Method trackQuery

src/core/runtime/reactivity.js:268–274

* Track a DOM query as a dependency. Re-evaluates when any DOM * change occurs within root or its descendants. * @param {Element|Document} root - the element querySelectorAll runs on (e.g. #myTable in `<:checked/> in #myTable`)

(root)

     * @param {Element|Document} root - the element querySelectorAll runs on (e.g. #myTable in `<:checked/> in #myTable`)
     */
    trackQuery(root) {
        if (!this._currentEffect) return;
        root = root || document;
        var key = "query:" + this._getObjectState(root).id;
        this._currentEffect.dependencies.set(key,
            { type: "query", root: root });
    }

    /**
     * Notify that a global variable was written.