1. SNOWTAM Trial: REST Interface

2. AIXM XML Developers' Seminar 2 Contents Digital-SNOWTAM Trial Introduction REST Introduction REST in the Digital-SNOWTAM Trial Why it is used Architecture How it is used Example

3. Digital-SNOWTAM Trial Introduction

4. AIXM XML Developers' Seminar 4 Demo

5. REST Introduction

6. AIXM XML Developers' Seminar 6 REST Representational State Transfer An architectural style

7. AIXM XML Developers' Seminar 7 Main definitions Resources Representations Actions – Verbs Type of data

8. AIXM XML Developers' Seminar 8 Resources A resource is a real thing that can be acted upon with a request Anything that can be named can be a resource e.g. PDF, XML, SVG, HTML page, today’s weather report. They are found using URIs (see www.purl.org)

9. AIXM XML Developers' Seminar 9 Resources and time Resources can vary over time. The only thing that must be static is the semantic of the mapping (name).

10. AIXM XML Developers' Seminar 10 Representations The data transmitted to and from the resource is called a representation Captures the current or intended state of the resource It can be a copy of the file or a description of it

11. AIXM XML Developers' Seminar 11 Transparency How the representation is found should be transparent to the user It could involve the server parsing the URL, constructing a database query and returning the result

12. AIXM XML Developers' Seminar 12 Actions - Verbs Once the representation of the resource has been returned, an action can be performed The interaction is determined by the HTTP verbs: GET, PUT, POST and DELETE The interaction is stateless

13. AIXM XML Developers' Seminar 13 Type of data When performing an action on a resource it is important to know what the resource is MIME types can help here (e.g. text/xml) The format of the request/response can be specified in a schema

14. AIXM XML Developers' Seminar 14 Actions GET Used to read a resource or as a query Should be side-effect free PUT Replaces the target resource in its entirety DELETE Removes the resource POST Has a variety of meanings e.g. it can be used when only a subset of a resource has to be modified

15. REST in the Digital- SNOWTAM Trial

16. AIXM XML Developers' Seminar 16 Why it is used Support the provision of AIXM 5.1 data to end-user applications The REST interface shall enable digital users to: Query the Digital SNOWTAM database for the list of airports contained in the database and select one of these airports; Get the list of airport’s features for a selected airport; Get the surface contamination records for each such feature; Get the feature related through xlink:href; Get the SNOWTAM text and the free text translation associated with an Airport.

17. AIXM XML Developers' Seminar 17 Architecture The REST implementation framework used is Struts 2 REST plug- in which in turn uses the Convention plug-in. See http://struts.apache.org/2.x/docs/rest-plugin.html for more information.http://struts.apache.org/2.x/docs/rest-plugin.html Please note the REST plug-in is only available for Struts 2.1.1 or above.

18. AIXM XML Developers' Seminar 18 Implementation Only GET is need for the trial.

19. AIXM XML Developers' Seminar 19 Workflow In order to interrogate the database: request the list of airports select one airport and use the xlink:href to get the details about this airport select a runway and use the corresponding xlink:href to get the details about this feature The xlink:href is a URL compliant to the Digital SNOWTAM REST request structure

20. AIXM XML Developers' Seminar 20 Base URL Base: http:// / E.g. http://l-accept-04.pulsar.be/ec-xsnowtam-rest-accepthttp://l-accept-04.pulsar.be/ec-xsnowtam-rest-accept Then add a Suffix: /

21. AIXM XML Developers' Seminar 21 Find Airports Suffix: /airportheliports[?designator= ] There are about 15000 airports/heliports in the database so… Optional Parameter: The pattern is of the form [A-Z*]{1,4} where * is the wildcard character. Pattern samples: EB* matches any designator beginning with EB *BBR matches any designator ending in BBR E*R matches any designator beginning with E and ending with R

22. AIXM XML Developers' Seminar 22 Query an Airport Suffix: /airportheliports/ [?features=yes/no&conta minations=yes/no&date= ] Mandatory parameter: gml:identifier – UUID Optional parameters: date - is the search date&time features - specify if xlink:href pointing to related features must be included in the results, e.g. runways, taxiways, etc contaminations - specify if contaminations must be included or not in the result

23. Examples

24. AIXM XML Developers' Seminar 24 1 – Create Contamination Use Bromma to create a contamination

25. AIXM XML Developers' Seminar 25 2 – Use REST to find the airport http://l-accept-04.pulsar.be/ec-xsnowtam-rest- accept/airportheliports?designator=ESSBhttp://l-accept-04.pulsar.be/ec-xsnowtam-rest- accept/airportheliports?designator=ESSB

26. AIXM XML Developers' Seminar 26 3 – Find SNOWTAM Text http://l-accept-04.pulsar.be/ec-xsnowtam-rest- accept/airportheliports/77a0de0e-277a-4824-a561- 2ba779a3658c?features=yes&contaminations=yeshttp://l-accept-04.pulsar.be/ec-xsnowtam-rest- accept/airportheliports/77a0de0e-277a-4824-a561- 2ba779a3658c?features=yes&contaminations=yes snowtam-icao SW** ESSB 10090900 (SNOWTAM A)ESSB B)10090900 C)12 F)3/2/2 G)1/1/1 H)2/3/3 BRD )

27. AIXM XML Developers' Seminar 27 4 – Get Airport data http://l-accept-04.pulsar.be/ec-xsnowtam-rest- accept/airportheliports/77a0de0e-277a-4824-a561- 2ba779a3658c?features=yeshttp://l-accept-04.pulsar.be/ec-xsnowtam-rest- accept/airportheliports/77a0de0e-277a-4824-a561- 2ba779a3658c?features=yes … …

28. AIXM XML Developers' Seminar 28 5- Get Runway contamination http://l-accept-04.pulsar.be/ec-xsnowtam-rest- accept/runways/58ea128d-1bbe-47f6-92fe- a8961b4bf5ee?contaminations=yeshttp://l-accept-04.pulsar.be/ec-xsnowtam-rest- accept/runways/58ea128d-1bbe-47f6-92fe- a8961b4bf5ee?contaminations=yes 2009-10- 09T09:00:00Z 1 MEDIUM BRD NO 1 WATER 2_THIRD

29. AIXM XML Developers' Seminar 29 6 - Time based http://l-accept-04.pulsar.be/ec-xsnowtam-rest- accept/runways/58ea128d-1bbe-47f6-92fe- a8961b4bf5ee?date=9/10/2009%2009:00&contaminations=yes

30. AIXM XML Developers' Seminar 30 AIXM 5.1 TEMPDELTA and a BASELINE