Search

Now, we will see how to query different type of Collection : Index, Series or data package

Auto description

Every point of access for any type of collection must expose a description document. It is a self descriptive XML document that declares the entry points for the search and the parameters that can be searched.

Let’s query the raw XML using curl

curl "https://catalog.terradue.com/mrossi/description"

Now, let’s use opensearch-client to format it in a human readable way

opensearch-client -d "https://catalog.terradue.com/mrossi/description"

name       O/M description
----       --- -----------
format       O content type of the query [*atom|json|atomeop|rdf]
q            O generic search terms
uid          O identifier of the entry within the collection
update       O timestamp < publication date (creation or update)
bbox         O spatial coverage in form minX,minY,maxX,maxY
geom         O spatial coverage in WKT form
grel         O spatial relationship [*intersects|contains|disjoint]
...

Warning

Do not confuse query filters and properties keywords!

Even if they may have a relationship, the name used for query filters do not always correspond exactly to the properties keywords extractor used in opensearch-client. For instance, when you filter on the identifier, you use the filter uid, when you request the identifier, you use identifier

Query with filters

We will perform the query using parameters

With curl

curl "https://catalog.terradue.com/mrossi/search?format=atom&q=processing&bbox=60,-30,70,-20"

The same with opensearch-client

opensearch-client -f atom -p q=processing -p bbox=60,-30,70,-20 "https://catalog.terradue.com/mrossi/search?format=json&q=processing&bbox=60,-30,70,-20" {}

Both previous commands will return the atom feed with the result queried.

Query specific properties

With opensearch-client, it is possible to query some specific entry properties according to the metadata model of the resource.

Note

See the opensearch-client doc section to know how to list all the metadata properties extractor available per metadata model.

Let’s take again our previous resource and ask for the identifiers, the spatial WKT and the publication date

opensearch-client -f atom -p q=processing -p bbox=60,-30,70,-20 "https://catalog.terradue.com/mrossi/search?format=json&q=processing&bbox=60,-30,70,-20" identifier,wkt,published