IWXXM Validation Web Service

IWXXM Validation Web Service is a JSON-RPC 2.0 web service which allows to validate IWXXM data against XSD schemas and Schematron rules stored in the local filesystem with XML catalogue. The validation code originated from NCAR CRUX.

You can run the application as JSON-RPC web service or as a command line tool to validate provided files.

There is a demo web site which uses this validator running on https://iwxxm.iblsoft.com/iwxxm. At the moment the site is protected with a login/password, to request access please write an e-mail to iwxxm-support@iblsoft.com. We are open to cooperation with other organisations and companies working on IWXXM implementation to increase interoperability across packages coming from different vendors. The features of the demo site are:

1. Validation with IWXXM 2.1, 2.0, 2.0-RC1, 1.1, 1.0 schemas
2. Conversion from TAC METAR, SPECI, SIGMET, AIRMET, VA Advisory to IWXXM 2.0 and 1.1
3. Conversion back from IWXXM to TAC (with some limitations)

Requirements

Requires JDK 1.7 or higher. To build application, Maven 3.2.3 is required.

Building the application

To build application use Maven 3.2.3 or later. Go to the directory with pom.xml file and type following command:

mvn clean install 

Running as a json-rpc web service

On Linux machine, it is possible to start json-rpc service by command

./iwxxm.sh --service

On Windows machine, it is possible to start json-rpc service by command

iwxxm.cmd --service

By default, service is running by default on the port 8040, on the url http://<server-name>:8040/json-rpc.

Input request:

• requestVersion: version of message request, now must be set to "1.0".
• iwxxmVersion: IWXXM version which will be used for validation, if omitted, than version is detected from provided IWXXM data
• iwxxmData: content of validated IWXXM XML report or report collection

{
 "jsonrpc": "2.0",
 "id": "iwxxm1",
 "method": "validate",
 "params": {
    "request": {
        "requestVersion": "1.0",
        "iwxxmData": "<content of validates IWXXM XML message>"
    }
  }
}

Output response:

• responseVersion: version of response message, now always 1.0
• valid: true or false, indicates if validated message is valid or not
• validationErrors: list of validation errors if report or report collection is not valid. If provided iwxxm data are valid, than this property is omitted

Example of response for valid IWXXM data:

{
  "jsonrpc": "2.0",
  "id": "iwxxm1",
  "result": {
    "responseVersion": "1.0",
    "valid": true
  }
}

Example of response for invalid IWXXM data:

{
  "jsonrpc": "2.0",
  "id": "iwxxm1",
  "result": {
    "validationErrors": [
    {
      "errorMessage": "cvc-complex-type.4: Attribute 'permissibleUsage' must appear on element 'iwxxm:SIGMET'.",
      "lineNumber": 1,
      "columnNumber": 1108
     },
    {
      "errorMessage": "cvc-complex-type.4: Attribute 'uom' must appear on element 'iwxxm:directionOfMotion'.",
      "lineNumber": 1,
      "columnNumber": 4399
     },
     {
       "errorMessage": "SIGMET.EMC1: directionOfMotion shall be reported in degrees (deg). ((if(exists(iwxxm:directionOfMotion) and (not(exists(iwxxm:directionOfMotion/@xsi:nil)) or iwxxm:directionOfMotion/@xsi:nil != 'true')) then (iwxxm:directionOfMotion/@uom = 'deg') else true()))"
     }
   ],
   "responseVersion": "1.0",
   "valid": false
  }
}

Validation of multiple IWXXM messages in one HTTP request

It is possible to validate multiple IWXXM messages in one HTTP request. JSON-RPC batching can be used for this purpose - add multiple JSON-RPC request in array and send it to the web service.

Example of batch request:

[
  {
    "jsonrpc": "2.0",
    "id": "iwxxm1",
    "method": "validate",
    "params": { 
      "request": {
        "requestVersion": "1.0",
        "iwxxmData": "<content of validates IWXXM XML message>"
      }
    }
  },
  {
    "jsonrpc": "2.0",
    "id": "iwxxm2",
    "method": "validate",
    "params": { 
      "request": {
        "requestVersion": "1.0",
        "iwxxmData": "<content of validates IWXXM XML message>"
      }
    }
  }
]

Example of batch response:

[
  {
    "jsonrpc": "2.0",
    "id": "iwxxm1",
    "result": {
      "responseVersion": "1.0",
      "valid": true
    }
  },
  {
    "jsonrpc": "2.0",
    "id": "iwxxm2",
    "result": {
      "responseVersion": "1.0",
      "valid": true
    }
  }
]

Running validation from command line

It is possible to validate IWXXM reports stored in local files by following command:

./iwxxm.sh --validate file1.xml file2.xml file_with_wildcars.xml

or on Windows machine:

iwxxm.cmd --validate file1.xml file2.xml file_with_wildcars.xml

Updating XML Schema catalog

To prevent download of XSD schemas from the network, XML Schema catalog is stored on the local disk in the directory config/schemas. Content of XML schema catalog (together with schematron rules) is extracted from ZIP file downloaded from http://schemas.wmo.int/iwxxm/2.1/zip/iwxxm-schema-bundle-2.1.zip.

Note: in the IWXXM version 2.0, there is a problem with original iwxxm-collect.sch file - it uses sch:include elements to include iwxxm.sch and collect.sch from iwxxm 1.2. Using of sch:include is not supported by schematron validation rules. Our validator runs schematron validation against every .sch file placed in the rule directory (for appropriate version of iwxxm). As a workaround for problem with includes, original iwxxm-collect.sch file was renamed to iwxxm-collect.sch.txt and collect.sch file from 1.2 IWXXM schematron rules was copied also into 2.0 rule directory.

Configuration of web service

Default web service configuration can be changed in the file config/iwxxm-webservice-config.properties. Location of this configuration file can be changed by setting JVM property -DconfigDir=<path_to_directory_with_config_file>.