overpass

README

go-overpass

go-overpass is a Go library for accessing the Overpass API

Documentation:

Documentation

Overview

Package overpass provides a client for using the Overpass API.

Usage:

import "github.com/serjvanilla/go-overpass"

Construct a new client, then use Query method on the client to receive result for your OverpassQL queries.

client := overpass.New()

//Retrieve relation with all its members, recursively.
result, _ := client.Query("[out:json];relation(1673881);>>;out body;")
//Take a note that you should use "[out:json]" in your query for correct work.

Default client uses overpass-api.de endpoint, but you can choose another with NewWithSettings method.

client := overpass.NewWithSettings("http://api.openstreetmap.fr/oapi/interpreter/", 1, http.DefaultClient)

You also can use default client directly by calling Query independently.

result, _ := overpass.Query("[out:json];relation(1673881);>>;out body;")

Rate limiting

Library respects servers rate limits and will not perform more than one request simultaneously with default client. With custom client you are able to adjust that value.

Index

• Variables
• type Box
• type Client
  • func New() Client
  • func NewWithSettings(apiEndpoint string, maxParallel int, httpClient HTTPClient) Client
  • func (c *Client) Query(query string) (Result, error)
• type ElementType
• type HTTPClient
• type Meta
• type Node
• type Point
• type Relation
• type RelationMember
• type Result
  • func Query(query string) (Result, error)
• type ServerError
  • func (e *ServerError) Error() string
• type Way

Variables

var DefaultClient = New()

Types

type Box

type Box struct {
	Min, Max Point
}

type Client

type Client struct {
	// contains filtered or unexported fields
}

A Client manages communication with the Overpass API.

func New

func New() Client

New returns Client instance with default overpass-api.de endpoint.

func NewWithSettings

func NewWithSettings(
	apiEndpoint string,
	maxParallel int,
	httpClient HTTPClient,
) Client

NewWithSettings returns Client with custom settings.

func (*Client) Query

func (c *Client) Query(query string) (Result, error)

Query send request to OverpassAPI with provided querystring.

type ElementType

type ElementType string

ElementType represents possible types for Overpass response elements.

const (
	ElementTypeNode     ElementType = "node"
	ElementTypeWay      ElementType = "way"
	ElementTypeRelation ElementType = "relation"
)

Possible values are node, way and relation.

type HTTPClient

type HTTPClient interface {
	PostForm(url string, data url.Values) (*http.Response, error)
}

type Meta

type Meta struct {
	ID        int64
	Timestamp *time.Time
	Version   int64
	Changeset int64
	User      string
	UID       int64
	Tags      map[string]string
}

Meta contains fields common for all OSM types.

type Node

type Node struct {
	Meta
	Lat float64
	Lon float64
}

Node represents OSM node type.

type Point

type Point struct {
	Lat, Lon float64
}

type Relation

type Relation struct {
	Meta
	Members []RelationMember
	Bounds  *Box
}

Relation represents OSM relation type.

type RelationMember

type RelationMember struct {
	Type     ElementType
	Node     *Node
	Way      *Way
	Relation *Relation
	Role     string
}

RelationMember represents OSM relation member type.

type Result

type Result struct {
	Timestamp time.Time
	Count     int
	Nodes     map[int64]*Node
	Ways      map[int64]*Way
	Relations map[int64]*Relation
}

Result returned by Query and contains parsed result of Overpass query.

func Query

func Query(query string) (Result, error)

Query runs query with default client.

type ServerError

type ServerError struct {
	StatusCode int
	Body       []byte
}

func (*ServerError) Error

func (e *ServerError) Error() string

type Way

type Way struct {
	Meta
	Nodes    []*Node
	Bounds   *Box
	Geometry []Point
}

Way represents OSM way type.