context.xsd 2008/03/10 This XML Schema defines the encoding of an OWS Context Document. Primary editor: Tom Kralidis. Copyright (c) 2007 OpenGIS, All Rights Reserved. A Context document contains one map defined within a ResourceList. This element describes the list of all resources to build a required application view. The Layer/FeatureType/Coverage elements are presented in a bottom to top approach. Each Resource is defined in a Layer OR FeatureType OR Coverage element in the Context document XML. If desired, Resources may be repeated with different attributes (e.g. different styles). The root element of the Context, this element must contain the version number of the Context Specification which the current Context document complies with. This element is composed of two elements, one for general information and another defining a list of resources. An element "General" that contains layer-independent information about the current Context document such as the bounding box and the spatial reference system and also some information describing the Context document itself such as title, abstract, etc. This element is required. The version of the specification. Fixed value of 'x.y.z'. An identifier for the document. This identifier may further be used to identify the document in catalogs. An element "Window" presenting the size in pixels of the map the Context document describes. Negotiation between Context defined aspect ratio and typical client aspect ratio (according to the client’s vendor) is left to the client. This element is optional. A reference to an image that might be attached to the Context document. It can be, for instance, the logo of the project for which the context has been setup, or an overview of the map the context describes. This element contains a link to the image as well as the dimension of the image (in pixels) and its format. This element is optional. A URL reference to a webpage which contains relevant information to the view. This element is optional. The Extension element is a container tag in which arbitrary vendor specific information can be included without compromising the ability of other clients to enforce schema validation. This tag should not be used to introduce new candidate elements that are intended to promote interoperability. Content in an <Extension> element should not be expected to be preserved in transfers of Context documents between different systems. The width of the Window. In dimensions pixels. The height of the Window, in dimensions pixels Connect point URL prefix for the HTTP request method for this operation request. The xlink:href attribute in the xlink:simpleLink attribute group shall be used to contain this URL prefix. The other attributes in the xlink:simpleLink attribute group should not be used The Layer element must enclose one or more child elements providing information about the Layer. The meaning of these elements is defined hereunder. Maximum features that should be used to query the layer. A FeatureType can potentially contain a very large dataset that is impractical to download to a client, and/or too large for a client's renderer. A GML FeatureCollection provided inline within the document. The Extension element is a container tag in which arbitrary vendor specific information can be included without compromising the ability of other clients to enforce schema validation. This tag should not be used to introduce new candidate elements that are intended to promote interoperability. Content in an <Extension> element should not be expected to be preserved in transfers of Context documents between different systems. queryable : contains true if the layer is set queryable (required for a WMS layer)" The element defining the service from which the named Layer may be requested This element contains a link to an online resource where data corresponding to the layer can be found. This element is optional. This element contains a link to an online resource where descriptive metadata corresponding to the layer can be found. This element is optional. The parent element containing the list of available styles for this layer. Each style is defined in a Style element. A StyleList shall include at least one Style element. The Extension element is a container tag in which arbitrary vendor specific information can be included without compromising the ability of other clients to enforce schema validation. This tag should not be used to introduce new candidate elements that are intended to promote interoperability. Content in an <Extension> element should not be expected to be preserved in transfers of Context documents between different systems. An human-readable identifier for the object. An identifier for the document. This identifier may further be used to identify the document in catalogs. group: name which enables a viewer client generator to group in providing grouped themes of layers/feature types/coverages hidden : contains true if the layer should be hidden in the client result map (required) opacity:0: map data represents vector features that probably do not completely fill space. 1: map data are mostly or completely opaque. Online Resource element: the link to the online resource (required) Whether this is the default binding endpoint for this resource. Resources may have multiple bindings (for example, as a means to associate a WMS and WFS) Service : the type of the service according to OGC interfaces, such as WMS, WFS. (required) Version : Version number of the OGC interface specification which corresponds to the service (required) Title : the title of the service (extracted from the Capabilities by the Context document creator) (optional)" Describe one output image format for the resource. current : contains 1 if the current image format is selected." A Style element may be composed in two different ways: named style or SLD. The name of the style (extracted from Capabilities by the Context document creator). This element is required. The human-readable title of the style (extracted from Capabilities by the Context document creator). This element is required. A narrative description of the current style (extracted from Capabilities by the Context document creator). This element is optional. The location of an image of a map legend describing the current style (extracted from Capabilities by the Context document creator). This element is optional. Each Style element may alternatively define the style(s) of the layer with a SLD element. The SLD element must contain required Name and optional Title elements which identify the particular element of a Styled Layer Descriptor to be used for this style. Name of the Style Title of the Style HTTP URL of a legend icon idicative of the Style HTTP URL of SLD document Provides the name of the HTTP method to be performed on this resource (either GET or POST). Note: we should use OWS Common for this This allows additional elements to be added to support special parameters which are not supported by this schema. This allows additional elements to be added to support non WMS Layer services.