Multi-value support for GM_getValues, GM_setValues, GM_deleteValues?

[tophf]

Maybe something like this?

• GM_getValues(['foo', 'bar']) -> {foo: 1, bar: 2} or {foo: 1} if bar is missing
• GM_getValues({foo: 1, bar: 2}) -> providing the default values.
• GM_getValues() or GM_getValues(null) or GM_getValues(undefined) -> read the entire storage

---

• GM_setValues({foo: 1, bar: 2})
• GM_deleteValues(['foo', 'bar'])

Ideally I'd like Violentmonkey/Tampermonkey to avoid preloading all storage data at script start when the script doesn't ask for the legacy GM_xxxValue, in which case multi-value support becomes important because of the overhead to process each value individually. When GM.xxxValue functions are implemented as a native asynchronous call it makes sense from a performance viewpoint to allow specifying multiple values in one call, just like it's done in chrome.storage API.

[derjanb]

Makes sense. I'll add support for this in the next BETA version.

[cyfung1031]

Could there be something "Proxy" ? ( the usage is like localStorage )
So developers do not need to think too much about sync the values along tabs.
and don't need getValue and setValue

Option 1

// only one argument. object. the value is the default value if not exist (so this can make sure there is always a default value)
const gmValues = GM_values({
foo: 1,
bar: 2
});

// gmValues is a Proxy
// the values are obtained at each proxy's get

console.log(await gmValues.foo) // 1
gmValues.foo = 3
console.log(await gmValues.foo) // 3

Option 2

// only one argument. object. the value is the default value if not exist (so this can make sure there is always a default value)
const gmValues = await GM.values({
foo: 1,
bar: 2
});
// values are all cached in gmValues.

// gmValues is a Proxy. All values inside will have GM_addEvenListener. 
// the values will be automatically updated, so getter just read the stored cache value.

console.log(gmValues.foo) // 1 (just the cache)
gmValues.foo = 3
console.log(gmValues.foo) // 3 (the GM.setValue might be not completed at this time, but the setter updated the cache value already)

// if it is changed externally, the gmValues.foo will be also updated.

[tophf]

With proxy you can't await the result of setting the value. Either way, it's not related to the idea in this issue, so you should open a new one.

[erosman]

If I may add a word, FM introduced multi-value GM storage option in erosman/support#545
Initially, using a new API but changing to an option for the existing API, which mimics the browser.storage.local.get().

[tophf]

I thought about extending the existing singular functions with the new syntax, but I decided it would encourage authors to use it directly without first checking for typeof GM.getValues === 'function'.

[derjanb]

Fixed at 5.3.6207 (crx|xpi in review)

I've decided against overloading the old API methods, because it would be difficult to detect whether multi-values are supported or not.