Filter a rest service by category or field - json

Question

I am using the extension library's rest control to provide a json data feed. Is it possible to filter by a category or a field with a URL parameter?
I understand that I can use a search string "&search=something" but that can provide me with erroneous results. I have tried searching for a field equal to some value but that doesn't seem to work for me.
If I cannot do this with the rest control, is it possible with Domino Data Services?

Answer 1

You can filter by a category or field value in a viewJsonService if you add ?keys=yourValue to URL.
The REST service returns the same documents as you would get with view.getAllDocumentsByKey("yourValue").
Default is non-exact-match filtering which means that only the beginning of column value has to match. If you want the exact match then add &keysexactmatch=true to URL which would be the equivalent to view.getAllDocumentsByKey("yourValue", true).
Example:
Assuming, we have a view "Forms" with a first sorted column "Form".
With the REST service
<xe:restService
id="restService1"
pathInfo="DocsByForm">
<xe:this.service>
<xe:viewJsonService
viewName="Forms"
defaultColumns="true">
</xe:viewJsonService>
</xe:this.service>
</xe:restService>
and the URL
http://server/database.nsf/RestServices.xsp/DocsByForm?keys=Memo&keysexactmatch=true
we'd get all documents with Form="Memo" as JSON
[
{
"#entryid":"7-D5029CB83351A9A6C1257D820031E927",
"#unid":"D5029CB83351A9A6C1257D820031E927",
"#noteid":"11DA",
"#position":"7",
"#siblings":14,
"#form":"Memo",
"Form":"Memo",
... other columns ...
},
... other documents
]
We'd get the same result if the first column is categorized.