@murithigeo/edr-client

This library provides a convinient way to make requests to EDR Servers

Status

This library has not reached 1.0 and is under active development. If you have a question or request, please create an issue.

API

Creating a new Client

let cli = await new EdrClient().create(
  "https://ogc-edr-api.murithigeo.deno.net/",
);

Load the conformance classes implemented by server

// The Client will auto prefer HTTP POST support if it finds the class http://www.opengis.net/spec/ogcapi-edr-1/1.1/conf/queries in the list
let confClasses = await cli.conformance();

Load the OpenAPI document powering the server

let openapi = await cli["service-desc"]();

let Loading all collections

let collections = await cli.collections();

Find the collection you want

let collection = collections.find((e) => e.id === "mountains");

Loading a specific collection without link object trasversal

let collection = await new CollectionQuery().create(
  "https://ogc-edr-api.murithigeo.deno.net/collections/mountains",
);
// An instance can also be loaded the same way
let instance = await new CollectionQuery().create(
  "https://ogc-edr-api.murithigeo.deno.net/collections/mountains/",
);

Load all items using certain criteria

let query = collection
  .items()
  .where(...args)
  .execute();

Query specific itemId

let item = query
  .queryItem("Mt Kenya")
  .where(...args)
  .execute();

Load all locations (This expects the endpoint /locations to return a GeoJSON FeatureCollection)

let locations = collection
  .locations()
  .where(...args)
  .execute();

Query specific locations

let res = await locations
  .queryLocations()
  ?.where(...args)
  .execute();

Query trajectory

let res = await collection
  ?.trajectory()
  .where("coords", "LINESTRING(30 2, 40 3)")
  .where(...args)
  .execute();

Making Requests Most query types have a method execute which returns an HTTP Response object. It does not parse the response

Exceptions are the /locations and /items endpoint which parse the response due to certain expectations

Where Method

The where method can be chained with each successive value overwriting a previously set value if any

query.where("bbox", [20, 1, 3, 4]).where("datetime", "eq", "2021");

HTTP Method

As mentioned in the conformance section, POST requests will be preferred via checking for the presence of a confClass. However, this can be overriden via calling

query.where("method", "POST");
// or
query.where("method", "GET");

Parameters

For each data_query, you can restrict the spatiotemporal bounds of the response using the method where

Datetime

Return data whose temporal field value lies between two dates

query.where("datetime", "between", [
  "2000-01-01T00:00:00Z",
  "2026-03-24T23:59:99Z",
]);

Return data whose temporal value is later than the input

query.where("datetime", "gte", "2000-01-01T00:00:000Z");

Return data whose temporal is earlier than the input

query.where("datetime", "lte", "2026-03-23T00:00:00Z");

These two methods are equivalent

query
  .where("datetime", "gte", "2001-01-01")
  .where("datetime", "lte", "2026-03-24");

// Is the same as
query.where("datetime", "between", ["2001-01-01", "2026-03-24"]);

Return data whose temporal value is equivalent to input

query.where("datetime", "eq", "2000-01-01");

Z (Elevation)

Return data whose elevation field lies between a range

query.where("z", "between", [0, 100]);

Return data whose elevation is in a list of heights

query.where("z", "in", [-10, -20]);

Filter data using a arithmetic sequence

// The starting point
let min = 10,
  // Number of intervals
  num = 3,
  //Size between intervals
  step = 10;
query.where("z", "interval", {
  min,
  num,
  step,
});

Get data for single value

query.where("z", "=", 1000);

Note: Each successive call of the where("z",...args) will overwrite the z param value

Parameter-name

The standard specifies that if no parameter-name value is defined, then data incorporating all parameters is returned. Therefore, you can skip invoking query.where("parameter-name",...args) if you want all of them

Request specific parameters

query.where("parameter-name", "in", ["temperature", "cloudBase"]);

Request all parameters except those specified

query.where("parameter-name", "not in", ["depth", "pressure"]);

f

query.where("f", "GeoJSON");

Bbox

For query_type's supporting bbox

// Use a Bounding Box
query.where("bbox",[33, -4, 41, 5])

// Use a GeoJSON Feature, FeatureCollection, Geometry
// Internally calls @turf/bbox to get the Bounding Box
query.where("bbox",{type:"Point",coordinates:[...]})

Coords

query_type: corridor,trajectory,position,radius, area

There are two ways to go about it

// Use a Well Known Text Representation of Geometry
// string converted to Geometry via betterknown
query.where("coords", "POINT(36 1)");

// Use a GeoJSON Geometry Object
query.where("coords", { type: "Point", coordinates: [36, 1] });

Each query type has specific allowed GeoJSON Geometry Types and which improve intellisense

// Position
query.where("coords", "POINT(...)"); // Correct
query.where("coords", "LINESTRING(...)"); // Throws Error

Resolution-[x|y|z]

For the area query type, you can also specify sampling intervals via the resolution-[x|y]

query.where("resolution-x", 10).where("resolution-y", 20);

The corridor query type additionally allows the z-axis sampling

query.where("resolution-z", 20);

Corridor Specific Parameters

Corridor-Height and Height-Units

query.where("corridor-height", 20000, "feet");

corridor-width and width-units

query.where("corridor-width", 1000, "meters");

Radius Specific Params

within and within-units

query.where("within", 1000, "meters");