1. Spatial Map Visualization Developer's Guide
  2. Map Visualization Servers
  3. Map Visualization Component Map Data Server

3.1 Map Visualization Component Map Data Server

The map visualization component map data server provides services for streaming live data from a database server to a client.

The data can be consumed by the Oracle Maps JavaScript API client, or be edited by the API editing utilities. It is also used as the middle-tier component for handling data synchronization tasks.

At the most basic level, a client sends a request to the map data server, specifying the name of a theme and an optional bounding box. The server then returns the live data (including both geometries and attributes) in compressed GeoJSON format.

Parent topic: Map Visualization Servers

3.1.1 Domains and Map Data Server URL Patterns

The map data server uses domains, where each domain corresponds to a map visualization component data source. For example, to request data from the mvdemo data source, the URL must have the following pattern:

http://example.com:8080/mapviewer/dataserver/mvdemo?

In this URL request, /dataserver refers to the map data server. /mvdemo is the path information, which indicates which domain or data source this request is directed against. There is no need to specify the data source explicitly in the rest of the URL request. This URL pattern provides flexibility in terms of protection. A user or a web administrator can easily set up different levels of protection for different domains using such a URL pattern.

To get a quick help regarding the full list of supported HTTP request parameters, you can issue a request that includes the help parameter. For example:

http://example:8080/mapviewer/dataserver/mvdemo?help=true

This example returns a list of supported parameters. (Note that the /mvdemo path is still required even for this help request.)

Parent topic: Map Visualization Component Map Data Server

3.1.2 Map Data Server Request Parameters

In a map data server request to get data, the URL must include appropriate query parameters. The data could be from a map visualization component predefined geometry theme or JDBC theme.

Parent topic: Map Visualization Component Map Data Server

3.1.2.1 Getting Data from a Predefined Geometry Theme

Before getting data from a predefined geometry theme, be sure that the predefined geometry theme is properly defined. If it is not properly defined, modify its definition or create a new predefined geometry theme with the proper definition.

Besides the geometry column of a spatial table, if you also need some attribute columns for an application, then your geometry theme's STYLING_RULES column must have the <hidden_info> element for defining needed attributes. For example, if your application needs a geometry theme (such as CUSTOMERS) to represent a spatial table, and if you also need each customer's name, city, and sales amount, then the STYLING_RULES should look similar to the following: 

SQL> select STYLING_RULES from user_sdo_themes where name='CUSTOMERS';
 
STYLING_RULES
--------------------------------------------------------------------------------
<?xml version="1.0" standalone="yes"?>
<styling_rules>
  <hidden_info>
    <field column="name" name="Name"/>
    <field column="city" name="City"/>
    <field column="sales" name="Sales"/>
  </hidden_info>
  <rule>
    <features style="M.STOPLIGHT_RED"> </features>
  </rule>
</styling_rules>

The Map Builder utility is the recommended tool for modifying or creating geometry themes.

For information using styling rules in a predefined geometry theme, see Styling Rules in Predefined Spatial Geometry Themes.

The following parameters are available for a map data server request to get data from a map visualization component predefined geometry theme. The t (theme name) parameter is required; the others are optional.

  • t: Name of the theme.

  • bbox: Bounding box. Must be a comma-delimited list of minx,miny,maxx,maxy.

  • to_srid: SRID (spatial reference system) in which to return the data.

  • bbox_srid: SRID (spatial reference system) of the bounding box, if different from the native SRID of the data.

  • seq: Sequence ID, to be used when getting data in multipart format.

  • dadp: Digits after decimal point: the maximum number of digits after the decimal point for the coordinates in the returned data.

  • include_style_info: Determines whether styling information (rendering/labeling style name and related columns) should be included with each feature. (The default is true.)

  • include_label_box: Determines whether a label box should be included with each polygon feature. (The default is true.) A label box is a near maximum rectangle inside the polygon. A label placed inside this rectangle is guaranteed to be completely inside the polygon feature. This parameter is ignored for non-polygon features.

  • simplify: Determines whether geometries will be simplified. (The default is false.)

  • threshold: If simplify is true, then threshold controls the approximate percentage of vertices from the input geometry to be eliminated during the simplification. (Must be a number between 1 and 99.) For example, if the value is 10, then relatively few (approximately 10%) of the vertices will be eliminated and most (approximately 90%) will be kept; but if the value is 90, then approximately 90% of the vertices will be eliminated (and only approximately 10% will be kept).

The following are some examples.

