Angular Binding Shape Files with Geo-spatial Data
The Ignite UI for Angular map component, the IgxShapeDataSource class loads geo-spatial data (points/locations, polylines, polygons) from shape files and converts it to a collection of IgxShapefileRecord objects.
Angular Binding Shape Files with Geo-spatial Data Example
The following table explains properties of the IgxShapeDataSource class for loading shape files.
| Propiedad | Tipo | Descripción |
|---|---|---|
shapefileSource |
cadena | Especifica el Uri de un archivo de forma (.shp) que contiene elementos de datos geoespaciales. |
databaseSource |
cadena | Especifica el Uri de un archivo de base de datos de formas (.dbf) que contiene una tabla de datos para elementos de datos geoespaciales. |
When both source properties are set to non-null values, then the IgxShapeDataSource object’s ImportAsync method is invoked which in return performs fetching and reading the shape files and finally doing the conversion. After this operation is complete, the IgxShapeDataSource is populated with IgxShapefileRecord objects and the ImportCompleted event is raised in order to notify about completed process of loading and converting geo-spatial data from shape files.
Loading Shapefiles
The following code creates an instance of the IgxShapeDataSource object for loading a shape file that contains locations of major cities in the world. It also demonstrates how to handle the ImportCompleted event as a prerequisite for binding data to the map component.
Binding Shapefiles
In the map component, Geographic Series are used for displaying geo-spatial data that is loaded from shape files. All types of Geographic Series have an ItemsSource property which can be bound to an array of objects. The IgxShapeDataSource is an example such array because it contains a list of IgxShapefileRecord objects.
The IgxShapefileRecord class provides properties for storing geo-spatial data, listed in the following table.
| Propiedad | Descripción |
|---|---|
Points |
Contiene todos los puntos en una forma geoespacial cargada desde un archivo de forma (.shp). Por ejemplo, el país de Japón en un archivo de forma se representaría como una lista de un objeto de lista de puntos, donde:
|
Fields |
Contiene una fila de datos del archivo de bases de datos de formas (.dbf) codificada por el nombre de una columna. Por ejemplo, un dato sobre el condado de Japón que incluye población, área, nombre de una capital, etc. |
Esta estructura de datos es adecuada para su uso en la mayoría de las series geográficas siempre que se les asigne las columnas de datos adecuadas.
Code Snippet
This code example assumes that shape files were loaded using the IgxShapeDataSource.
The following code binds IgxGeographicPolylineSeriesComponent in the map component to the IgxShapeDataSource and maps the Points property of all IgxShapefileRecord objects.
<div className="sampleRoot" >
<igx-geographic-map #map
width="700px"
height="500px"
zoomable="true" >
</igx-geographic-map>
</div>
<ng-template let-series="series" let-item="item" #template>
<div>
<span>
Airline: {{item.name}}
</span>
<br />
<span>
Length: {{item.distance}} miles
</span>
</div>
</ng-template>
import { AfterViewInit, Component, TemplateRef, ViewChild } from "@angular/core";
import { IgxShapeDataSource } from 'igniteui-angular-core';
import { IgxGeographicMapComponent } from 'igniteui-angular-maps';
import { IgxGeographicPolylineSeriesComponent } from 'igniteui-angular-maps';
@Component({
selector: "app-map-binding-shape-files",
styleUrls: ["./map-binding-shape-files.component.scss"],
templateUrl: "./map-binding-shape-files.component.html"
})
export class MapBindingShapefilePolylinesComponent implements AfterViewInit {
@ViewChild ("map")
public map: IgxGeographicMapComponent;
@ViewChild("template")
public tooltipTemplate: TemplateRef<object>;
constructor() { }
public ngAfterViewInit() {
// loading a shapefile with geographic polygons
const sds = new IgxShapeDataSource();
sds.importCompleted.subscribe(() => this.onDataLoaded(sds, ""));
sds.shapefileSource = "assets/Shapes/WorldCableRoutes.shp";
sds.databaseSource = "assets/Shapes/WorldCableRoutes.dbf";
sds.dataBind();
}
public onDataLoaded(sds: IgxShapeDataSource, e: any) {
const shapeRecords = sds.getPointData();
const geoPolylines: any[] = [];
// parsing shapefile data and creating geo-polygons
for (const record of shapeRecords) {
// using field/column names from .DBF file
const route = {
capacity: record.fieldValues["CapacityG"],
distance: record.fieldValues["DistanceKM"],
isActive: record.fieldValues["NotLive"] !== 0,
isOverLand: record.fieldValues["OverLand"] === 0,
name: record.fieldValues["Name"],
points: record.points,
service: record.fieldValues["InService"]
};
geoPolylines.push(route);
}
const geoSeries = new IgxGeographicPolylineSeriesComponent();
geoSeries.dataSource = geoPolylines;
geoSeries.shapeMemberPath = "points";
geoSeries.shapeFilterResolution = 0.0;
geoSeries.shapeStrokeThickness = 3;
geoSeries.shapeStroke = "rgb(82, 82, 82, 0.4)";
geoSeries.tooltipTemplate = this.tooltipTemplate;
this.map.series.add(geoSeries);
}
}
API References
FieldsIgxGeographicPolylineSeriesComponentImportCompletedItemsSourcePointsIgxShapeDataSource