Introduction

The Data Inspector addresses developers, data scientists, and business analysts. Inspecting data on the HERE platform – structurally as well as visually – can help you understand the data’s value for your use case or can help you debug the data that you produce on the platform yourself.

The Data Inspector essentially consists of these two interfaces:

  • One that lets you programmatically create a visualization for Protobuf-encoded data by defining which elements of your data shall be presented and in what way. This interface is called a GeoJSON rendering plugin and it transforms your Protobuf-encoded data to GeoJSON.

  • The point-and-click UI that lets you interact with the data. It offers visual clues on where your data is located and how it is distributed geographically. It lets you view the data visually on a map using a GeoJSON plugin to transform the data and a GeoJSON rendering engine to visualize it. In case the data is already formatted as GeoJSON, it renders directly.

The platform lets you attach a GeoJSON plugin to your schema. So, when you share your data with someone, the schema and the plugin are implicitly shared with it. This way, they can benefit from the visualization that you've created. In fact, a number of platform data sets already have a schema and plugin attached so that you can enjoy automatic decoding and visualization for these data layers out of the box.

The Data Inspector allows visualizing the following types of data:

  • Protobuf-encoded data visualized with custom GeoJSON rendering plugins:

    Figure 1: Fueling stations
    Figure 3: Multi-carriageways and motorway interchanges with ramps grouped to enable creation of a basic representation
  • GeoJSON data visualized with the dedicated GeoJSON rendering engine:

    Figure 4: Outlines of Berlin districts partitioned by the geographic center of each polygon
  • Several layers from the HERE Map Content catalog (Cartography, Roads - Topology & Geometry, and Building Footprints) visualized out of the box with the special rendering engine:

    Figure 5: Building footprints
  • Vehicle sensor data (Sensor Data Ingestion Interface (SDII)) visualized with the dedicated rendering engine that requires no specific rendering plugin:

    Figure 6: Vehicle sensor data (SDII)

The Data Inspector is available as a component integrated in the HERE platform portal as well as in form of a library. For most cases, the portal application is all you need. You can even develop a rendering plugin there. The Data Inspector Library lets you create a customized Data Inspector tool for special cases that you might have. For more information, see the use cases in the chapter below.

Why Use the Data Inspector Library

The Data Inspector Library allows you to do the following:

Discover Platform Data Coverage

Whenever searching for certain types of data stored in the platform, one of the first things you may be interested in is where that data is available geographically.

For HERETiled layers, the Data Inspector provides a coverage map (as a green overlay on top of the basemap) that shows the geographical distribution of layer data on a global or local sale, depending on a zoom level.

Figure 7: Coverage map

But if the data is generically partitioned, then there is no way of knowing where the data would be at until you load the data itself – and that can be a very heavy operation. In that case, the platform still offers you the possibility to state in which countries your data is available through a layer description.

Inspect Platform Data

The information on the layer's page in the portal can help you out, of course, but to know more about the data, use the Data Inspector. This tool brings lots of data inspection capabilities, including those listed below:

  • Learn in more detail where exactly tiles with data can be expected.
  • View where the larger tiles of data (in KB or MB) are available.
  • Visualize the layer content's geometry of one or more tiles on the basemap to see if the geometry is correct.
  • Inspect layers with multiple data levels by selecting one specific level and visualizing only the data that is stored on that specific level.
  • Study the data structure and attribute values in a specific tile, so that you can find out if it fits your purpose without having to code a single line.
  • Inspect non-tiled (generically partitioned) data that cannot be visualized from within the Data Inspector as a list of partitions.

For more information on inspection capabilities, see the How To chapters.

Inspect Pipeline Outputs

As a platform pipeline developer, you take platform data as your pipeline input. Then, to ensure that every processing stage fits your overall purpose, you can inspect your pipeline output with the .

The Data Inspector Library allows you to:

  • View visualized partition data directly in the platform Data Inspector. For this, though, your schema with rendering plugins must be deployed to the platform and bundled with a layer. Equally, your pipeline application must be deployed to the platform, configured, and launched in Pipeline API.

  • View a local (off-line) partition exactly as it will be visualized in the portal. You can also view a local schema (and rendering plugin) exactly as it would be visualized in the portal. This is the convenient way since all the pipeline development and testing is happening on your local staging environment. Once completed, you deploy a perfectly finetuned pipeline application to the platform.

For more information, see Pipelines Developer Guide.

Scale Visualization with Custom Plugins

The platform is extremely flexible in how it allows you to store and structure your data. Every layer can be tiled or non-tiled, and every layer can have its own data format. However, you are recommended to store your data in HERE tiles in GeoJSON or in Protobuf with a well-defined Protobuf schema.

HERETiled GeoJSON layers can be instantly visualized by the Data Inspector.

And HERETiled Protobuf layers can be visualized with custom JavaScript plugins that are used to convert Protobuf-encoded data to GeoJSON and visualize it. To simplify rendering plugin development, the Data Inspector includes an integrated environment where you can code and immediately test your rendering plugins on a specific Protobuf schema.

For more information on rendering plugins, see Create Rendering Plugins.

Build Custom Apps

Once data is stored in the platform, you are not limited to the visualization options offered online. With the Data Inspector Library, you can create, for instance, complete off-platform web dashboards or admin web tools that can visualize your data with the JavaScript libraries of your own preference. The Data Inspector Library allows you to access platform data directly with JavaScript and to show that data on top of your preferred maps libraries (Leaflet, OpenLayers, and the like).

For more information, see Library Modules Overview.

Prerequisites

To build and run applications based on the Data Inspector Library, you need the following:

  • Have a valid platform user account.
  • Obtain repository and platform credentials.
  • Install Node.js at least version 10.14.0. However, it is recommended to use Node.js version 12.x for the best Data Inspector Library experience.
  • Configure the npm package manager, shipped along with Node.js, that is needed to run the commands in this guide.
  • Possess the knowledge of HTML/CSS, JavaScript, and TypeScript.
  • Be familiar with the basic platform concepts.
  • Install a WebGL-enabled browser to be able to see visualizations. The latest versions of Google Chrome, Mozilla Firefox, and Apple Safari all support this technology. To test your browser, go to https://get.webgl.org/.

Next Steps

To get started with the Data Inspector Library, follow these steps:

  1. Get Your Credentials
  2. Install the Data Inspector Library
  3. Try the Basic Use Case

For the terms and conditions covering this documentation, see the HERE Documentation License.

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