Fixes checked property being reset on render

[WorldSEnder]

If the value is uncontrolled, do not touch it. Only if it is explicitly given (controlled) set it with every render.

A boolean attribute can have two states: it can exist or be omitted (true and false).
A boolean property can have three states in vdom: it can be explicitly assigned true, explicitly assigned false or it can be left uncontrolled. The last has been missing and the buggy behaviour assumes the last is synonymous with "explicitly false".

Marked as a breaking change, because the API exposed by vdom changes slightly. This is not technically necessary for the PR, but it should serve as a reminder for anybody using the method that there was something subtly wrong with it, as it also assumed a default-unchecked which is not true.

- pub fn VTag::checked(&self) -> bool;
+ pub fn VTag::checked(&self) -> Option<bool>;
+ pub fn VTag::preserve_checked(&mut self);

Description

Fixes #2875. I will add tests when I have time in the coming days.

Checklist

• I have reviewed my own code
• I have added tests

[github-actions]

Visit the preview URL for this PR (updated for commit b823556):

https://yew-rs-api--pr2907-fix-checkbox-3r5hjhns.web.app

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[github-actions]

Benchmark - SSR

Yew Master

Benchmark	Round	Min (ms)	Max (ms)	Mean (ms)	Standard Deviation
Baseline	10	345.847	347.271	346.320	0.410
Hello World	10	622.304	626.181	623.166	1.155
Function Router	10	2192.283	2208.406	2199.579	4.814
Concurrent Task	10	1007.990	1009.628	1008.805	0.578

Pull Request

Benchmark	Round	Min (ms)	Max (ms)	Mean (ms)	Standard Deviation
Baseline	10	307.364	312.694	308.912	2.011
Hello World	10	603.014	605.245	603.820	0.614
Function Router	10	2190.796	2246.407	2214.240	14.082
Concurrent Task	10	1008.384	1009.677	1008.899	0.383

[github-actions]

Size Comparison

examples	master (KB)	pull request (KB)	diff (KB)	diff (%)
async_clock	106.217	106.233	+0.017	+0.016%
boids	170.378	170.401	+0.023	+0.014%
communication_child_to_parent	90.110	90.125	+0.015	+0.016%
communication_grandchild_with_grandparent	104.910	104.962	+0.052	+0.049%
communication_grandparent_to_grandchild	100.767	100.826	+0.060	+0.059%
communication_parent_to_child	87.214	87.232	+0.019	+0.021%
contexts	107.382	107.444	+0.062	+0.058%
counter	85.128	85.148	+0.021	+0.024%
counter_functional	85.601	85.619	+0.019	+0.022%
dyn_create_destroy_apps	87.963	87.982	+0.020	+0.022%
file_upload	99.700	99.717	+0.017	+0.017%
function_memory_game	162.823	162.849	+0.025	+0.016%
function_router	347.237	347.283	+0.046	+0.013%
function_todomvc	157.660	157.688	+0.028	+0.018%
futures	222.020	222.036	+0.017	+0.007%
game_of_life	104.622	104.644	+0.021	+0.021%
immutable	181.201	181.219	+0.018	+0.010%
inner_html	81.991	82.011	+0.020	+0.024%
js_callback	110.913	110.976	+0.062	+0.056%
keyed_list	195.485	195.503	+0.018	+0.009%
mount_point	84.739	84.758	+0.019	+0.022%
nested_list	111.664	111.725	+0.061	+0.054%
node_refs	92.611	92.632	+0.021	+0.022%
password_strength	1546.993	1547.012	+0.019	+0.001%
portals	95.977	96.043	+0.066	+0.069%
router	317.025	317.094	+0.068	+0.022%
simple_ssr	151.692	151.759	+0.066	+0.044%
ssr_router	392.376	392.445	+0.069	+0.018%
suspense	108.660	108.722	+0.062	+0.057%
timer	87.993	88.013	+0.020	+0.022%
todomvc	138.957	138.977	+0.020	+0.014%
two_apps	85.794	85.813	+0.020	+0.023%
web_worker_fib	152.043	152.066	+0.023	+0.015%
webgl	84.434	84.450	+0.017	+0.020%

✅ None of the examples has changed their size significantly.

[hamza1311]

Looks good to me