To get all the data from the CITIES table in the 3857 SRID:

http://example:8080/mapviewer/dataserver/mvdemo?t=theme_demo_cities&to_srid=3857

To get all the data from the CITIES table that interacts with a specified bbox in 3857 SRID:

http://example:8080/mapviewer/dataserver/mvdemo?t=theme_demo_cities&bbox=-122.0,25,-100,45&to_srid=3857

To get all the data from the CITIES table that interacts with a specified bbox in 3857 SRID, with 3 digits after the decimal points, and without styling information:

http://example:8080/mapviewer/dataserver/mvdemo?t=theme_demo_cities&bbox=-122.0,25,-100,45&to_srid=3857&dadp=3&include_style_info=no

To get all data from the COUNTIES table and include label boxes:

http://example:8080/mapviewer/dataserver/mvdemo?t=theme_demo_counties&include_label_box=yes

Parent topic: Map Data Server Request Parameters

3.1.2.2 Getting Data from a JDBC Theme

The following parameters are available for a map data server request to get data from a map visualization component theme based on a dynamic JDBC theme. The t (theme name) and sql (SQL query) parameters are required; the others are optional.

  • t: Name of the theme.

  • sql: The complete SQL query, properly URL encoded.

  • asis: Determines whether the query should be executed "as is". The default is false, which causes the map visualization component to embed the SQL query as a subquery of its spatial filter query. If the value is true, the map visualization component does not attempt to modify the supplied query string.

  • bbox: Bounding box. Must be a comma-delimited list of minx,miny,maxx,maxy.

  • to_srid: SRID (spatial reference system) in which to return the data.

  • bbox_srid: SRID (spatial reference system) of the bounding box, if different from the native SRID of the data.

  • seq: Sequence ID, to be used when getting data in multipart format.

  • dadp: Digits after decimal point: the maximum number of digits after the decimal point for the coordinates in the returned data.

  • include_style_info: Determines whether styling information (rendering/labeling style name and related columns) should be included with each feature. (The default is true.)

  • include_label_box: Determines whether a label box should be included with each polygon feature. (The default is true.) A label box is a near maximum rectangle inside the polygon. A label placed inside this rectangle is guaranteed to be completely inside the polygon feature. This parameter is ignored for non-polygon features.

The following are some examples.

To get all the data of the CITIES table in SRID 3857:

http://example:8080/mapviewer/dataserver/mvdemo?t=theme1&sql=select+*+from+cities&to_srid=3857

To get all the data of the table CITIES within a given bbox in SRID 3857:

http://example:8080/mapviewer/dataserver/mvdemo?t=theme1&sql=select+*+from+cities&to_srid=3857&bbox=-122.0,25,-100,45

To run the query as is, without a bbox and return data in SRID 3857:

http://example:8080/mapviewer/dataserver/mvdemo?t=theme1&sql=select+*+from+cities&to_srid=3857&bbox=-122.0,25,-100,45&asis=t

Parent topic: Map Data Server Request Parameters

3.1.2.3 Getting Annotation Text from a JDBC Theme

A request to retrieve annotation text elements from a JDBC theme is similar to that in Getting Data from a JDBC Theme

The following parameters are available for a map data server request to get data from a map visualization component theme based on a dynamic JDBC theme. The t (theme name), sql (SQL query, geom_type, and base_table parameters are required; the others are optional.

  • t: Name of the theme.

  • sql: The complete SQL query, properly URL encoded.

  • geom_type: Must be specified as annotation to indicate that the spatial column is on annotation type.

  • base_table: The database table (for the server to read annotation text metadata information for that table).

  • asis: Determines whether the query should be executed "as is". The default is false, which causes the map visualization component to embed the SQL query as a subquery of its spatial filter query. If the value is true, the map visualization component does not attempt to modify the supplied query string.

  • bbox: Bounding box. Must be a comma-delimited list of minx,miny,maxx,maxy.

  • to_srid: SRID (spatial reference system) in which to return the data.

  • bbox_srid: SRID (spatial reference system) of the bounding box, if different from the native SRID of the data.

  • seq: Sequence ID, to be used when getting data in multipart format.

  • dadp: Digits after decimal point: the maximum number of digits after the decimal point for the coordinates in the returned data.

  • include_style_info: Determines whether styling information (rendering/labeling style name and related columns) should be included with each feature. (The default is true.)

  • include_label_box: Determines whether a label box should be included with each polygon feature. (The default is true.) A label box is a near maximum rectangle inside the polygon. A label placed inside this rectangle is guaranteed to be completely inside the polygon feature. This parameter is ignored for non-polygon features.

