Harmony in node-wekbit?

[mblinsitu]

I would like to use the Harmony features of V8 in node-webkit.
I can do that with node alone using "node --harmony" but this option is not recognized by node-webkit.

I am particularly interested in Proxy and WeakMap. As explained in issue #296, the node-proxy module that emulates Proxy does not work out of the box with node-webkit on the Mac because of 32- vs. 64-bit issues.

More generally, it would be useful to expose the V8 engine options to node-webkit since these are available from both node and webkit (e.g. in Chrome using the about:flags URL).

[Mithgol]

It also could make some things easier if these options were supported as node-webkit's package.json fields in addition to (maybe even instead of) the command line's switches. (After all, package.json is where we define the application's properties and required features.)

[mblinsitu]

I agree. It would be much better to configure these through package.json rather than with command-line arguments.
Maybe with a "V8-options" field? Ideally, all the options listed with node --v8-options should be available.

[Mithgol]

The above idea is specified in the #307 issue now, so this issue (#298) may be used exclusively for tracking the future Harmony command line features.

[rogerwang]

Chromium has a command line flag js-flags to set this. Since we added the support for Chromium args in manifest with #307 , this issue is also fixed now. You can use harmony-proxies in js-flags.

[zhchbin]

Hi @rogerwang . It seems that currently my implement of the chromium-args can't work in this situation. I test it on WIN . Sorry for the miss. Do you have any idea about this?

[rogerwang]

it doesn't handle key=value case. I'll have a fix soon.

[rogerwang]

@zhchbin can you review my changes to see whether it's ok for you?

[Mithgol]

Would you extend the corresponding wiki article with an example of js-flags in chromium-args, maybe with an example of Harmony flags specifically? That could save the users from reading a manual on chromium command line arguments for this (relatively common) case.

[rogerwang]

@Mithgol done and thanks for the suggestion. https://github.com/rogerwang/node-webkit/wiki/Manifest-format/_compare/fc6d2c8%5E...fc6d2c8

I'm not sure why the syntax highlighting is not working...

[zhchbin]

Hi, @rogerwang, thanks for fix my implement, key=value case is missed out of ignorance. However, On WIN, there will be a compile error because CommandLine::StringType will be std::wstring after your change.

Edit: and it break the use case like: "chromium-args" : "disable-accelerated-video". Now it should be "chromium-args" : "--disable-accelerated-video". However, I think your choice would be better.

[Mithgol]

The "chromium-args": "--js-flags=--harmony-proxies" example is good and may suffice.

Though I still wonder if a newbie would need a more complex example involving escaped quotes and a separator between two different V8-related arguments, such as --harmony_proxies and --harmony_collections:

"chromium-args": "--js-flags=\"--harmony-proxies --harmony_collections\""

I haven't made any decision about its necessity (otherwise I would have replaced the example in the wiki already).

[zhchbin]

@Mithgol Sorry to tell you that, currently my implement doesn't meet your case:

"chromium-args": "--js-flags=\"--harmony-proxies --harmony_collections\""

The correct one should be:

"chromium-args": "--js-flags=--harmony-proxies --js-flags=--harmony_collections"

I will update the wiki...

Update: In the previous use case, only the last one js-flags work.

[pauliusuza]

I'm trying to use this on v4.0:
"chromium-args": "--js-flags=--harmony-proxies --js-flags=--harmony_collections --js-flags=--harmony_modules --js-flags=--harmony_scoping"

but I keep getting errors in my app.html:
Uncaught ReferenceError: WeakMap is not defined

any ideas?

[rogerwang]

try to add harmony-weakmaps to the js-flags

[pauliusuza]

Tried it, no luck. Does it work for anyone else?

[edit: using single flag --js-flags=--harmony solves the issue. thanks @zhchbin!]

[zhchbin]

@pauliusuza Please have a try by using: "chromium-args": "--js-flags=--harmony" This will enable all.

@rogerwang It seems that using space to separate two option in our use case does have some problems. Can we change it to use another? For example: ; And my previous comment is wrong because I just test whether the second option work. In the following use case, only the last work..
"chromium-args": "--js-flags=--harmony-proxies --js-flags=--harmony_collections --js-flags=--harmony_modules --js-flags=--harmony_scoping"

[owenc4a4]

Can this be the solution? fc297de352156fedaa7bacd145e8b078a006c535
using '|' to separate the value.

[zhchbin]

Hi @owenc4a4 , maybe wrong, your commit has nothing to do with the case in my comment... I will fix it as my previous description and update the test case and wiki soon.

[rogerwang]

Why we cannot use whitespace as the separator?

[zhchbin]

@rogerwang in the following case:
"chromium-args": "--js-flags=--harmony-proxies --js-flags=--harmony_collections",
only --js-flags=--harmony_collections work, the first one will be overrode. Change to other separator, like ; can fix this, but it will change the api, this is why am I waiting for your opinion.

The new usage of this api will become
"chromium-args": "--js-flags=--harmony-proxies --harmony_collections;--disable-accelerated-video"

[rogerwang]

I prefer not to use semicolons. Can multiple js-flags be quoted with single quote (') ?

[zhchbin]

I get what you are concerned about. However, if multiple js-flags be quoted with single quote ', there still have some spaces between every two options within single quote, to deal with this I should change this simple code to more complicated one.

[rogerwang]

I think there could be some code for this kind of command line parsing in Chromium code which we could utilize.

[Mithgol]

Alternatively, you may make these flags separate by introducing some "js-flags": "..." property in the manifest (with space-separated flags inside the property's value) that would be combined with chromium-args internally (inside the node-webkit engine) and then applied.

That would be easier for the people composing their manifests (I mean, not to mistype space for a semicolon out of habit, or a double quote instead of single, etc.).

Some visual separation between the flags of different nature (where chromium-args affect only Chromium while js-flags affect all JavaScript, including Node.js) feels somewhat natural.

[zhchbin]

@rogerwang will change the code as your description. Reopen to track it.

[rogerwang]

I think @Mithgol 's idea is great. You can add that field in manifest.

[zhchbin]

Got it, thanks @Mithgol 's idea.

[Mithgol]

Thanks for accepting my suggestion.

[zhchbin]

Wiki of js-flags and chromium-args updated: Link