away at this, and post
anything interesting (or any more questions) to the list.

thanks again

rob

On Thu, Dec 4, 2008 at 7:20 PM, Adam Kocoloski <ad...@gmail.com>wrote:

> Hi Rob, take a look at the 3rd clause of
> couch_db_update_notifier:handle_event (line ~55).  That's the code that
> sends update notifications to your Ruby script.  It handles
> couch_db_update_notifier:notify() calls, which you'll find in
> couch_server.erl and couch_db_updater.erl.
>
> From a technical perspective it would be easy enough to change the
> "updated" atoms sent in couch_db_updater to something a little more detailed
> (and extend the gen_event code to work with terms other than atoms at the
> same time).  I haven't used DbUpdateNotificationProcesses much myself so I'm
> not sure if there are higher-level design reasons why sending this more
> detailed info should be discouraged.  Best,
>
> Adam
>
>
> On Dec 4, 2008, at 4:51 PM, Rob Law wrote:
>
>  Hey,
>>
>> I am trying to modify the data that gets sent to my ruby script when an
>> Update happens (as described here :
>> http://wiki.apache.org/couchdb/Regenerating_views_on_update).  I am
>> hoping
>> to have couchdb alert me with the actual document that was updated or
>> added
>> (like id, and attributes, etc), so that I can parse this update in my ruby
>> script and act accordingly.  So instead of the update_call looking like:
>>
>> {"type":"updated","db":"DB_NAME"}
>>
>> it would look like this:
>>
>> {"type":"updated","db":"DB_NAME", "document":"_id" : "2342331232",
>> "data":"test"}
>>
>> Is there any hope of getting that kind of data from couch on document
>> update?  I could just have my ruby script request changed documents or
>> something, but I thought it would be cleaner and more extensible if couch
>> just told my script the document that got updated.
>>
>> Any tips would help.  Also, could someone direct me to the file and/or
>> line
>> where that data gets sent to my script.  This is my first foray into
>> Erlang
>> and I am trying to get into playing with couches internals, etc.
>>
>> thanks
>>
>> Rob
>>
>
>

Re: Quick 'Regenerating Views on Update' Mod Help

[Adam Kocoloski <ad...@gmail.com>]

Hi Rob, take a look at the 3rd clause of  
couch_db_update_notifier:handle_event (line ~55).  That's the code  
that sends update notifications to your Ruby script.  It handles  
couch_db_update_notifier:notify() calls, which you'll find in  
couch_server.erl and couch_db_updater.erl.

 From a technical perspective it would be easy enough to change the  
"updated" atoms sent in couch_db_updater to something a little more  
detailed (and extend the gen_event code to work with terms other than  
atoms at the same time).  I haven't used DbUpdateNotificationProcesses  
much myself so I'm not sure if there are higher-level design reasons  
why sending this more detailed info should be discouraged.  Best,

Adam

On Dec 4, 2008, at 4:51 PM, Rob Law wrote:

> Hey,
>
> I am trying to modify the data that gets sent to my ruby script when  
> an
> Update happens (as described here :
> http://wiki.apache.org/couchdb/Regenerating_views_on_update).  I am  
> hoping
> to have couchdb alert me with the actual document that was updated  
> or added
> (like id, and attributes, etc), so that I can parse this update in  
> my ruby
> script and act accordingly.  So instead of the update_call looking  
> like:
>
> {"type":"updated","db":"DB_NAME"}
>
> it would look like this:
>
> {"type":"updated","db":"DB_NAME", "document":"_id" : "2342331232",
> "data":"test"}
>
> Is there any hope of getting that kind of data from couch on document
> update?  I could just have my ruby script request changed documents or
> something, but I thought it would be cleaner and more extensible if  
> couch
> just told my script the document that got updated.
>
> Any tips would help.  Also, could someone direct me to the file and/ 
> or line
> where that data gets sent to my script.  This is my first foray into  
> Erlang
> and I am trying to get into playing with couches internals, etc.
>
> thanks
>
> Rob