Producers and consumers of data want to see views on their data in the forms of tables, graphs and maps.

This guide shows you how you can create beautiful views for your data and push them to the DataHub.

Features

• Simple things are simple: adding a bar chart or line chart is fast and easy – seconds to do and requiring minimal knowledge. Views are created in a simple declarative syntax
• Powerful and extensible: complex and powerful graphing is also powerful.
• Reuse: leverage the power of existing specs like Vega (and tools like Vega and Plotly)
• Transform your data prior to visualization
• Composable: the views spec is independent but composable with other data package specs (and even usable on its own)

How it works

You can add a view for your data simply by describing your view in a simple declarative syntax (in JSON) and then adding to the datapackage.json for your dataset.

For example, suppose you have data in a csv that looks like this:

Then you could describe your view like this:

{
  "type": "line",
  "group": "x",
  "series": [ "y", "z" ]
}

Finally, you need to connect your view with the underlying data source in the datapackage.json

...
"resources": [
  {
  	"name": "mydata"
  	"path": "mydata.csv",
  	"schema": ...
  }
],
"views": [
  {
  	"name": "graph-1",
  	"title": "My awesome view",
  	// the data to connect to this view
  	"resources": ["mydata"],
  	// specType here is optional as simple is the default
  	"specType": "simple",
  	"spec": {
  		"type": "line",
  		"group": "x",
  		"series": [ "y", "z" ]
  	}
  }
]

Axis titles and suffixes for axis ticks

In the spec property of the views, you also can set suffixes for axis ticks. For example, you might have numbers that are in billions so you want to append B letter for all tick labels. You'd simply have ySuffix or xSuffix property in your spec (see the snippet below). Another common situation would be if you need to set custom axis titles, for which we have xTitle and yTitle properties:

...
"views": [
  {
    ...
    "spec": {
      ...,
      "ySuffix": "B",
      "xTitle": "my custom abscissa title",
      "yTitle": "my custom ordinate title"
    }
  }
]

To learn more see the examples live examples below.

Examples

In this section, examples of using Data Package views are provided. Each example has a README section with small tutorial.

Simple graph spec

Simple graph spec is the easiest and quickest way to specify a view in a Data Package. Using simple graph spec publishers can generate graphs, e.g., line and bar charts.

• Simple Graph Spec Tutorial

Vega graphs

Publishers can also describe graphs using Vega specifications:

• Vega Graph Spec Tutorial - Yields of Barley
• Vega Graph Spec Tutorial - US presidents
• Vega Graph Spec Tutorial - US Airports

Maps

At the moment, we only support .geojson format:

• GeoJSON Tutorial

Tables and Transforms

In the following examples, we demonstrate how transforms can be used in Data Package views. Transformed data will be displayed as table views.

• Filter & Formula
• Sample
• Aggregate

More Information

• [Details of how the tooling works are in Views Developer guide][views-dev]
• Views spec (draft)