The GML geometry format supports similar geometries to the ones supported by the GeoRSS simple geometry format. Arcs, paths and curves will be downgraded to line geometry. Similarly, areas and ellipses will also be downgraded to polygon geometry. For example, a feature with donut geometry will have it’s geometry written out as a polygon, and the interior of the donut will be ignored. When writing in the format, the GeoRSS writer will attempt to downgrade more complex geometries to one of these types. The GeoRSS Simple geometry format supports point, line, polygon geometry. If a feature with any other type of geometry is passed to the GeoRSS writer while it is writing in this format, the feature’s geometry will be ignored. The W3C Geo geometry format only supports point geometry. Since the GeoRSS specification does not allow multi-geometries, the GeoRSS writer will always only attempt to write the first item of an aggregate of multi-geometry. The GeoRSS writer will attempt to downgrade unsupported geometry to a supported type, but this is not always possible. The three different geometry formats support varying levels of geometry complexity. This ensures that the GeoRSS writer always tries to produce a valid Atom or RSS feed, regardless of the features that are passed to it. Furthermore, if a feature has no value for certain attributes, the GeoRSS writer will provide default values for these attributes. Any feature attributes which are not contained in the GeoRSS feature schema will be ignored. This means that the writer will look at features for the attributes specified by the GeoRSS schema. Any feature whose type is not ‘Feed’ will be treated as an ‘Entry’ type feature. If no feature is specified to be a Feed type feature, then the writer will use default values for the metadata it produces. The GeoRSS writer can write any collection of features out as a GeoRSS feed. If the XML element contains XML attributes or non-text child elements, then the entire XML element will be the value of the new attribute. If the XML element has no attributes and only text content, the value of the new feature attribute will be the text content of the XML element. If the element has no prefix, the new attribute name will be _name. If the xml element has a prefix, the new attribute will be named prefix_name. The new attribute will be named based on the prefix and name of the unknown element. If the reader encounters XML that it cannot use to populate the predefined GeoRSS feature schema, it will simply add the XML to the feature as a new attribute. The GeoRSS reader will not ignore any XML elements that it encounters. The reader can access these URL’s directly, or it can be routed through a proxy server. The reader can handle an XML feed from a local or network file, or a remote URL accessible via http or ftp. Because each feed format has a similar structure, the same schema is used for every feed that the reader processes, regardless of the feed format and version. A single FME feature is created for the feed metadata, and a FME feature is created for each entry in the feed. The GeoRSS reader works by mapping an XML feed and its entries into FME features. Specifications for each of these methods can be found at. The GeoRSS reader and writer both support each of the three methods used to include spatial information: W3C Geo, GeoRSS Simple, and GML. The GeoRSS specification defines a way to add spatial information to an XML feed. The GeoRSS writer can output feeds in RSS 2.0 or Atom 1.0. The specifications for the current versions of these formats can be found at and, respectively.Ĭurrently the GeoRSS reader supports RSS versions 0.91, 0.92 and 2.0, as well as Atom 0.3 and 1.0. Both of these formats have a similar structure in that the feed contains metadata and a collection of entries. OverviewĪn XML feed can be in one of several different formats, with the most common formats being RSS and Atom. The GeoRSS reader/writer plug-in enables FME to read and write XML feeds and their spatial data extensions. Using GeoRSS, an XML feed can be extended to include spatial data. XML feeds are a popular method of publishing information to a set of subscribers. Licensing options for this format begin with FME Professional Edition.
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