The following example retrieves annotation text information:

http://example:8080/mapviewer/dataserver/tilsmenv?t=theme1&sql=select+*+from+annotext_table&geom_col=textobj&geom_type=annotation&base_table=annotext_table&bbox=0,0,10,10

A typical response includes the annotation text table metadata information plus the annotation text feature. Each annotation text feature can have one or more text elements. Each text element can be defined by a text value, a location, a leader line, and graphic attributes. Refer to OGC specification of annotation texts for additional information.

The response looks like the following:

{"type":"AnnotationText",
"collectionName":"theme1",
"srs":0,
"geodetic":false,
"bbox":[0, 0, 10, 10],
"attr_names":["ID"],
"attr_types":["double"],
"default_text_attributes":{"fontWeight":"Normal","fontStyle":"Normal","textDecoration":"None","letterSpacing":"Normal","wordSpacing":"Normal","fill":"black","fill-opacity":1.0,"stroke":"black","strokeWidth":1.0,"stroke-opacity":1.0,"horizontalAlignment":"start","verticalAlignment":"top","multilineJustification":"left","multilineSpacing":0.0},
"metadata":{"textExpression":"name","textAttributes":{"fontFamily":"Serif","fontSize":14.0,"fill":"#ff0000"}},
"features":[
{"type":"AnnoText", "elements":[{"location":{"type":"Point", "coordinates":[1, 1]},"textValue":"Sample Label 1","leaderLine":{"type":"LineString", "coordinates":[0,0,1,1]}}],"envelope":{"type":"Rectangle", "coordinates":[0,0,1,1]},"properties":{"ID":"1.0"}},
{"type":"AnnoText", "elements":[{"location":{"type":"LineString", "coordinates":[2,5,4,5,6,5]},"leaderLine":{"type":"LineString", "coordinates":[4,3,4,5]},"textAttributes":{"fontFamily":"Dialog","fontSize":14.0,"fill":"blue"}}],"envelope":{"type":"Rectangle", "coordinates":[2,3,6,5]},"properties":{"ID":"3.0"}},
{"type":"AnnoText", "elements":[{"location":{"type":"Point", "coordinates":[10, 10]},"textValue":"Sample Label 2","leaderLine":{"type":"LineString", "coordinates":[5,10,10,10]}}],"envelope":{"type":"LineString", "coordinates":[5,10,10,10]},"properties":{"ID":"2.0"}}
]}

Parent topic: Map Data Server Request Parameters

3.1.2.4 Getting Topology Data

A topology set is defined by a set of topology primitives (faces, edges, and nodes(. Each topology feature can be associated with one or more topology primitives.

A request to retrieve the topology primitives must contain the topology parameter, as in the following example:

http://example:8080/mapviewer/dataserver/tilsmenv?topology=city_data&bbox=10,10,35,35

The response includes all primitives that interact with input MBR:

