[Debian-science-sagemath] <DKIM> Re: widgetsnbextension situation

[Ximin Luo]

Julien Puydt:
> On 15/11/2016 02:51, Ximin Luo wrote:
> 
>> Perhaps we can use this information to regenerate extension.js without using webpack itself. Julien, have you seen anything approximating this approach before?
>>
> 
> Yes.
> 
> I would try using the compile-modules command from my package node-es6-module-transpiler -- and that might not even be necessary.
> 
> As I already mentioned (did I really?), webpack is mostly used to put together various chunks of javascript code and "compress" them so they're smaller for web use -- so there's a chance we can get away by not compressing anything and just installing the files as-is. That would mean just writing a debian/install file putting the un-modified source files at a right place so they find each other at runtime!
> 

I'm not sure if runtime-linking would be easy to make work. Do you have an example of this somewhere?

For now, I'm trying to write a python script to generate extension.js from "sources" and "sourcesContent" in extension.js.map. I'm about 80% of the way there...

For widgetsnbextension, webpack seems to do more sophisticated things than what you said. For a start, it wraps all of the component files with something like

function(module, exports, __webpack_require__) {
    [..internal javascript..]
}

then rewrites the internal javascript's calls to require(name) with __webpack_require__(i) where i is the index into webpack's own module list of modules, 56 of them for widgetsnbextension.

I have managed to recreate something similar to this rewriting in python, however webpack also does other rewriting, like this:

widgetsnbextension-1.2.6/widgetsnbextension/static$ ../../../ipywidgets/regen-webpack-source.py ./filelist ./module_list . > output; diff output extension.js

# output is what I can auto-generate so far; extension.js is what we're aiming for
--- output      2016-11-15 11:22:16.206545596 +0100
+++ extension.js        2016-07-14 22:31:07.000000000 +0200
@@ -865,9 +865,9 @@
 
 /***/ },
 /* 2 */
-/***/ function(module, exports) {
+/***/ function(module, exports, __webpack_require__) {
 
-       //     Underscore.js 1.8.3
+       var __WEBPACK_AMD_DEFINE_ARRAY__, __WEBPACK_AMD_DEFINE_RESULT__;//     Underscore.js 1.8.3
        //     http://underscorejs.org
        //     (c) 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
        //     Underscore may be freely distributed under the MIT license.
@@ -914,7 +914,7 @@
          // Export the Underscore object for **Node.js**, with
          // backwards-compatibility for the old `require()` API. If we're in
          // the browser, add `_` as a global object.
-         if (typeof exports !== 'undefined') {
+         if (true) {
            if (typeof module !== 'undefined' && module.exports) {
              exports = module.exports = _;
            }
@@ -2409,10 +2409,10 @@
          // popular enough to be bundled in a third party lib, but not be part of
          // an AMD load request. Those cases could generate an error when an
          // anonymous define() is called outside of a loader request.
-         if (typeof define === 'function' && define.amd) {
-           define('underscore', [], function() {
+         if (true) {
+           !(__WEBPACK_AMD_DEFINE_ARRAY__ = [], __WEBPACK_AMD_DEFINE_RESULT__ = function() {
              return _;
-           });
+           }.apply(exports, __WEBPACK_AMD_DEFINE_ARRAY__), __WEBPACK_AMD_DEFINE_RESULT__ !== undefined && (module.exports = __WEBPACK_AMD_DEFINE_RESULT__));
          }
        }.call(this));
 
@@ -2421,7 +2421,7 @@
 /* 3 */
[..]

etc etc. I'm not sure if this is feasible to recreate with regex in python, I would probably have to look for a Javascript AST parser and write rewrite rules for that. Or do you have an alternative suggestion?

After this is done, then there is the question of actually generating the "sourcesContent" files. I can see that "widgets.min.css" needs to be generated via other rules, but hopefully the *.js files can be copied directly from their sources...

X

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