A Wiki Page has a journal of actions that have been completed.
The journal lists each Action that contributed to the page being what and where it is now. The journal records the History of how the page was made and where it has traveled.
The `addToJournal` function is called when the origin server response that the network operation is complete.
When the journal is accurate it can be replayed to recreate every version of the page through its history.
When the journal identifies sites from which it has been copied (forked) those sites will be added to the Neighborhood upon display.
See our glossary for more Names of Things
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The page journal is now accessed via a frame in the page that surrounds the frame:
We send a message to the Frame asking it to send us info about the page surrounding it. mdn 
window.addEventListener("message", handler) let message = { action:"sendFrameContext" } window.parent.postMessage(message, "*")
We stop listening then process the data we got.
function handler ({data}) { if (data.action == "frameContext") { window.removeEventListener("message", handler) const {slug, item, page} = data show(page) } }
The page we show is the page on the screen which might be a ghost, maybe retrieved from history.
function show (page) { let actions = page.journal.map(item => [ item.type, item.id ]) let html = `<pre>${actions.join("\n")}</pre>` output.innerHTML = html }
Note: page.journal.[…] – the information stored must support path playback and path visualization.
We change the show function to see actions as objects. An action, i.e. a page.journal.item, has an ID, a text and a type.
Note: item.text seems to be something special.
Actions: [⇒ Updating Events and Causal Dependence]
//wiki.ralfbarkow.ch/assets/pages/snippet-template/basicjs.html?snippet-template HEIGHT 200
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See Array.prototype.map() mdn
Element list?
item.text: Object.prototype.toString() mdn
Event-Driven System Domain
In an event-driven system, domain Events are published to a *journal*. page – Modelling Reactive Systems with Event Storming and Domain-Driven Design
See Event Sourcing
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