Que Es Un Event Hub
Harold Yengo
An event can be triggered by the user action e.g. clicking the mouse button or tapping keyboard, or generated by APIs to represent the progress of an asynchronous task. It can also be triggered programmatically, such as by calling the HTMLElement.click() method of an element, or by defining the event, then sending it to a specified target using EventTarget.dispatchEvent().
Many DOM elements can be set up to accept (or "listen" for) these events, and execute code in response to process (or "handle") them. Event-handlers are usually connected (or "attached") to various HTML elements (such as , , , etc.) using EventTarget.addEventListener(), and this generally replaces using the old HTML event handler attributes. Further, when properly added, such handlers can also be disconnected if needed using removeEventListener().
A reference to the currently registered target for the event. This is the object to which the event is currently slated to be sent. It's possible this has been changed along the way through retargeting.
For this particular event, prevent all other listeners from being called. This includes listeners attached to the same element as well as those attached to elements that will be traversed later (during the capture phase, for instance).
Many DOM elements can be set up to accept (or \"listen\" for) these events, and execute code in response to process (or \"handle\") them. Event-handlers are usually connected (or \"attached\") to various HTML elements (such as , , , etc.) using EventTarget.addEventListener(), and this generally replaces using the old HTML event handler attributes. Further, when properly added, such handlers can also be disconnected if needed using removeEventListener().
The Event() constructor creates a new Event object. An event created in this way is called a synthetic event, as opposed to an event fired by the browser, and can be dispatched by a script.
Structured data is a standardized format for providing information about a page and classifying the page content. If you're new to structured data, you can learn more about how structured data works.
Here's an example of standard Event in JSON-LD. A standard event means that the event is happening at a physical location only and the event is happened as scheduled. You can also use Microdata or RDFa syntax.
Specify the timezone by including the UTC or GMT time offset. If the event starts at 7pm on September 5 in New York, the startDate value would be GMT/UTC-5 during standard time and GMT/UTC-4 during daylight savings time. During standard time, startDate value would be "2019-09-05T19:00:00-05:00" or "2019-09-05T19:00:00-04:00" respectively. If no timezone is provided, Google uses the timezone of the event's location as specified in location. For online events, the timezone is required, since there is no location information that Google can use to understand when the event starts.
You must include the required properties for your content to be eligible for display in enhanced search results. You can also include the recommended properties to add more information about your content, which could provide a better user experience.
The URL of the online event, where people can join. This property is required if your event is happening online. If the URL to join the event isn't available until after registering for the event, provide the registration URL where people can take the next steps to join your event.
The start date and start time of the event in ISO-8601 format. Add both the date and time so users can find events that fit into their schedule. For online events, you must specify the timezone by including the UTC or GMT time offset.
The end date and end time of the event in ISO-8601 format. Use the same format as startDate. Add both the date and time so users can find events that fit into their schedule. For online events, you must specify the timezone by including the UTC or GMT time offset.
Indicates whether the event occurs online, offline at a physical location, or a mix of both online and offline. If you don't include this property, Google understands the event mode to be OfflineEventAttendanceMode, which means Google understands that the event is happening at a physical location. Use one of the following values:
The status of the event. If you don't use this field, Google understands the eventStatus to be EventScheduled. Here are the supported values. You can use multiple statuses, if applicable (for example, if an event was both rescheduled and moved online).
The event has been postponed to a later date, but the date isn't known yet. Keep the original date in the startDate of the event until you know when the event will take place. Once you know the new date information, change the eventStatus to EventRescheduled and update the startDate and endDate with the new date information.
The event has been rescheduled to a later date. Update the startDate and endDate with the relevant new dates. Optionally, you can also mark the eventStatus field as rescheduled and add the previousStartDate.
The person or organization that is hosting the event. This is especially important for online events, where there isn't any venue information. If you include organizer, we encourage you to add the following properties:
The previously scheduled start date for the event if an event has been rescheduled. If you add previousStartDate, you must also add the eventStatus property and set the eventStatus to EventRescheduled. Don't use other event statuses.
For rescheduled events, the startDate property must only be used for the newly scheduled start date. In the (rare) case of an event that has been postponed and rescheduled multiple times, this field may be repeated.
Search Console is a tool that helps you monitor how your pages perform in Google Search. You don't have to sign up for Search Console to be included in Google Search results, but it can help you understand and improve how Google sees your site. We recommend checking Search Console in the following cases:
- After deploying structured data for the first time
- After releasing new templates or updating your code
- Analyzing traffic periodically
If your event isn't appearing in the event experience on Google or if you've received a manual action for Spammy Structured Markup in Search Console, resolve the most common issues and review our guidelines. If you're still experiencing issues, check the Event FAQ or post in the Google Search Central forum.
error What caused the issue: Google doesn't understand the values provided for the eventLocation, addressLocality, or addressRegion properties. Google tries to match the location information to a physical location, and the location provided is either missing or incorrect.
error What caused the issue: The time or date is incorrect. Common errors include not offsetting for the time zone or specifying an incorrect start time (for example, midnight as a start time).
Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 4.0 License, and code samples are licensed under the Apache 2.0 License. For details, see the Google Developers Site Policies. Java is a registered trademark of Oracle and/or its affiliates.
We can query an application's state to find out the current state of the world, and this answers many questions. However there are times when we don't just want to see where we are, we also want to know how we got there.
Event Sourcing ensures that all changes to application state are stored as a sequence of events. Not just can we query these events, we can also use the event log to reconstruct past states, and as a foundation to automatically adjust the state to cope with retroactive changes.
The fundamental idea of Event Sourcing is that of ensuring every change to the state of an application is captured in an event object, and that these event objects are themselves stored in the sequence they were applied for the same lifetime as the application state itself.
Let's consider a simple example to do with shipping notifications. In this example we have many ships on the high seas, and we need to know where they are. A simple way to do this is to have a tracking application with methods to allow us to tell when a ship arrives or leaves at a port.
Looking at just the processing, this is just an unnecessary level of indirection. The interesting difference is when we look at what persists in the application after a few changes. Let's imagine some simple changes:
With Event Sourcing we also capture each event. If we are using a persistent store the events will be persisted just the same as the ship objects are. I find it useful to say that we are persisting two different things an application state and an event log.
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