graphflow supports the building, execution and graphical rendering of simple linear workflows.
There may be times when complex business logic is best represented in the form of a decision tree or a workflow made up of a series of yes/no questions and actions or decisions that should be taken.
The graphflow package allows this logic to be built and represented as a self-documenting series of Task nodes with conditional Paths between them, allowing a project stakeholder to easily validate what has been built.
- A sensible API to construct a graphflow from Tasks and Paths
- Shared ExecutionContext passed between Tasks in which any data can be stored
- Rendering of the graphflow structure
- Rendering of the path taken through a graphflow, given a particular context
$ go get github.com/futrli/graphflowpackage main
import (
"fmt"
"io/ioutil"
"log"
"github.com/futrli/graphflow/_examples/tasks"
"github.com/futrli/graphflow"
"github.com/futrli/graphflow/rendering"
)
// my graphflow:
func buildGraphflow() *graphflow.Graphflow {
gf := new(graphflow.Graphflow)
// create task instances and add to graphflow
start := gf.AddTask(new(graphflow.StartTask))
isTheSkyCloudy := gf.AddTask(new(tasks.IsTheSkyCloudy))
forecastFog := gf.AddTask(new(tasks.ForecastFog)) // leave this deliberately orphaned with no Paths in or out
forecastRain := gf.AddTask(new(tasks.ForecastRain))
forecastSun := gf.AddTask(new(tasks.ForecastSun))
end := gf.AddTask(new(graphflow.EndTask))
// add task paths to the graphflow
gf.AddPath(start, graphflow.ALWAYS, isTheSkyCloudy)
gf.AddPath(isTheSkyCloudy, graphflow.YES, forecastRain)
gf.AddPath(isTheSkyCloudy, graphflow.NO, forecastSun)
gf.AddPath(forecastRain, graphflow.ALWAYS, end)
gf.AddPath(forecastSun, graphflow.ALWAYS, end)
// create a task group
forecastingGroup := gf.NewTaskGroup("Forecasting")
// add forecasting tasks to this group
forecastingGroup.AddTasks(forecastFog, forecastRain, forecastSun)
return gf
}
func main() {
ctx := new(graphflow.ExecutionContext)
//ctx.Set("Sky", "Clear")
ctx.Set("Sky", "Cloudy")
ctx.Set("Forecast", "")
gf := buildGraphflow()
err := gf.Run(ctx)
if err != nil {
log.Fatalf("Error: %s\n", err)
}
fmt.Printf("Successfully forecasted: %v\n", ctx.Get("Forecast"))
buf, _ := rendering.RenderGraph(gf)
ioutil.WriteFile("./graph.png", buf.Bytes(), 0664)
buf, _ = rendering.RenderPathThroughGraph(ctx, gf, "Sky")
ioutil.WriteFile("./pathThroughGraph.png", buf.Bytes(), 0664)
}
