Here we experiment with sending messages between items on different pages.
let info = Object.fromEntries(new URLSearchParams(window.location.hash).entries()) export default { hello: "World!", info, parent: window.parent.name }
//observable.wiki.dbbs.co/assets/page/js-snippet-template/importjs.html
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We spent a couple of days at Microsoft Redmond working on widget-to-widget signalling with our custom meta-data driven WCF implementation (this was 10 years ago).
We kept on losing state due to frames blocking the origins. Later we had an opportunity to take this problem through with a Microsoft Engineer working at Google on the Dart Team. My hunch is, collaboration between programming language and web standards is needed. Ultimately a solution allows SQL functionality to be authored higher up in the web page stack.
Alas, when we presented our problem to .NET Developers Group at Microsoft Mountain View (about 150 people) very few could understand why we were trying to solve SaaS apps with web technologies.