{"type":"TopologyPrimitives",
"topology":"city_data",
"srs":0,
"bbox":[0, 0, 62, 42],
"face_attr_names":["FACE_ID","BOUNDARY_EDGE_ID","ISLAND_EDGE_ID_LIST","ISLAND_NODE_ID_LIST"],
"face_attr_types":["integer","integer","array:integer","array:integer"],
"edge_attr_names":["EDGE_ID","START_NODE_ID","END_NODE_ID","NEXT_LEFT_EDGE_ID","PREV_LEFT_EDGE_ID","NEXT_RIGHT_EDGE_ID","PREV_RIGHT_EDGE_ID","LEFT_FACE_ID","RIGHT_FACE_ID"],
"edge_attr_types":["integer","integer","integer","integer","integer","integer","integer","integer","integer"],
"node_attr_names":["NODE_ID","EDGE_ID","FACE_ID"],
"node_attr_types":["integer","integer","integer"],
"primitives":[
{"type":"Face", "mbr_geometry":{"type":"Rectangle", "coordinates":[3,30,15,38]}, "properties":{"FACE_ID":"1", "BOUNDARY_EDGE_ID":"1", "ISLAND_EDGE_ID_LIST":[25]}},
{"type":"Face", "mbr_geometry":{"type":"Rectangle", "coordinates":[9,14,21,22]}, "properties":{"FACE_ID":"3", "BOUNDARY_EDGE_ID":"19"}},
{"type":"Face", "mbr_geometry":{"type":"Rectangle", "coordinates":[9,6,21,14]}, "properties":{"FACE_ID":"6", "BOUNDARY_EDGE_ID":"20"}},
{"type":"Face", "mbr_geometry":{"type":"Rectangle", "coordinates":[17,30,31,40]}, "properties":{"FACE_ID":"2", "BOUNDARY_EDGE_ID":"2", "ISLAND_NODE_ID_LIST":[4]}},
{"type":"Face", "mbr_geometry":{"type":"Rectangle", "coordinates":[21,6,35,14]}, "properties":{"FACE_ID":"7", "BOUNDARY_EDGE_ID":"10"}},
{"type":"Face", "mbr_geometry":{"type":"Rectangle", "coordinates":[21,14,35,22]}, "properties":{"FACE_ID":"4", "BOUNDARY_EDGE_ID":"17"}},
{"type":"Face", "mbr_geometry":{"type":"Rectangle", "coordinates":[35,14,47,22]}, "properties":{"FACE_ID":"5", "BOUNDARY_EDGE_ID":"15"}},
{"type":"Face", "mbr_geometry":{"type":"Rectangle", "coordinates":[35,6,47,14]}, "properties":{"FACE_ID":"8", "BOUNDARY_EDGE_ID":"16"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[8,30,16,30,16,38,3,38,3,30,8,30]}, "properties":{"EDGE_ID":"1", "START_NODE_ID":"1", "END_NODE_ID":"1", "NEXT_LEFT_EDGE_ID":"1", "PREV_LEFT_EDGE_ID":"1", "NEXT_RIGHT_EDGE_ID":"-1", "PREV_RIGHT_EDGE_ID":"-1", "LEFT_FACE_ID":"1", "RIGHT_FACE_ID":"-1"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[4,31,7,31,7,34,4,34,4,31]}, "properties":{"EDGE_ID":"26", "START_NODE_ID":"20", "END_NODE_ID":"20", "NEXT_LEFT_EDGE_ID":"26", "PREV_LEFT_EDGE_ID":"26", "NEXT_RIGHT_EDGE_ID":"-26", "PREV_RIGHT_EDGE_ID":"-26", "LEFT_FACE_ID":"9", "RIGHT_FACE_ID":"1"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[9,22,21,22]}, "properties":{"EDGE_ID":"6", "START_NODE_ID":"16", "END_NODE_ID":"17", "NEXT_LEFT_EDGE_ID":"7", "PREV_LEFT_EDGE_ID":"21", "NEXT_RIGHT_EDGE_ID":"-21", "PREV_RIGHT_EDGE_ID":"19", "LEFT_FACE_ID":"-1", "RIGHT_FACE_ID":"3"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[9,14,9,22]}, "properties":{"EDGE_ID":"21", "START_NODE_ID":"15", "END_NODE_ID":"16", "NEXT_LEFT_EDGE_ID":"6", "PREV_LEFT_EDGE_ID":"22", "NEXT_RIGHT_EDGE_ID":"9", "PREV_RIGHT_EDGE_ID":"-6", "LEFT_FACE_ID":"-1", "RIGHT_FACE_ID":"3"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[9,14,21,14]}, "properties":{"EDGE_ID":"9", "START_NODE_ID":"15", "END_NODE_ID":"14", "NEXT_LEFT_EDGE_ID":"19", "PREV_LEFT_EDGE_ID":"-21", "NEXT_RIGHT_EDGE_ID":"-22", "PREV_RIGHT_EDGE_ID":"20", "LEFT_FACE_ID":"3", "RIGHT_FACE_ID":"6"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[9,6,21,6]}, "properties":{"EDGE_ID":"12", "START_NODE_ID":"8", "END_NODE_ID":"9", "NEXT_LEFT_EDGE_ID":"20", "PREV_LEFT_EDGE_ID":"-22", "NEXT_RIGHT_EDGE_ID":"22", "PREV_RIGHT_EDGE_ID":"-13", "LEFT_FACE_ID":"6", "RIGHT_FACE_ID":"-1"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[9,35,13,35]}, "properties":{"EDGE_ID":"25", "START_NODE_ID":"21", "END_NODE_ID":"22", "NEXT_LEFT_EDGE_ID":"-25", "PREV_LEFT_EDGE_ID":"-25", "NEXT_RIGHT_EDGE_ID":"25", "PREV_RIGHT_EDGE_ID":"25", "LEFT_FACE_ID":"1", "RIGHT_FACE_ID":"1"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[9,6,9,14]}, "properties":{"EDGE_ID":"22", "START_NODE_ID":"8", "END_NODE_ID":"15", "NEXT_LEFT_EDGE_ID":"21", "PREV_LEFT_EDGE_ID":"-12", "NEXT_RIGHT_EDGE_ID":"12", "PREV_RIGHT_EDGE_ID":"-9", "LEFT_FACE_ID":"-1", "RIGHT_FACE_ID":"6"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[25,30,31,30,31,40,17,40,17,30,25,30]}, "properties":{"EDGE_ID":"2", "START_NODE_ID":"2", "END_NODE_ID":"2", "NEXT_LEFT_EDGE_ID":"3", "PREV_LEFT_EDGE_ID":"-3", "NEXT_RIGHT_EDGE_ID":"-2", "PREV_RIGHT_EDGE_ID":"-2", "LEFT_FACE_ID":"2", "RIGHT_FACE_ID":"-1"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[21,6,35,6]}, "properties":{"EDGE_ID":"13", "START_NODE_ID":"9", "END_NODE_ID":"10", "NEXT_LEFT_EDGE_ID":"18", "PREV_LEFT_EDGE_ID":"-20", "NEXT_RIGHT_EDGE_ID":"-12", "PREV_RIGHT_EDGE_ID":"-14", "LEFT_FACE_ID":"7", "RIGHT_FACE_ID":"-1"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[21,22,35,22]}, "properties":{"EDGE_ID":"7", "START_NODE_ID":"17", "END_NODE_ID":"18", "NEXT_LEFT_EDGE_ID":"8", "PREV_LEFT_EDGE_ID":"6", "NEXT_RIGHT_EDGE_ID":"-19", "PREV_RIGHT_EDGE_ID":"17", "LEFT_FACE_ID":"-1", "RIGHT_FACE_ID":"4"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[21,6,21,14]}, "properties":{"EDGE_ID":"20", "START_NODE_ID":"9", "END_NODE_ID":"14", "NEXT_LEFT_EDGE_ID":"-9", "PREV_LEFT_EDGE_ID":"12", "NEXT_RIGHT_EDGE_ID":"13", "PREV_RIGHT_EDGE_ID":"10", "LEFT_FACE_ID":"6", "RIGHT_FACE_ID":"7"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[35,14,21,14]}, "properties":{"EDGE_ID":"10", "START_NODE_ID":"13", "END_NODE_ID":"14", "NEXT_LEFT_EDGE_ID":"-20", "PREV_LEFT_EDGE_ID":"18", "NEXT_RIGHT_EDGE_ID":"17", "PREV_RIGHT_EDGE_ID":"-19", "LEFT_FACE_ID":"7", "RIGHT_FACE_ID":"4"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[21,14,21,22]}, "properties":{"EDGE_ID":"19", "START_NODE_ID":"14", "END_NODE_ID":"17", "NEXT_LEFT_EDGE_ID":"-6", "PREV_LEFT_EDGE_ID":"9", "NEXT_RIGHT_EDGE_ID":"-10", "PREV_RIGHT_EDGE_ID":"-7", "LEFT_FACE_ID":"3", "RIGHT_FACE_ID":"4"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[25,30,25,35]}, "properties":{"EDGE_ID":"3", "START_NODE_ID":"2", "END_NODE_ID":"3", "NEXT_LEFT_EDGE_ID":"-3", "PREV_LEFT_EDGE_ID":"2", "NEXT_RIGHT_EDGE_ID":"2", "PREV_RIGHT_EDGE_ID":"3", "LEFT_FACE_ID":"2", "RIGHT_FACE_ID":"2"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[35,6,47,6]}, "properties":{"EDGE_ID":"14", "START_NODE_ID":"10", "END_NODE_ID":"11", "NEXT_LEFT_EDGE_ID":"16", "PREV_LEFT_EDGE_ID":"-18", "NEXT_RIGHT_EDGE_ID":"-13", "PREV_RIGHT_EDGE_ID":"-16", "LEFT_FACE_ID":"8", "RIGHT_FACE_ID":"-1"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[35,14,47,14]}, "properties":{"EDGE_ID":"11", "START_NODE_ID":"13", "END_NODE_ID":"12", "NEXT_LEFT_EDGE_ID":"15", "PREV_LEFT_EDGE_ID":"-17", "NEXT_RIGHT_EDGE_ID":"-18", "PREV_RIGHT_EDGE_ID":"16", "LEFT_FACE_ID":"5", "RIGHT_FACE_ID":"8"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[35,6,35,14]}, "properties":{"EDGE_ID":"18", "START_NODE_ID":"10", "END_NODE_ID":"13", "NEXT_LEFT_EDGE_ID":"10", "PREV_LEFT_EDGE_ID":"13", "NEXT_RIGHT_EDGE_ID":"14", "PREV_RIGHT_EDGE_ID":"-11", "LEFT_FACE_ID":"7", "RIGHT_FACE_ID":"8"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[35,22,47,22]}, "properties":{"EDGE_ID":"8", "START_NODE_ID":"18", "END_NODE_ID":"19", "NEXT_LEFT_EDGE_ID":"-15", "PREV_LEFT_EDGE_ID":"7", "NEXT_RIGHT_EDGE_ID":"-17", "PREV_RIGHT_EDGE_ID":"15", "LEFT_FACE_ID":"-1", "RIGHT_FACE_ID":"5"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[35,14,35,22]}, "properties":{"EDGE_ID":"17", "START_NODE_ID":"13", "END_NODE_ID":"18", "NEXT_LEFT_EDGE_ID":"-7", "PREV_LEFT_EDGE_ID":"-10", "NEXT_RIGHT_EDGE_ID":"11", "PREV_RIGHT_EDGE_ID":"-8", "LEFT_FACE_ID":"4", "RIGHT_FACE_ID":"5"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[36,38,38,35,41,34,42,33,45,32,47,28,50,28,52,32,57,33]}, "properties":{"EDGE_ID":"4", "START_NODE_ID":"5", "END_NODE_ID":"6", "NEXT_LEFT_EDGE_ID":"-5", "PREV_LEFT_EDGE_ID":"-4", "NEXT_RIGHT_EDGE_ID":"4", "PREV_RIGHT_EDGE_ID":"5", "LEFT_FACE_ID":"-1", "RIGHT_FACE_ID":"-1"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[41,40,45,40,47,42,62,41,61,38,59,39,57,36,57,33]}, "properties":{"EDGE_ID":"5", "START_NODE_ID":"7", "END_NODE_ID":"6", "NEXT_LEFT_EDGE_ID":"-4", "PREV_LEFT_EDGE_ID":"-5", "NEXT_RIGHT_EDGE_ID":"5", "PREV_RIGHT_EDGE_ID":"4", "LEFT_FACE_ID":"-1", "RIGHT_FACE_ID":"-1"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[47,14,47,22]}, "properties":{"EDGE_ID":"15", "START_NODE_ID":"12", "END_NODE_ID":"19", "NEXT_LEFT_EDGE_ID":"-8", "PREV_LEFT_EDGE_ID":"11", "NEXT_RIGHT_EDGE_ID":"-16", "PREV_RIGHT_EDGE_ID":"8", "LEFT_FACE_ID":"5", "RIGHT_FACE_ID":"-1"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[47,6,47,14]}, "properties":{"EDGE_ID":"16", "START_NODE_ID":"11", "END_NODE_ID":"12", "NEXT_LEFT_EDGE_ID":"-11", "PREV_LEFT_EDGE_ID":"14", "NEXT_RIGHT_EDGE_ID":"-14", "PREV_RIGHT_EDGE_ID":"-15", "LEFT_FACE_ID":"8", "RIGHT_FACE_ID":"-1"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[4, 31]}, "properties":{"NODE_ID":"20", "EDGE_ID":"26", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[8, 30]}, "properties":{"NODE_ID":"1", "EDGE_ID":"1", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[9, 6]}, "properties":{"NODE_ID":"8", "EDGE_ID":"12", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[9, 35]}, "properties":{"NODE_ID":"21", "EDGE_ID":"25", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[9, 14]}, "properties":{"NODE_ID":"15", "EDGE_ID":"21", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[9, 22]}, "properties":{"NODE_ID":"16", "EDGE_ID":"6", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[13, 35]}, "properties":{"NODE_ID":"22", "EDGE_ID":"-25", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[20, 37]}, "properties":{"NODE_ID":"4", "EDGE_ID":"0", "FACE_ID":"2"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[21, 14]}, "properties":{"NODE_ID":"14", "EDGE_ID":"19", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[21, 22]}, "properties":{"NODE_ID":"17", "EDGE_ID":"7", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[21, 6]}, "properties":{"NODE_ID":"9", "EDGE_ID":"20", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[25, 30]}, "properties":{"NODE_ID":"2", "EDGE_ID":"2", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[25, 35]}, "properties":{"NODE_ID":"3", "EDGE_ID":"-3", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[35, 14]}, "properties":{"NODE_ID":"13", "EDGE_ID":"17", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[35, 6]}, "properties":{"NODE_ID":"10", "EDGE_ID":"18", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[35, 22]}, "properties":{"NODE_ID":"18", "EDGE_ID":"8", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[36, 38]}, "properties":{"NODE_ID":"5", "EDGE_ID":"4", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[41, 40]}, "properties":{"NODE_ID":"7", "EDGE_ID":"5", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[47, 14]}, "properties":{"NODE_ID":"12", "EDGE_ID":"15", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[47, 6]}, "properties":{"NODE_ID":"11", "EDGE_ID":"-14", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[47, 22]}, "properties":{"NODE_ID":"19", "EDGE_ID":"-15", "FACE_ID":"0"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[57, 33]}, "properties":{"NODE_ID":"6", "EDGE_ID":"-4", "FACE_ID":"0"}}
]}

