118 lines
4.2 KiB
Markdown
118 lines
4.2 KiB
Markdown
# Data Views
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## Introduction
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Publishers and users of data want data presented in tables, graphs maps to make it more *human* "readable".[^1] We use the term "view" or "data view" ofr all these various ways of presenting data in more human "readable" ways.
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[^1]: for an introduction to the power and art of visual presentation data see e.g. Tufte *Visualizing Information*.
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```mermaid
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graph LR
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data[Your Data] --> table[Table]
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data --> grap[Graph]
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```
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At base, views need:
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* **A descriptive language**: for *specifying* views such as tables, graphs and maps (and their source data).
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* **Rendering tools**: take those specifications and render actual "live on the web" tables, graphs and maps from those specifications (and their source data)
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In addition, we may want:
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* **Wizards**: to enable (non-technical) users to create tables, graphs, maps etc -- and to select the input data to power them.
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* **Explorers**: that build on the views and wizards to allow users to do interactive data exploratio via live filtering and viewing.
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* **Dashboards** that combine tables, charts, maps etc (often with widgets that allow users to adjust these e.g. to select a country that updates associated charts).
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>[!tip]Often when we say "view" we identify with the particular presentation such as the table or graph. E.g. we say "this table is a view of that data". However, when you stop and think, strictly a view is more than that, for example it includes the title for the table. Formally, for us a view will include the combination of the presentation specification, the data sources that feed, plus any general metadata such as a title and description.
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## Definitions
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* Preview: a display (of a sample) of a resource
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* Previewer: a method for previewing specific raw data types e.g. csv, excel, json, xml, text, geojson etc …
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* Viz: visualizations e.g. table, graph, map, ...
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* Viz Builder: a UI for creating graphs, maps etc
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* Query UI: a UI for building queries of a dataset
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* Explorer: Query UI + Viz Builder + Viz (renderer)
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## Features
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Definitions for feature clusters
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* View: "(pre)view" a variety of data formats, most importantly tabular and geodata, and extending to PDFs, JSON HTML etc.
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* Tabular:
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* Geo:
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* Chart:
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* Maps:
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* Everything else: this is more a preview
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* Pluggable system
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* Resource proxy (cors issues)
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* [Data Explorer][]: think "tableau lite", a rich app for querying/loading data and then displaying that in tables, charts, maps etc.
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* Builders:
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* Query Builder:
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* Chart Builder: a wizard for building charts
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* Map Builder
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* Lite: set popups etc.
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* Complex: think carto
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* Rich Viz: bespoke, complex visualization
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* Dashboard: something that has many widgets displayed at once
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* Basic: no linkage between widgets (basic controls)
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* Complex: linkage between widgets (e.g. zooming on the map changes the map, or clicking the map changes the charts)
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[Data Explorer]: /docs/dms/data-explorer
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## CKAN v2
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In CKAN v2 and earlier this is provided by the internal view object plus ReclineJS.
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* Controller / Template = frontend controller, templating library or even browser JS
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* "Data Factory" is a fancy name for any business logic that automatically adds views to a dataset. In CKAN 2 this happens as part of the resource creation logic
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```mermaid
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graph TD
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subgraph Backend
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dataset --user uploads --> storage
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dataset --user uploads --> metastore
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end
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subgraph "Data Factory"
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metastore --> viewgen[View Enhancer]
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viewgen --> metastore
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end
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user -- user creates/edits a view --> metastore
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subgraph "Controller / Template"
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storage -- download the file --> visitor
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metastore --renders table--> visitor
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metastore --renders graph--> visitor
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end
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```
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The sequence of it ...
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```mermaid
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graph LR
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fileupload --> store
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store --> enhance[Enhance - auto add views]
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enhance --> render
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enhance --> useredit[User edits views]
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useredit --> render
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```
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## CKAN v3
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In CKAN v3 and DataHub these are provied through the use of Frictionless (Data Package) "Views" and associated tooling.
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See:
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* https://github.com/datopian/datapackage-views-js
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* https://github.com/frictionlessdata/datapackage-render-js
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* [Data Explorer][] page in this site.
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For more on the technical background see the [Views Design page »](/docs/dms/views/design).
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