expressionConvert.go

package main

import (
	"fmt"

	"github.com/fabric8-services/fabric8-wit/criteria"
	"github.com/fabric8-services/fabric8-wit/workitem"
)

type Node struct {
	Name     string
	Value    *string
	Children []*Node
}

func main() {
	planner := "planner"
	osio := "openshiftio"
	rhel := "rhel"
	a := Node{
		Name:  "OR",
		Value: nil,
		Children: []*Node{
			&Node{
				Name:  "AND",
				Value: nil,
				Children: []*Node{
					&Node{
						Name:     "space",
						Value:    &osio,
						Children: nil,
					},
					&Node{
						Name:     "area",
						Value:    &planner,
						Children: nil,
					},
				},
			},
			&Node{
				Name:     "space",
				Value:    &rhel,
				Children: nil,
			},
		},
	}

	b := Node{
		Name:  "AND",
		Value: nil,
		Children: []*Node{
			&Node{
				Name:     "space",
				Value:    &osio,
				Children: nil,
			}, &Node{
				Name:     "area",
				Value:    &planner,
				Children: nil,
			},
		},
	}
	e1 := generateExpression2(&a)
	where1, parameters1, compileError1 := workitem.Compile(e1)
	fmt.Println(where1, parameters1, compileError1)

	e2 := generateExpression2(&b)
	where2, parameters2, compileError2 := workitem.Compile(e2)
	fmt.Println(where2, parameters2, compileError2)
}

func isOperator(str string) bool {
	return str == "AND" || str == "OR"
}

func generateExpression2(n *Node) criteria.Expression {
	var myexpr []criteria.Expression
	currentOperator := n.Name
	if !isOperator(currentOperator) {
		q := criteria.Equals(criteria.Field(n.Name), criteria.Literal([]string{*n.Value}))
		myexpr = append(myexpr, q)
	}
	for _, child := range n.Children {
		if isOperator(child.Name) {
			q := generateExpression2(child)
			myexpr = append(myexpr, q)
		} else {
			q := criteria.Equals(criteria.Field(child.Name), criteria.Literal([]string{*child.Value}))
			myexpr = append(myexpr, q)
		}
	}
	var e criteria.Expression
	switch currentOperator {
	case "AND":
		for _, o := range myexpr {
			if e == nil {
				e = o
			} else {
				e = criteria.And(e, o)
			}
		}
	case "OR":
		for _, o := range myexpr {
			if e == nil {
				e = o
			} else {
				e = criteria.Or(e, o)
			}
		}
	}
	return e
}