m.reactive for reactive components proposal

[Ahmad-Helmy]

Description

m.reactive for reactive components

Wrape your component with m.reactive() and use m.redraw(component) from any place and it will just redraw this component and its children
eg:

var count = 0;

var Child = m.reactive({
    view: function () {
        return m("div", {}, [
            m("p", "Count: " + count),
            m(
                "button",
                {
                    onclick: (e) => {
                        e.redraw = false;
                        count++;
                        m.redraw(Child);
                    },
                },
                "increment"
            ),
        ]);
    },
});

var Parent = {
    view: function () {
        return m("div", {}, [
            m("h1", "Hello, Mithril! " + count),
            m(Child),
        ]);
    },
};

the child function will re-render, but parent function won't
NOTE:
you can use m.redraw() and it will work normally as expected just if you want re-render specific component add it as a param.

Motivation and Context

adding component level re render is improving performance

How Has This Been Tested?

until now manual tests

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project.
• I have added tests to cover my changes.
• All new and existing tests passed.
• My change requires a documentation update, and I've opened a pull request to update it already:
• I have read https://mithril.js.org/contributing.html.

[dead-claudia]

I'd prefer to see https://github.com/dead-claudia/mithril-helpers/blob/master/docs/self-sufficient.md integrated instead, as that does similar scoping without also forcing things to be global. I do appreciate the effort, though.

Also, your PR is missing tests. (My utility linked above was only hand-tested, so even if you were to do mine instead, you'd still have to roll tests for it.)