To retrieve topology features, the following example specifies the topology, base_table, and geom_col parameters (where grom_col refers to the topology column):

http://example:8080/mapviewer/dataserver/tilsmenv?topology=city_data&base_table=land_parcels&geom_col=feature

The response to this request is similar to the following:

{"type":"TopologyFeatures",
"topology":"CITY_DATA",
"topology_id":5,
"topology_owner":"TILSZUSER",
"tolerance":5.0E-5,
"srs":0,
"table_schema":"TILSZUSER",
"table_name":"LAND_PARCELS",
"topo_column":"FEATURE",
"layer_id":1,
"layer_type":"POLYGON",
"layer_level":0,
"child_layer":0,
"node_sequence":"CITY_DATA_NODE_S",
"edge_sequence":"CITY_DATA_EDGE_S",
"face_sequence":"CITY_DATA_FACE_S",
"feature_sequence":"CITY_DATA_TG_S",
"digits_right_decimal":16,
"attr_names":["FEATURE_NAME"],
"attr_types":["string"],
"features":[
{"type":"topology", "tg_id":4, "primitives":[{"topo_id":3,"topo_type":3},{"topo_id":6,"topo_type":3}], "properties":{"FEATURE_NAME":"P1"}},
{"type":"topology", "tg_id":5, "primitives":[{"topo_id":4,"topo_type":3},{"topo_id":7,"topo_type":3}], "properties":{"FEATURE_NAME":"P2"}},
{"type":"topology", "tg_id":6, "primitives":[{"topo_id":5,"topo_type":3},{"topo_id":8,"topo_type":3}], "properties":{"FEATURE_NAME":"P3"}},
{"type":"topology", "tg_id":7, "primitives":[{"topo_id":2,"topo_type":3}], "properties":{"FEATURE_NAME":"P4"}},
{"type":"topology", "tg_id":8, "primitives":[{"topo_id":1,"topo_type":3}], "properties":{"FEATURE_NAME":"P5"}}
]}

To specific primitive faces, edges, and nodes, the following example define the primitive identifiers:

http://example:8080/mapviewer/dataserver/tilsmenv?topology=city_data&face_ids=-1&edge_ids=3,4&node_ids=5

The response to this request is similar to the following:

{"type":"TopologyPrimitives",
"topology":"city_data",
"srs":0,
"bbox":[0, 0, 57, 38],
"face_attr_names":["FACE_ID","BOUNDARY_EDGE_ID","ISLAND_EDGE_ID_LIST","ISLAND_NODE_ID_LIST"],
"face_attr_types":["integer","integer","array:integer","array:integer"],
"edge_attr_names":["EDGE_ID","START_NODE_ID","END_NODE_ID","NEXT_LEFT_EDGE_ID","PREV_LEFT_EDGE_ID","NEXT_RIGHT_EDGE_ID","PREV_RIGHT_EDGE_ID","LEFT_FACE_ID","RIGHT_FACE_ID"],
"edge_attr_types":["integer","integer","integer","integer","integer","integer","integer","integer","integer"],
"node_attr_names":["NODE_ID","EDGE_ID","FACE_ID"],
"node_attr_types":["integer","integer","integer"],
"primitives":[
{"type":"Face", "properties":{"FACE_ID":"-1", "BOUNDARY_EDGE_ID":"0", "ISLAND_EDGE_ID_LIST":[-1,-2,4,6]}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[25,30,25,35]}, "properties":{"EDGE_ID":"3", "START_NODE_ID":"2", "END_NODE_ID":"3", "NEXT_LEFT_EDGE_ID":"-3", "PREV_LEFT_EDGE_ID":"2", "NEXT_RIGHT_EDGE_ID":"2", "PREV_RIGHT_EDGE_ID":"3", "LEFT_FACE_ID":"2", "RIGHT_FACE_ID":"2"}},
{"type":"Edge", "geometry":{"type":"LineString", "coordinates":[36,38,38,35,41,34,42,33,45,32,47,28,50,28,52,32,57,33]}, "properties":{"EDGE_ID":"4", "START_NODE_ID":"5", "END_NODE_ID":"6", "NEXT_LEFT_EDGE_ID":"-5", "PREV_LEFT_EDGE_ID":"-4", "NEXT_RIGHT_EDGE_ID":"4", "PREV_RIGHT_EDGE_ID":"5", "LEFT_FACE_ID":"-1", "RIGHT_FACE_ID":"-1"}},
{"type":"Node", "geometry":{"type":"Point", "coordinates":[36, 38]}, "properties":{"NODE_ID":"5", "EDGE_ID":"4", "FACE_ID":"0"}}
]}

Parent topic: Map Data Server Request Parameters

3.1.3 Interpreting Data Returned from the Map Data Server

The map data server returns data in a compressed GeoJSON format. Some minor changes and additions to the standard GeoJSON are made to improve performance and the usefulness of the information.

