This chapter defines a set of preconditions that must be in place for the Data Inspector to successfully visualize data. These preconditions relate to the following areas:
The Data Inspector Library supports two types of partitioning schemes – HERE Tile partitioning and generic partitioning.
HERE Tile partitioning is a method for storing map data where layers contain rectangular geographic tiles that represent an area of the map. These tiles are also known as partitions. If you use HERE Tile partitioning, you can take advantage of the OLP libraries and APIs to perform geo-related tasks.
Generic partitioning is the simplest form of partitioning where partition names have no semantic meaning. Generic partitioning is best suited to data other than map data, such as search index data. With the Partitions List panel, you can view non-visualized partition data from generic layers.
For more information on partitioning schemes, see Partitions in the Data User Guide.
With the Data Inspector Library, you can visualize two types of layers – versioned an volatile.
Versioned layers store slowly changing data that must remain logically consistent with other layers in the catalog. When you want to update a catalog of versioned layers, all the layers related to the update (and partitions within a layer) must be updated in one publication so that they can be versioned together.
Volatile layers store data in the key/value form where values for a given key can change, and only the latest value is retrievable. As new data is published, old data is overwritten. Volatile layers use in-memory storage. Storing data in memory helps reduce data access latency and provides applications with consistently high throughput.
Regarding other layer types, the Data Inspector cannot visualize stream and index layers. Nonetheless, with the Partitions List panel, you can still inspect those layer partitions that can be neither visualized (no renderer plugin) nor decoded (no data schema bundled with the layer).
For more information on OLP layer types, see Layers in the Data User Guide.
You can visualize different types of data from a local file or from an OLP catalog. Both data sources support a wide range of formats.
GeoJSON is a format for encoding a variety of geographic data structures that supports the following geometry types:
MultiPointto describe addresses and locations.
MultiLineStringto describe streets, highways, and boundaries.
MultiPolygonto describe countries, provinces, and tracts of land.
These features do not have to describe only "real-world" entities. They can also describe invisible entities such as areas of mobile coverage or IoT geofences.
The Data Inspector Library provides out-of-the-box support for rendering GeoJSON data with the
GeoJsonDataSource conforms to the GeoJSON specification and supports all geometry types from the GeoJSON format. You can use a GeoJSON file as a local data source, or you can connect to an OLP catalog that stores GeoJSON data.
The data source supports a set of styling properties of the
Feature objects to customize the appearance of geometries. For more information, see Style GeoJSON Visualization.
SDII is a multifunctional web service for collecting and validating data generated by sensors. It connects equipment manufacturers and data vendors to the OLP. Messages sent through this interface must be structured and encoded according to the Sensor Ingestion Interface Specification. You can use this interface to post messages with sensor data to the OLP. For more information, see the Sensor Ingestion Interface Specification.
The Data Inspector Library can render SDII data out of the box from OLP or from a local file with the
SdiiDataSource class and supports the following:
- Static display of data
- Animation of vehicle paths
- Visualization of road signs
- Visualization of live data streams with a configurable auto-refresh rate
- Hazard warnings and other path events
You can filter the data by type, that is paths, road signs, hazard warnings, and other path events.
HERE Map Content is a catalog within the HERE OLP Data Service. It integrates highly accurate map data (including topology nodes and segments, assorted attributes, administrative data, and so on) from various sources. For more information, see HERE Map Content Specification.
The Data Inspector Library can render HERE Map Content data out of the box from the OLP using the
RibDataSource. It supports these layers from the HERE Map Content catalog:
- Building Footprints
- Road Topology & Geometry
In addition to the visualization of geometry from the HERE Map Content layers, the Library can provide this data to other data sources. This can be used to visualize various data with no geometry information in it but that can be mapped to HERE Map Content geometry. For more information, see GeoJSON Data.
The Data Inspector Library allows you to visualize data in any format that is not supported by the standard rendering engine. There are a few preconditions that must be met:
- Your should encode your data with Google Protocol Buffers and publish it to a catalog layer whose content type is
- You should upload your protobuf schema to OLP and associate it with a layer that contains your data.
- You should create your own renderer plugin and include it in your protobuf schema.
This way, the Data Inspector Library can decode your partitions and render them with the renderer plugin. The renderer plugin returns the GeoJSON representation of the partition that is then rendered by the
Please note that for your datasets to be visualized correctly, it is your responsibility to develop and thoroughly test your renderer plugins.