DHTMLX Planning Engine Documentation

MutationKind#

The kind of task an update entry describes: a regular task, a summary or a milestone. It's the type of the Mutation::kind field, and it matches the task's TaskType in the input data.

Declaration#

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum MutationKind {
    Task,
    Summary,
    Milestone,
}

With the serde feature, MutationKind implements Serialize and Deserialize. Variants are written in kebab-case: "task", "summary", "milestone".

Variants#

Variant Serialized Description
Task "task" The entry belongs to a regular task (TaskType::Task).
Summary "summary" The entry belongs to a summary task (TaskType::Summary).
Milestone "milestone" The entry belongs to a milestone (TaskType::Milestone).

For how an entry is fed back into the project, see Mutation.

Example#

Schedule a summary with one task and a closing milestone, then group the update entries by kind:

use plen_core::{
    schedule, DateTime, MutationKind, ProjectData, SolveOptions, TaskData, TaskType,
};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let start = DateTime::from_ymd_hm(2026, 4, 6, 8, 0).ok_or("invalid date")?;

    let data = ProjectData {
        tasks: vec![
            TaskData { task_type: TaskType::Summary, ..TaskData::new("phase") },
            TaskData {
                parent: Some("phase".into()),
                start_date: Some(start),
                duration: Some(3.0),
                ..TaskData::new("build")
            },
            TaskData {
                parent: Some("phase".into()),
                task_type: TaskType::Milestone,
                start_date: Some(start),
                duration: Some(0.0),
                ..TaskData::new("release")
            },
        ],
        ..Default::default()
    };

    let options = SolveOptions { include_unchanged: true, ..Default::default() };
    let result = schedule(data, &options)?;

    for update in &result.updates {
        let label = match update.kind {
            MutationKind::Task => "task",
            MutationKind::Summary => "summary",
            MutationKind::Milestone => "milestone",
        };
        println!("{:?} ({label}): {:?} -> {:?}", update.id, update.start_date, update.end_date);
    }
    Ok(())
}