The following is a sample response:

{"type":"FeatureCollection",
"collectionName":"theme1",
"srs":3857,
"geodetic":false,
"bbox":[-17566686.86258, 2414218.89842, -7905675.57465, 8629389.76988],
"attr_names":["CITY","STATE_ABRV","POP90","RANK90"],
"attr_types":["string","string","double","double"],
"features":[
{"type":"Feature","_id":"AAASQ3AAEAAAAMbAAA","geometry": {"type":"Point", "coordinates":[-119.99823, 38.9052]},"properties":{"CITY":"SOUTH LAKE TAHOE", "SALES":"125.8", "NAME":"FACTORY STORES AT THE Y", "_label_":"FACTORY STORES AT THE Y"},"styles":{"rendering":{"style":"M.SMALL CIRCLE"},"labeling":{"style":"T.RED STREET", "columns":["_label_"]}}},
{"type":"Feature","_id":"AAASQ3AAEAAAAMbAAB","geometry": {"type":"Point", "coordinates":[-121.95073, 37.53356]},"properties":{"CITY":"FREMONT", "SALES":"186.8", "NAME":"OHLONE VILLAGE", "_label_":"OHLONE VILLAGE"},"styles":{"rendering":{"style":"M.SMALL CIRCLE"},"labeling":{"style":"T.RED STREET", "columns":["_label_"]}}},
{"type":"Feature","_id":"AAASQ3AAEAAAAMbAAC","geometry": {"type":"Point", "coordinates":[-118.48844, 34.02353]},"properties":{"CITY":"SANTA MONICA", "SALES":"9.1", "NAME":"SANTA MONICA PLACE", "_label_":"SANTA MONICA PLACE"},"styles":{"rendering":{"style":"M.SMALL CIRCLE"},"labeling":{"style":"T.RED STREET", "columns":["_label_"]}}},
{"type":"Feature","_id":"AAASQ3AAEAAAAMbAAD","geometry": {"type":"Point", "coordinates":[-118.55093, 34.42104]},"properties":{"CITY":"SANTA CLARITA", "SALES":"52.6", "NAME":"VALENCIA TOWN CENTER", "_label_":"VALENCIA TOWN CENTER"},"styles":{"rendering":{"style":"M.SMALL CIRCLE"},"labeling":{"style":"T.RED STREET", "columns":["_label_"]}}},
{"type":"Feature","_id":"AAASQ3AAEAAAAMbAAE","geometry": {"type":"Point", "coordinates":[-122.56007, 38.08187]},"properties":{"CITY":"NOVATO", "SALES":"119.1", "NAME":"VINTAGE OAKS AT NOVATO", "_label_":"VINTAGE OAKS AT NOVATO"},"styles":{"rendering":{"style":"M.SMALL CIRCLE"},"labeling":{"style":"T.RED STREET", "columns":["_label_"]}}}]}

The response contains a minimal header plus an array of features. The header includes the spatial reference system (srs) ID and the minimum bounding box of the result data. The array of features includes attribute names and their types. Possible type names include: "byte","short","int","long","float","double","char","string","boolean", "date"

For each feature, the following fields apply:

  • type: Always Feature.

  • _id: Optional ID or key attribute.

  • geometry: The actual geometry encoded in the modified GeoJSON format.

  • properties: An object containing all the properties (name-value pairs) for the feature.

  • styles: An optional styling information object. Contains two embedded objects, rendering and labeling, which share the same structure: basically an object containing a style field and an optional columns array. Currently only predefined themes support including styling information in the response; a dynamic theme's response contains no styling information.

  • label_box: A 4-element array specifying the minX, minY, maxX, and maxY of the label box. Only a polygon can have a label box.

Note that the labeling text is always included as a pseudo-property with the name _label_ in the property list.

Parent topic: Map Visualization Component Map Data Server

3.1.4 Map Data Server Error Handling

If the map data server cannot process a data request, it will send a JSON response containing an error object. This JSON error object may look like the following:

{"error":
  {"code": "ora-500",
   "message": "Table requested does not exist",
   "details": "maybe a stack trace here..."
  }
}

In the preceding JSON object, code is the error code known only to the map data serve, message contains a short message that can be displayed to the end user in a warning dialog, and details is an optional field that may contain more details (such as the stack trace if included).

Parent topic: Map Visualization Component Map Data Server