DHTMLX Planning Engine Documentation

Slot#

One position to staff on one task: the task, the resources eligible for it, and the assignment that fills it, if any. Pass a list of slots to Project.SuggestAssignments. Build them yourself with the constructor, or get them from skills and requirements with SkillLayer.Slots.

A slot carries no skills, only resource ids.

Declaration#

namespace Plen;

public sealed class Slot : IDeepCloneable<Slot>, IEquatable<Slot>

Id, Task and Allowed are required. Set them in an object initializer or use the constructor.

Constructors#

Slot(Id, Id, List<Id>)#

public Slot(Id id, Id task, List<Id> allowed)

Creates an empty slot with Value = 1.0 and Assignment = null. The list is stored as passed, not copied.

Name Type Description
id Id Slot id.
task Id Task to staff.
allowed List<Id> Eligible resources, in preference order.

Properties#

Property Type Default Description
Id Id required Slot id. An assignment created to fill the slot gets this id, so after you commit it, set Assignment to the slot id to keep the binding on the next run.
Task Id required A scheduled leaf task.
Allowed List<Id> required Resources eligible for the slot. The order is the tie-break preference when two candidates score the same.
Value double 1.0 Units of the assignment created when the slot is filled (1.0 = 100 %). Must be finite and greater than 0.
Assignment Id? null The active assignment on Task that fills the slot. null means the slot is empty.

The slot's category (empty, or filled by a resource inside or outside Allowed) follows from Assignment and Allowed. It decides whether the slot is filled, repaired or rebalanced; see AssignTarget.

Project.SuggestAssignments checks every slot before it runs. The checks and their InputException paths are listed under Errors.

Methods#

DeepClone#

public Slot DeepClone()

Returns a deep copy. Allowed is copied, so nothing is shared with the original.

Equals#

public bool Equals(Slot? other)
public override bool Equals(object? obj)

Two slots are equal when Id, Task, Value and Assignment are equal and Allowed holds the same ids in the same order. Value is compared with ==.

GetHashCode() follows the same rule.

ToString#

public override string ToString()

Returns a readable rendering of every property, for logging.

Example#

Staff task 1 with one reviewer at half time, chosen from ann and bob, then commit the pick.

using Plen;

var monday = Moment.FromYmdHm(2026, 8, 10, 8, 0)
    ?? throw new InvalidOperationException("invalid date");

var data = new ProjectData
{
    Tasks = [new TaskData(1) { StartDate = monday, Duration = 3.0 }],
    Resources = [new ResourceData { Id = "ann" }, new ResourceData { Id = "bob" }],
};

var project = new Project();
project.Solve(data, new SolveOptions());

var slots = new List<Slot>
{
    new("review", 1, ["ann", "bob"]) { Value = 0.5 },
};

var result = project.SuggestAssignments(slots, new SuggestOptions());
foreach (var step in result.Steps)
    Console.WriteLine($"{step.Slot}: {step.ToResource}");

project.Apply(result.Changes);
// On the next run, bind the slot to the assignment it created:
// new("review", 1, ["ann", "bob"]) { Value = 0.5, Assignment = "review" }