Trend Indicator is a chrome extension that displays a value and the current trend for that value on a BrowserAction! It's useful for things like temperature, inbox level, or anything else with a value < 1000. The indicator is updated in real time via a HTML5 EventStream.
The extension must be pointed at a server that serves up a HTML5 EventSource and a static version of the last event served.
Click on the icon and enter the URL in the obvous box.
An example server that generates random data can be found in eventsource.go.
The server must provide an HTML5 EventSource and a /last endpoint.
For example:
- https://myhost/events/ - this is the HTML5 EventSource
- https://myhost/events/last - this should serve up the content of the last message served for bootstrapping.
The only thing that's important in the URL is the /last suffix. /events isn't needed.
An appropriate Access-Control-Allow-Origin header must be sent, or Chrome will refuse to process the data.
For example, allow all origins:
Access-Control-Allow-Origin: *
Messages should have EventSource type message and be the JSON representation
of this go struct:
type pushMessage struct {
// The value of the indicator.
Value string `json:"value"`
// The timestamp of when the value was generated.
Timestamp int64 `json:"timestamp"`
// Offset into trend array.
Trend int `json:"trend"`
}For example:
{value: "204", timestamp: 1552878938, trend: 4}- (nothing)
- ↑↑ (up fast)
- ↑ (up)
- ↗ (up slowly)
- → (steady)
- ↘ (down slowly)
- ↓ (down)
- ↓↓ (down fast)
- ❓ (unknown)
⚠️ (problem)
- Why only numbers < 1000? Because otherwise they're too small to read.
This is not an official Google project.