dependsOn

Create dependency between tasks

Syntax

dependsOn(taskObj,predecessors)

dependsOn(___,Name=Value)

Description

dependsOn(taskObj,predecessors) creates a dependency between taskObj and predecessors. taskObj runs only after the tasks specified by predecessors run and return a task status.

dependsOn(___,Name=Value) specifies how the build system handles predecessors using one or more Name=Value arguments.

Note

You can specify the relationship between two tasks as either a dependsOn relationship or a runsAfter relationship, but not both.

By default, if you define multiple relationships between the same tasks, the build system only uses the most recent relationship and ignores previous relationships. For example:

dependsOn(taskA, taskB)
dependsOn(taskB, taskA) % build system only uses this relationship

However, you can use the Override argument to explicitly replace an existing relationship with a new relationship.

Examples

Create Dependency Between Two Tasks

Use the dependsOn function to create a dependency between two tasks in a process model.

Open the Process Advisor example project.

processAdvisorExampleStart

Open the processmodel.m file. The file is at the root of the project.

Replace the contents of the processmodel.m file with the following code:

function processmodel(pm)
    arguments
        pm padv.ProcessModel
    end

    TaskA = padv.Task("TaskA");
    TaskB = padv.Task("TaskB");

    dependsOn(TaskB,TaskA);

    addTask(pm,TaskA);
    addTask(pm,TaskB);
    
end

This code uses padv.Task to create two task objects: TaskA and TaskB.

The object function dependsOn specifies that TaskB depends on TaskA.

The function addTask adds the task objects to the padv.ProcessModel object.

Open the Process Advisor app. In the MATLAB^® Command Window, enter:

processAdvisorWindow

In the Tasks column, point to the run button for TaskB. The Process Advisor app automatically highlights both tasks since TaskA is a predecessor task. If you click the run button for TaskB, TaskA will run before TaskB.

Input Arguments

taskObj — Task object that represents task

padv.Task object

Task object that represents a task, specified as a padv.Task object.

Example: myTaskObj = padv.Task("myTask");

predecessors — Tasks or subprocesses that need to run before this task runs

string | character vector | padv.Task object | array of padv.Task objects

Tasks or subprocesses that need to run before this task runs, specified as either the:

• Name of a task, specified as a string or character vector

• padv.Task object

• Array of task names

• Array of padv.Task objects

Example: dependsOn(TaskB,"TaskA")

Example: dependsOn(TaskB,TaskA)

Example: dependsOn(TaskC,[TaskA,TaskB])

Example: dependsOn(TaskC,["TaskA","TaskB"])

Data Types: char | string

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: dependsOn(TaskB,TaskA,WhenStatus=["Pass","Fail"])

IterationArtifactMatching — Option to control which predecessor task iterations run

true or 1 (default) | false or 0

Option to control which predecessor task iterations run, specified as a numeric or logical 1 (true) or 0 (false):

• true — The build system runs only iterations that the predecessor and source have in common.

• false — The build system runs all predecessor task iterations. This behavior is useful when you have a task that creates new project artifacts and a task that runs on each artifact in the project. The second task depends on all project artifacts generated by the first task.

For example, suppose you have two tasks: TaskA and TaskB:

• TaskA runs on ModelA and ModelB.

• TaskB runs only on ModelB and depends on TaskA.

If you run TaskB and:

• IterationArtifactMatching is true, TaskA runs only on ModelB.

  

• IterationArtifactMatching is false, TaskA runs on both ModelA and ModelB.

  

Example: dependsOn(TaskB,TaskA,IterationArtifactMatching=false)

Data Types: logical

Override — Replace existing task relationship

false or 0 (default) | true or 1

Replace existing task relationship, specified as a numeric or logical 0 (false) or 1 (true).

By default, if you define multiple relationships between the same tasks, the build system only uses the most recent relationship and ignores previous relationships. Setting the Override argument as 1 (true) makes sure that the current task relationship replaces any existing relationship between the tasks.

Data Types: logical

WhenStatus — Option to control when this task or subprocess runs

"Pass" (default) | "Fail" | "Error" | ["Pass","Fail"] | ["Pass","Fail","Error"]

Option to control when the source task or subprocess runs, specified as either "Pass", "Fail", "Error", or a combination of those options.

For example, you can specify ["Pass","Fail"] to instruct the build system to only run the source if the predecessors pass or fail. By default, the source only runs if the predecessors pass.

Example: dependsOn(TaskB,TaskA,WhenStatus=["Pass","Fail"])

Data Types: string

Tips

In your process model, you can specify the relationship between tasks as either a dependsOn or runsAfter relationship. If you want to specify a preferred task execution order for tasks that do not depend on each other, you can specify your preferred task execution order by using the runsAfter method instead. For more information, see Define Task Relationships.