BSON Decoding of Binary Objects

[DLu]

roslibjs component of RobotWebTools/rosbridge_suite#169

Pairs with RobotWebTools/rosbridge_suite#190

Current problem: BSON is a huge dependency.

Original file sizes

-rw-rw-r-- 1 dlu dlu  65K Jul 10 17:08 roslib.js
-rw-rw-r-- 1 dlu dlu  27K Jul 10 17:09 roslib.min.js

New File Sizes with this PR

-rw-rw-r-- 1 dlu dlu 275K Jul 10 17:09 roslib.js
-rw-rw-r-- 1 dlu dlu 104K Jul 10 17:09 roslib.min.js

Is that a problem? Is there a better way?

[DLu]

Also, do you need to check in the updated built files? I didn't and I'm trying to tell if that's why the tests are failing.

[rctoris]

You don't need to rebuild in on a PR. The tests seem to be failing because it can't load Blob. You should do a check to see if Blob is actually available https://github.com/RobotWebTools/roslibjs/pull/185/files#diff-49dcdae7a46fbde852bf41066508c9f7R111

[DLu]

That was easier than I originally thought. I was trying to find the correct dependency to ensure Blob was defined. I think I did it correctly this time. Javascript is a weird language.

The original question about the file size remains.

[rctoris]

Is this pulling in all of bson into the build file? Can we make it a shim like EventEmitter2 and such? I'm less familiar with the idea but I think this is the way to go.

https://github.com/RobotWebTools/roslibjs/tree/develop/src/util/shim
https://github.com/RobotWebTools/roslibjs/blob/develop/package.json#L38

[DLu]

Ok, I've gotten it to the point where it works and builds. It will work correctly if you include the [https://raw.githubusercontent.com/mongodb/js-bson/master/browser_build/bson.js](bson header) and print an error message if you try to decode a bson message without the header.

However, I don't think this is the right way to do it. I tried to make a shim, but had problems getting it to build with grunt AND work in the browser.

[rctoris]

Since it is an optional feature we can make it optional like ColladaLoader is in ros3djs

[megawac]

Are we not going to move this to an extension adapter, so the user could include if desired, to avoid the file size increase

require('roslib/adapters/bson')