Description

The OpenSearch Endpoint provides a

DDF

endpoint that a client accesses to send query parameters and receive search results.

This endpoint uses the input query parameters to create an OpenSearch query. The client does not need to specify all of the query parameters, only the query parameters of interest.

This endpoint is a JAX-RS RESTful service and is compliant with the CDR IPT BrokeredSearch, CDR IPT OpenSearch, and OpenSearch Specifications. For more information on its parameters view the OpenSearch Description Document section below

Using the OpenSearch Endpoint

Once installed, the OpenSearch endpoint is accessible from http://<DDF_HOST>:<DDF_PORT>/services/catalog/query.

Using the endpoint

From Code:

The OpenSearch specification defines a file format to describe an OpenSearch endpoint. This file is XML-based and is used to programatically retrieve a site's endpoint, as well as the different parameter options a site holds. The parameters are defined via the OpenSearch and CDR IPT Specifications.

From a Web Browser:

Many modern web browsers currently act as OpenSearch clients. The request call is an HTTP GET with the query options being parameters that are passed.

Example of an OpenSearch request:

http://<ddf_host>:8181/services/catalog/query?q=Predator

This request performs a full-text search for the phrase 'Predator' on the DDF providers and provides the results as Atom-formatted XML for the web browser to render.

Parameter List

Main OpenSearch Standard

OS Element	HTTP Parameter	Possible Values	Comments
searchTerms	q	URL-encoded string	Complex contextual search string.
count	count	integer >= 0	Maximum # of results to retrieve default: 10
startIndex	start	integer >= 1	Index of first result to return. default: 1 This value uses a one based index for the results.
format	format	requires a transformer shortname as a string, possible values include when available atom html kml see Included Query Response Transformers for more possible values	default: atom

Temporal Extension

OS Element	HTTP Parameter	Possible Values	Comments
start	dtstart	RFC-3399-defined value	yyyy-MM-dd'T'HH:mm:ss.SSSZZ
end	dtend	RFC-3399-defined value	yyyy-MM-dd'T'HH:mm:ss.SSSZZ

The start and end temporal criteria must be of the format specified above. Other formats are currently not supported. Example: 2011-01-01T12:00:00.111-04:00.

The start and end temporal elements are based on modified timestamps for a metacard.

Geospatial Extension

These Geospatial query parameters are used to create a geospatial INTERSECTS query, where INTERSECTS = geometries that are not DISJOINT of the given geospatial parameter.

OS Element	HTTP Parameter	Possible Values	Comments
lat	lat	EPSG:4326 decimal degrees	Expects a latitude and a radius to be specified.
lon	lon	EPSG:4326 decimal degrees	Expects a longitude and a radius to be specified.
radius	radius	Meters along the Earth's surface > 0	Used in conjunction with lat and lon query parameters.
polygon	polygon	clockwise lat lon pairs ending at the first one	example: -80, -170, 0, -170, 80, -170, 80, 170, 0, 170, -80, 170, -80, -170 According to the OpenSearch Geo Specification this is deprecated. Use geometry instead.
box	bbox	4 comma-separated EPSG:4326 decimal degrees	west, south, east, north
geometry	geometry	WKT Geometries: POINT, POLYGON, MULTIPOINT, MULTIPOLYGON	Examples: POINT(10 20) where 10 is the longitude and 20 is the latitude. POLYGON ( ( 30 10, 10 20, 20 40, 40 40, 30 10 ) ). 30 is longitude and 10 is latitude for the first point. Make sure to repeat the starting point as the last point to close the polygon.

Extensions

OS Element

HTTP Parameter

Possible Values

Comments

sort

sbfield: 'date' or 'relevance'

sborder: 'asc' or 'desc'

sort=<sbfield>:<sborder> default: relevance:desc

Sorting by date will sort the effective date.

maxResults

mr

Integer >= 0

Maximum # of results to return.

If count is also specified, the count value will take precedence over the maxResults value

maxTimeout

mt

Integer > 0

Maximum timeout (milliseconds) for query to respond

default: 300000 (5 minutes)

Federated Search

OS Element

HTTP Parameter

Possible Values

Comments

routeTo

src

(varies depending on the names of the sites in the federation)

comma delimited list of site names to query.

Also can specify src=local to query the local site.

If src is not provided, the default behavior is to execute an enterprise search to the entire federation.

DDF Extensions

OS Element	HTTP Parameter	Possible Values	Comments
dateOffset	dtoffset	integer > 0	Specifies an offset, backwards from the current time, to search on the modified time field for entries. Defined in milliseconds.
type	type	nitf	Specifies the type of data to search for.
version	version	20,30	Comma-delimited list of version values to search for.
selector	selector	//namespace:example,//example	Comma-delimited list of XPath string selectors that narrow down the search.

Supported Complex Contextual Query Format

The contextual query format is based on the "IC/DoD Keyword Query Language Specification, V2.0" DRAFT 9/4/2012.

The OpenSearch Endpoint supports the following operators: AND, OR, and NOT. These operators are case sensitive. Implicit ANDs are also supported.

Using parenthesis to change the order of operations is supported. Using quotes to group keywords into literal expressions is supported.

The following EBNF describes the grammar used for the contextual query format.

OpenSearch Complex Contextual Query EBNF

keyword query expression = optional whitespace, term, {boolean operator, term}, optional whitespace;
boolean operator = or | not | and;
and = (optional whitespace, "AND", optional whitespace) | mandatory whitespace;
or = (optional whitespace, "OR", optional whitespace);
not = (optional whitespace, "NOT", optional whitespace);
term = group | phrase | keyword;
phrase = optional whitespace, '"', optional whitespace, keyword, { optional whitespace, keyword}, optional whitespace, '"';
group = optional whitespace, '(', optional whitespace, keyword query expression, optional whitespace, ')';
optional whitespace = {' '};
mandatory whitespace = ' ', optional whitespace;
valid character = ? any printable character ? - ('"' | '(' | ')' | " ");
keyword = valid character, {valid character};

Installation and Uninstallation

The OpenSearch Endpoint can be installed and uninstalled using the normal processes described in the Configuration section.

Configuration

The OpenSearch Endpoint has no configurable properties. It can only be installed or uninstalled.

OpenSearch Description Document

The OpenSearch Description Document is an XML file is found inside of the OpenSearch Endpoint bundle and is named ddf-os.xml

Implementation Details

Imported Services

Registered Interface	Availability	Multiple
`ddf.catalog.CatalogFramework`	required	false
`ddf.catalog.filter.FilterBuilder`	required	false

Exported Services

Registered Interface	Service Property	Value
`ddf.catalog.util.DdfConfigurationWatcher`

Example Output

The default output for OpenSearch is Atom. Detailed documentation on Atom output, including query result mapping and example output, can be found on the Atom Query Response Transformer page.

Distributed Data Framework 2.2.X

OpenSearch Endpoint