bug: [#192] Fixed broken map event unmounting #193
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When unmounting a specific map event handler (`map.off(eventType, func)`), the exact same mounting function (`map.on(eventType, func)`) has to be used. Otherwise the map unmounting doesn't know how which function should be removed, and nothing happens (resulting in more and more duplicate handlers for the same event). See https://leafletjs.com/reference.html#evented-off By using a custom function on the `map.on()` (which in turn *might* call the correct `props[handler]`), the `props[handler]` is actually never used as event handler. Meaning that the `map.off()`, in the current setup, will never work. By making sure that the `map.on()` and `map.off()` use the same function, the unmounting works as expected and old event handlers are removed.
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Closes #192
To correctly unmount a event handler the
map.on()andmap.off()have to use the exact same props, otherwise themap.off()cannot correctly identify which handler to unmount, resulting in multiple (read duplicate) event handlers for the same event. See https://leafletjs.com/reference.html#evented-off for more informationBy using a custom function on the
map.on()(which in turn might call the correctprops[handler]), theprops[handler]is actually never used as event handler. Meaning that themap.off(), in the current setup, will never work.By making sure that the
map.on()andmap.off()use the same function, the unmounting works as expected and old event handlers are removed.I couldn't find a reason why this "function checking its own type, and then maybe calling the correct
props[handler]" behaviour was implemented. If someone can tell me why (and preferably a bug report that shows an actual bug), i can look into a solution that uses the old setup.