mapbox/mapbox-gl-js

Allow image source without image/coordinates

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#10,802 opened on Jun 24, 2021

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 (2 comments) (0 reactions) (1 assignee)JavaScript (10,532 stars) (2,203 forks)batch import
good first issue

Description

Motivation

I often use this pattern for GeoJSON sources:

  1. addSource('mysource', { type: 'geojson', data: { type:'FeatureCollection', features: [] }});
  2. addLayer({ id: 'mylayer', source: 'mysource' })
  3. Now fetch the actual data, manipulate it, and call setData() to set it.

I do this because:

  • I need to fetch the data asynchronously (but I don't want to hold up all my other init)
  • I want the layer to be in a predictable place in the style (which I wouldn't get if I waited for the data to load before creating the source and the layer).

This doesn't work with the Image type because you have to provide some kind of actual data.

It would be more flexible thus if the image type didn't require data, like the geojson type.

Contributor guide

Tech stack
javascript
Domain
frontend
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
blocked
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
JavaScriptMapbox GL JS source internals
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
25
Research direction
Investigate the image source implementation in mapbox gl js, likely in src/source/image source.js. Understand how the source currently requires image data and coordinates. Propose a change to allow constructing an image source without immediate data, similar to how geojson sources work. Check related discussions and test files for guidance.