The document header provides information to identify the contents of a data payload. It was developed to further automate the data exchange process so that data can be more readily identified during transport and at its processing destination. Currently, the NEI dataflow supports use of the header, but the generic header format can be extended by modifying or adding elements for use with other data flows.
The document header can describe what a data payload contains, who submitted it and when, as well as instructions on processing payload contents, such as whether the contents are additions, deletions, or updates. The header is independent of payload contents, so no data schema changes are necessary, and header usage by Network Nodes is optional-pass through can be employed.
Table 3.2. Common Network Exchange Header Fields:
| Header Element | Description | Format | Possible Values | Required | Example Value |
|---|---|---|---|---|---|
| Author | First and last name of individual generating XML file(s) | string | Any | Yes | John Doe |
| Organization | Name of Company or Environmental Agency of individual generating XML file(s) | string | Any | Yes | Provide name of the organization submitting the dataset |
| Title | Type of Submission | string | Any (e.g. Source type = Point, Nonpoint stationary, NonRoad Mobile, OnRoad Mobile, or Biogenic) | Yes | Biogenic |
| CreationTime | Time when the document is generated | dateTime | Date and time value | Yes | 2003-12-12T12:12:12.0000000-05:00 |
| Comment | Open text for submitter comments | string | Any | No | NEI submission |
| DataService | Name of a service request | string | Any | No | SubmitNEIByDate |
| ContactInfo | Street address, City, State, Zip code, Area code and telephone number, Email address | string | Any | No | 8400 Corporate Dr., Lanham, MD, 20784, 301-555-5555, someone@somewhere.com |
| Notification | A URI where result/report can be sent | anyURI | URI value | No | email@domain.com |
| Sensitivity | Level of document sensitivity | string | Unclassified, Confidential, Secret, TopSecret | No | Unclassified |
| Property | Other properties of the document (use name value pairs) | string/string | Any/Any | No | See table below |
| Operation (Payload attribute) | Operation to be performed (submission status) | string | Add, Update, Delete, Refresh, Unspecified | Yes | Refresh |
Note that any number of Notification elements can be specified in a single XML instance document.
Table 3.3. Proposed NEI-specific fields (Inserted using the Property tag elements):
| Header Element | Description | Format | Possible Values | Required | Example Value |
|---|---|---|---|---|---|
| GeographicCoverage | Representative geographic area for the data submitted | string | Any (e.g., Statewide, Nonattainment area, or Other) | Yes | Statewide |
| PollutantCoverage | PollutantCode(s) included in file(s) | string | VOC; NOx; CO; SO2; PM10; PM2.5; NH3; HAPs | Yes | VOC; NOx; CO; SO2; PM2.5; NH3 |
| InventoryYear | Year of inventory data in data set | string | Submission year (YYYY) | Yes | 2002 data for the 2004 reporting year |
Generic Header Elements
Optional Header Elements
You can either design your own header using an XML generator, or take advantage of the free toolkit offered by the Exchange Network in .NET or Java versions. The toolkits can be downloaded from the following links:
.NET V0.9 (Beta):
https://test.epacdxnode.net/CDX_HEADER_NET_CSHARP_TEST_V09.zip
Java V0.9 (Beta):
https://test.epacdxnode.net/CDX_HEADER_V09.zip
Toolkit Source code:
.NET V0.9 (Beta): https://test.epacdxnode.net/CDX_HEADER_NET_CSHARP_SRC.zip
Header Schema:
Network Exchange Document schema V0.9 (Beta):
https://test.epacdxnode.net/ExchangeNetworkDocument.xsd
An XML snippet for composing your own header is provided Here
A sample NEI Header Document can be found Here