 | If you are using FLOW version 1.18 or earlier, please, refer to the articles About Widgets [v 1.18 and earlier] and About Sinks [v 1.18 and earlier] for relevant information. |
FLOW offers a wide range of options for filtering trajectories of interest based on specific use cases, using a combination of operators. Widgets and sinks help visualize or process these filtered trajectories and the events associated with them.
Using Widgets and Sinks
Both widgets and sinks are attached to operators on the Canvas by drag and drop. In the example below, the Statistical value widget is attached to the operator filtering objects with a stationary duration parameter in the range of 0 - 30 seconds. The same way we can attach to it any of the available widgets, such as Distribution, Value, and others, or available sinks. Also we may attach these widgets and sinks to multiple, different operators on the Canvas.
Widgets
Widgets aggregate, summarize and present trajectory data in FLOW. They allow different types of data presentation on the Dashboard, where they are instantiated automatically when placed on the Canvas. All widget data is accessible through the API.
Available Widgets
The following list shows the available widgets in FLOW, including links to separate articles where each is described in more detail:
Table (replaced by Trajectory Events)
OD Matrix (replaced by Movement Set Statistics)
Events (Trajectory Events and Near Miss Events)
Some special widgets are available on the Dashboard, specifically:
Movement Set Statistics, combining inputs from different analytics
Expression Widgets, enabling scriptable behavior
Sinks
Sinks extend the list of available widgets with more options, specializing in integration with external systems. Unlike widgets, sinks do not present data on the Dashboard, they are only used exclusively to pass trajectory data outside of FLOW for further processing or storage. Sinks are grouped based on the type of interface they use to send the data.
Available Sinks
Follows a list of available sinks in FLOW. These are described in more detail in the article Rest, UDP and File Sinks.
REST Sinks:
Raw trajectories
UDP Sinks:
Category count sink
Zone sink
Object list
File Sinks:
Trajectory file sink
Configurability and Options
Each widget and sink type has a range of specific configuration options available in their settings. Widgets offer different visualization options, such as coloring, charts, pie charts, and more. General options are described below, some specifics may be found in the respective articles.
Attribute
The Attribute (also referred to as Operator Attribute) is the basic configuration option available for each widget or sink. It defines which specific output data from the connected operator will be used for further processing, visualization, or export. The selected attribute determines what type of data the widget or sink will work with, such as speed, object category, occupancy, or other operator-generated metrics.
The list of available attributes depends on the operator and the type of widget or sink being used. Specific attribute options for each widget and sink are described in their respective articles.
Time Modes
All widgets offer various time mode options, allowing you to define how data is aggregated and displayed over time. Additionally, when exporting time data, you can configure the format and handling of timestamps. Exported time data may further be post-processed.
For more details on time modes and time configuration, refer to the article Time in FLOW.
Snapshotting Policy
Snapshotting Policy defines how and when data snapshots are created for widgets and sinks in FLOW. It controls the timing of data capture, with two main options:
On Value Change – Creates a snapshot whenever the value changes.
Aligned Fixed Period – Creates snapshots at predefined, regular intervals, regardless of whether the value has changed.
Tags
Tags allow you to add custom labels to widgets and sinks, helping to organize and identify different outputs within your FLOW project. For more details on how to configure and use tags, refer to the article Tags in FLOW.
History (Time Series Visualization)
Some widget types—specifically Value, Statistical Value, and Distribution—allow you to visualize a history of their values over time in customizable charts.
To select the time mode you may choose:
Sliding window — a moving time interval relative to the current moment specifying its length or offset.
From → To — a fixed time interval.
When time series visualization is enabled, a chart appears below the widget’s numerical value. The chart only shows data which the widget has collected.
Coloring
You can assign different colors to value ranges. If the widget’s value falls within a given range, it will be automatically colored according to your settings.
Widgets can be resized to display more or less data points, allowing for better readability of the chart.
Summary
Widgets and sinks are key tools in FLOW for presenting collected data and sending it to external systems. This article includes the overview of widgets and sinks and provides links to the respective articles, covering their configuration, use cases, and visualization options.
All widgets and sinks are available through the FLOW Public API (REST, UDP, webhooks) for easy integration and data processing outside of FLOW. Learn more in Introduction to FLOW Public API.
If you need help or have questions, feel free to contact us — we’re happy to assist.