# ohsome2X

> Query OSM History Data (count, length, area) about specific OSM Features or OSM User activity (user-count) for your areas of interest.

> Input: Accepts GeoJSON or PostgreSQL/PostGIS as input source.

> Output: Creates a GeoJSON File or new result table in your PostgreSQL/PostGIS database. 
The package includes a library with a single class to run. 

Additionally it includes `oshome2x-cli`, a command-line tool with a configuration wizard to create and run a query-configuration-JSON.

This library/tool makes use of the Ohsome-API (https://api.ohsome.org) as data backend and many other great open-source libraries. 

This software is developed by [HeiGIT](https://heigit.org):

<img src="https://heigit.org/wp-content/uploads/2018/01/HeiGIT_Logo_cut-505x100@2x.png" alt="HeiGIT Logo" height="80px" width="404px">

## Install

For use as library in Node.js:
```sh
$ npm install ohsome2x
```
To run the command-line wizard:
```sh
$ npx ohsome2x-cli
```


## Usage
There are two ways how you can use ohsome2x.

1. Use it as library in another Node.js project. You find the built library in the `/dist` folder after executing `npm run build`
2. Use the interactive command line interface. 

    Run: 
   ```sh
   $ npx ohsome2x-cli
   OR 
   $ node ./ohsome2x-cli/ohsome2x-cli.js
   ```
   
## Example

### Query the number of buildings in a bbox around Heidelberg in a yearly resolution from 2008 to 2020

##### Step 1. You need some input (one or many polygons): heidelberg.geojson
```json
{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {"id": "Heidelberg"},
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [ [8.625984191894531, 49.38527827629032],
            [8.735504150390625, 49.38527827629032],
            [8.735504150390625, 49.433975502014675],
            [8.625984191894531, 49.433975502014675],
            [8.625984191894531, 49.38527827629032]
          ]]}}]}
```

##### Step 2. Specify your query as JSON (you can use the commandline wizard to create this): myquery.json
```json
{
  "ohsomeQuery": {
    "queryType": "elements/count/groupBy/boundary",
    "keys": "building",
    "values": "",
    "types": "polygon",
    "time": "2008/2020/P1Y"
  },
  "source": {
    "geometryId": "id",
    "name": "heidelberg.geojson",
    "store": { "path": "heidelberg.geojson", "type": "geojson" }
  },
  "target": {
    "horizontalTimestampColumns": false,
    "createGeometry": true,
    "transformToWebmercator": false,
    "storeZeroValues": true,
    "computeValuePerArea": true,
    "name": "heidelberg_buildings_count.geojson",
    "store": { "path": "heidelberg_buildings_count.geojson", "type": "geojson" }
  }
}
```

##### Step 3. Run the Query
```bash
$ npx ohsome2x-cli run --conf myquery.json
```



## API

Node:
```js
const Ohsome2X = require('ohsome2x');

// you can create this config using the command-line wizard, run: npx ohsome2x-cli
const config = {
                ohsomeQuery: {...},
                source: {...},
                target: {...}
}                               

const ohsome2x = new Ohsome2X(config);

// This will return a Promise
ohsome2x.run().catch(console.log);
```

TypeScript:
```typescript
import Ohsome2X = require('ohsome2x'); 
import {Ohsome2XConfig} from 'ohsome2x/dist/config_types_interfaces';

// you can create this config using the command-line wizard, run: npx ohsome2x-cli
const config: Ohsome2XConfig = {
                ohsomeQuery: {...},
                source: {...},
                target: {...}
}                               

const ohsome2x = new Ohsome2X(config);

// This will return a Promise
ohsome2x.run().catch(console.log);
```

### Related

- [OhsomeHeX](https://ohsome.org/apps/osm-history-explorer) - The OSM History Explorer: Uses this library as backend
- [OhsomeAPI](https://api.ohsome.org) - WebAPI to query OSM History Data
- [OSHDB](https://github.com/GIScience/oshdb) - The OpenStreetMap History Database: Query OSM History Data with Java
- [ohsome.org](https://ohsome.org) - Get Information about all these technologies and more
- [heigit.org](https://heigit.org) - The Heidelberg Institute for Geoinformation Technology: The non-profit company behind all those useful tools.