mapcomplete/Logic/ExtraFunction.ts
2021-06-21 00:18:59 +02:00

192 lines
8.9 KiB
TypeScript

import {GeoOperations} from "./GeoOperations";
import Combine from "../UI/Base/Combine";
import {Relation} from "./Osm/ExtractRelations";
import State from "../State";
import {Utils} from "../Utils";
import BaseUIElement from "../UI/BaseUIElement";
import List from "../UI/Base/List";
import Title from "../UI/Base/Title";
export class ExtraFunction {
static readonly intro = new Combine([
new Title("Calculating tags with Javascript", 2),
"In some cases, it is useful to have some tags calculated based on other properties. Some useful tags are available by default (e.g. `lat`, `lon`, `_country`), as detailed above.",
"It is also possible to calculate your own tags - but this requires some javascript knowledge.",
"",
"Before proceeding, some warnings:",
new List([
"DO NOT DO THIS AS BEGINNER",
"**Only do this if all other techniques fail** This should _not_ be done to create a rendering effect, only to calculate a specific value",
"**THIS MIGHT BE DISABLED WITHOUT ANY NOTICE ON UNOFFICIAL THEMES** As unofficial themes might be loaded from the internet, this is the equivalent of injecting arbitrary code into the client. It'll be disabled if abuse occurs."
]),
"To enable this feature, add a field `calculatedTags` in the layer object, e.g.:",
"````",
"\"calculatedTags\": [",
" \"_someKey=javascript-expression\",",
" \"name=feat.properties.name ?? feat.properties.ref ?? feat.properties.operator\",",
" \"_distanceCloserThen3Km=feat.distanceTo( some_lon, some_lat) < 3 ? 'yes' : 'no'\" ",
" ]",
"````",
"",
"The above code will be executed for every feature in the layer. The feature is accessible as `feat` and is an amended geojson object:",
new List([
"`area` contains the surface area (in square meters) of the object",
"`lat` and `lon` contain the latitude and longitude"
]),
"Some advanced functions are available on **feat** as well:"
]).SetClass("flex-col").AsMarkdown();
private static readonly OverlapFunc = new ExtraFunction(
"overlapWith",
"Gives a list of features from the specified layer which this feature (partly) overlaps with. If the current feature is a point, all features that embed the point are given. The returned value is `{ feat: GeoJSONFeature, overlap: number}[]` where `overlap` is the overlapping surface are (in m²) for areas, the overlapping length (in meter) if the current feature is a line or `undefined` if the current feature is a point",
["...layerIds - one or more layer ids of the layer from which every feature is checked for overlap)"],
(params, feat) => {
return (...layerIds: string[]) => {
const result = []
for (const layerId of layerIds) {
const otherLayer = params.featuresPerLayer.get(layerId);
if (otherLayer === undefined) {
continue;
}
if (otherLayer.length === 0) {
continue;
}
result.push(...GeoOperations.calculateOverlap(feat, otherLayer));
}
return result;
}
}
)
private static readonly DistanceToFunc = new ExtraFunction(
"distanceTo",
"Calculates the distance between the feature and a specified point in kilometer. The input should either be a pair of coordinates, a geojson feature or the ID of an object",
["longitude", "latitude"],
(featuresPerLayer, feature) => {
return (arg0, lat) => {
if (typeof arg0 === "number") {
// Feature._lon and ._lat is conveniently place by one of the other metatags
return GeoOperations.distanceBetween([arg0, lat], [feature._lon, feature._lat]);
}
if (typeof arg0 === "string") {
// This is an identifier
const feature = State.state.allElements.ContainingFeatures.get(arg0);
if (feature === undefined) {
return undefined;
}
arg0 = feature;
}
// arg0 is probably a feature
return GeoOperations.distanceBetween(GeoOperations.centerpointCoordinates(arg0), [feature._lon, feature._lat])
}
}
)
private static readonly ClosestObjectFunc = new ExtraFunction(
"closest",
"Given either a list of geojson features or a single layer name, gives the single object which is nearest to the feature. In the case of ways/polygons, only the centerpoint is considered.",
["list of features"],
(params, feature) => {
return (features) => {
if (typeof features === "string") {
const name = features
features = params.featuresPerLayer.get(features)
if (features === undefined) {
var keys = Utils.NoNull(Array.from(params.featuresPerLayer.keys()));
if (keys.length > 0) {
throw `No features defined for ${name}. Defined layers are ${keys.join(", ")}`;
} else {
// This is the first pass over an external dataset
// Other data probably still has to load!
return undefined;
}
}
}
let closestFeature = undefined;
let closestDistance = undefined;
for (const otherFeature of features) {
if (otherFeature == feature || otherFeature.id == feature.id) {
continue; // We ignore self
}
let distance = undefined;
if (otherFeature._lon !== undefined && otherFeature._lat !== undefined) {
distance = GeoOperations.distanceBetween([otherFeature._lon, otherFeature._lat], [feature._lon, feature._lat]);
} else {
distance = GeoOperations.distanceBetween(
GeoOperations.centerpointCoordinates(otherFeature),
[feature._lon, feature._lat]
)
}
if (distance === undefined) {
throw "Undefined distance!"
}
if (closestFeature === undefined || distance < closestDistance) {
closestFeature = otherFeature
closestDistance = distance;
}
}
return closestFeature;
}
}
)
private static readonly Memberships = new ExtraFunction(
"memberships",
"Gives a list of `{role: string, relation: Relation}`-objects, containing all the relations that this feature is part of. " +
"\n\n" +
"For example: `_part_of_walking_routes=feat.memberships().map(r => r.relation.tags.name).join(';')`",
[],
(params, _) => {
return () => params.relations ?? [];
}
)
private static readonly allFuncs: ExtraFunction[] = [ExtraFunction.DistanceToFunc, ExtraFunction.OverlapFunc, ExtraFunction.ClosestObjectFunc, ExtraFunction.Memberships];
private readonly _name: string;
private readonly _args: string[];
private readonly _doc: string;
private readonly _f: (params: { featuresPerLayer: Map<string, any[]>, relations: { role: string, relation: Relation }[] }, feat: any) => any;
constructor(name: string, doc: string, args: string[], f: ((params: { featuresPerLayer: Map<string, any[]>, relations: { role: string, relation: Relation }[] }, feat: any) => any)) {
this._name = name;
this._doc = doc;
this._args = args;
this._f = f;
}
public static FullPatchFeature(featuresPerLayer: Map<string, any[]>, relations: { role: string, relation: Relation }[], feature) {
for (const func of ExtraFunction.allFuncs) {
func.PatchFeature(featuresPerLayer, relations, feature);
}
}
public static HelpText(): BaseUIElement {
const elems = []
for (const func of ExtraFunction.allFuncs) {
elems.push(new Title(func._name, 3),
func._doc,
new List(func._args, true))
}
return new Combine([
ExtraFunction.intro,
new List(ExtraFunction.allFuncs.map(func => func._name)),
...elems
]);
}
public PatchFeature(featuresPerLayer: Map<string, any[]>, relations: { role: string, relation: Relation }[], feature: any) {
feature[this._name] = this._f({featuresPerLayer: featuresPerLayer, relations: relations}, feature);
}
}