Scalable Vector Graphics can be used in mapping to provide vector representations of itineraries without requiring an interactive mapping SDK. Alpaca.tech provides an output format of SVG data, allowing you to style and work with vector graphic representations of content you produce.
Alpaca provides resources for developers and designers to design a SVG representation of an itinerary.
The mapping service can output SVG representations of itinerary resources that are unstyled documents. Developers can incorporate the asset onto their website and then style the SVG elements as they prefer. SVG's can also be worked with using d3.js and other tools to style and present data as they wish.
In addition to the SVG itinerary documents, Alpaca provide some physical and cultural data to contextualise the itinerary SVG against features such as administrative boundies level 0 or 1 (country / regions).
When building applications, Alpaca offers a GraphQL API in order to obtain more information about itinerary features. For developers that are familiar with working with d3.js or alternative libraries, you may want to access the GeoJSON data directly to make alternative projections.
When making requests to either GraphQL or SVG resources hosted on Alpaca, you
must provide your accessToken.
SVG's are generated from the following base URL:
https://mapping.withalpaca.travel/v1/itinerary/XXX.svg?accessToken=YOUR_ACCESS_TOKEN
Substitute your itinerary/XXX with your itinerary ID and the accessToken with your access token.
To assist with stylising the SVG, the SVG output can have the presence of
certain data- attributes. The following table outlines some of the attributes
that may be included for certain features.
| Attribute | Description |
|---|---|
| class | The feature class, which corresponds to the same classes from GeoJSON (location_marker, directions_path etc) |
| data-id | Identifier for feature in Alpaca (can be used for GraphQL calls) |
| data-label | Label associated with the feature |
| data-location-num | The number associated with the location |
| data-mode | The mode of transport for the directions |
Along with your request, you can include the following query parameters to change the SVG export.
| Query Parameter | Description |
|---|---|
| bbox | Alternative bounding box, in 4 numeric values; "west,south,east,north" |
| pointAsCircle | Render points as an circle opposed to a path; "true" or "false" |
| markerLabelAsText | Render text elements for markers with label values; "true" or "false" |
| radius | Radius for the point; "1", "2"... |
| width, height | Viewport Canvas controls |
| lineStringProcessing | Line simplification and Bezier Spline operations to generalise detail |
To recreate a "generalised" route outline for geometry and smooth out line detail, the SVG can be customised using two operations:
- Simplify
- Bezier Spline
These operations can be used at the same time to both simplify the line then smooth out the detail using bezier splines.
Simplify is achieved using Douglas-Peucker algorithm, and can have a customised
tolerance (default is 0.85). You can splify a simplify operation via
lineStringProcessing=simplify, or by passing the tolerance via
lineStringProcessing=simplify_0.01.
Bezier Spline is achieved by lineStringProcessing=bezierSpline and can also be
customised via the resolution (default 10000) controlling the time in
milliseconds between points and sharpness (default 0.85) controlling how curvy
the path should be between splines. You can control the resolution and sharpness
through appending them to the string;
lineStringProcessing=bezierSpline_8000_0.6.
You can additionally support multiple stages of processing by seperating each
processing operation by a ,, such as
lineStringProcessing=simplify,bezierSpline.
Alpaca also provide simple boundary resources.
https://mapping.withalpaca.travel/v1/place/XXX.svg?accessToken=YOUR_ACCESS_TOKEN
Substitute the place/XXX with values as obtained from the following table:
You can also use an interactive map to identify the ID to include:
- Natural Earth Cultural (countries, regions and timezones)
- ABS 2021 Tourism Regions
- ABS Postal Boundaries
- ABS LGAs Boundaries
- ABS Electoral Boundaries
- ABS Suburb Boundaries
You can combine SVG data together into a single request leveraging the merge
query parameter. Provide multiple resources in the query param in order to draw
those SVG's into the same document body.
This can assist designers position the itinerary against other geographic features.
https://mapping.withalpaca.travel/v1/itinerary/XXX.svg?accessToken=YOUR_ACCESS_TOKEN&merge=place/naturalearth:iso-3166-1:au&bbox=109,-45,110,-9