An asynchronous start() problem

[theJiawen]

I notice that measureTool.start(initialPoints) method is asynchronous, which means that If I write code like this:

// say, there are 10 points in array `initialPoints`, with total length 1000m
measureTool.start(initialPoints);
console.log(measureTool.length);  // 0

I will not get what I want.

Can you make start() return a promise ?
like this:

measureTool.start(initialPoints).then ((tool)=>{ console.log(tool.length) })

[zhenyanghua]

Sorry for the delay. I don't want to introduce another polyfill for promise yet as this tool targets IE11 as well while I want to minimize the codebase and dependencies. At this moment, I should update the documentation to indicate the method is asynchronous. Because all measurement events are event-driven, event listeners must be used to guarantee obtaining the last result. You should be able to get the measurement by listening to the 'measure_change' event at this moment. I will leave this issue open and work out a solution. This will likely force the API signature to change, so it will be in the next major version.