[Couchdb Wiki] Update of Formatting with Show and List by ChrisAnderson
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http://wiki.apache.org/couchdb/Formatting_with_Show_and_List
The comment on the change is:
documented show functions
New page:
The basics of formatting documents using `show` and `list` functions. These
functions convert documents and views, respectively, into non-JSON formats. The
rows of each view are processed individually, which keeps long lists from
becoming memory hogs.
They are designed to be cacheable. CouchDB handles generating Etags for show
and list responses.
Show and list functions are side effect free and idempotent. They can not make
additional HTTP requests against CouchDB. Their purpose is to render JSON
documents in other formats.
== Showing Documents ==
Show functions are stored in your design document, under the `shows` key.
Here's an example set of show functions:
{{{
{
_id : _design/examples,
shows : {
posts : function(doc, req) {... return responseObject;},
people : function(doc, req) { ... }
}
}}}
These functions could be queried like this:
{{{
GET /db/_show/examples/posts/somedocid
GET /db/_show/examples/people/otherdocid
GET /db/_show/examples/people/otherdocid?format=xmldetails=true
}}}
The show function is run with two arguments, the first is the document
corresponding to the requested docid. The second argument is the req object,
which contains information about the query string, Accept headers, and other
per-request information.
The show function returns a JSON object of the same format of the _external
response. See ExternalProcesses for further explanation of the `req` object as
well as documentation about the response.
== Listing Views ==
[Couchdb Wiki] Update of Formatting with Show and List by ChrisAnderson
Dear Wiki user,
You have subscribed to a wiki page or wiki category on Couchdb Wiki for
change notification.
The following page has been changed by ChrisAnderson:
http://wiki.apache.org/couchdb/Formatting_with_Show_and_List
The comment on the change is:
documentation for list funs
--
== Listing Views ==
+ List funcitons are stored under the `lists` key of design documents. Here's
an example desgin doc with list functions:
+
+ {{{
+ {
+ _id : _design/examples,
+ views {
+ posts-by-date : function(doc){...},
+ posts-by-tag : function(doc){...},
+ people-by-name : function(doc) {...}
+ },
+ lists : {
+ index-posts : function(head, row, req, row_info) {...},
+ browse-people : function(head, row, req, row_info) { ... }
+ }
+ }}}
+
+ These lists are run by querying URLs like:
+
+ {{{
+ GET /db/_list/examples/index-posts/posts-by-date?descending=truelimit=10
+
+ GET /db/_list/examples/index-posts/posts-by-tag?key=howto
+
+ GET /db/_list/examples/browse-people/people-by-name?startkey=[a]limit=10
+
+ }}}
+
+ List functions have a more interesting signature, as they are passed the head
of the view on first invocation, then each row in turn, then called once
finally for the tail of the view. They also have the ability to abort iteration
early, which is handy for some filtering operations.
+
+ Example list function:
+
+ {{{
+ function(head, row, req, row_info) {
+ if (head) {
+ return phead: +JSON.stringify(head)+/pul;
+ } else if (row) {
+ return li+JSON.stringify(row)+/li;
+ } else {
+ return /ulh4the tail/h4
+ }
+ }
+ }}}
+
+ Hopefully that gets you enough to get started. For a more complete set of
examples, see the CouchDB test suite, especially show_documents.js and
list_views.js
+
