Main Content

Create Requirements Table Blocks Programmatically

You can create and manage Requirements Table blocks programmatically. In this example, you programmatically create a Requirements Table block in a new model, define block data, add requirements, and access requirement properties. For information on how to create and manage Requirements Table blocks with the graphical interface, see Use a Requirements Table Block to Create Formal Requirements.

Create a Requirements Table Block

Each Requirements Table block you add has an associated RequirementsTable object. Create a Requirements Table block in a new model named myNewModel by using the slreq.modeling.create function, and assign the block to a RequirementsTable object named table.

table = slreq.modeling.create("myNewModel");

If you have an existing model that you want to add a Requirements Table block to, use the add_block (Simulink) function and retrieve the RequirementsTable object by using slreq.modeling.find with the name of the block.

add_block("reqmanage/Requirements Table",...
strcat(gcs,"/Requirements Table"));
table = slreq.modeling.find(gcs);

Specify Requirements Table Block Name and Column Headers

After you add a Requirements Table block to a model, use dot notation to modify the Name and RequirementHeader properties. When you create a new Requirements Table block, the block uses the default name. Rename the block by modifying the Name property to My Requirements:

table.Name = "My Requirements";

You can add Precondition, Postcondition, and Action columns to the block by adjusting the RequirementHeader property. In this example, specify that the block contains two precondition columns and one postcondition column:

table.RequirementHeaders.Preconditions = ["input1","input2"];
table.RequirementHeaders.Postconditions = "output";

You can hide column types that you do not use in the Requirements tab and the Assumptions tab with the hideRequirementColumn and hideAssumptionColumn functions. This example does not use actions or durations. Hide the Action and Duration columns with the hideRequirementColumn function:



To delete columns, use the Requirements Table block graphical interface.

Define Data

In addition to adding data to the preconditions and postcondition, you must resolve the data by defining it. Currently, you have not defined input1, input2, and output. To define the data programmatically, use the addSymbol function on the RequirementsTable object. addSymbol allows you to adjust some of the properties of the data, including the data name, the scope, data type, and size. If you want to set additional properties, use the Symbols pane and Property Inspector in the graphical interface. For more information, see Define Data in Requirements Table Blocks.

Define data named input1, input2, and output and specify them as input data. Because output is the only data used in the postconditions, you must enable the isDesignOutput property for it. See isDesignOutput and Treat as design model output for analysis. Specify output as a design model output.


The Requirements Table block appears with one requirement, three columns, and the data in the column headers.

This image shows the Requirements Table block after entering the commands described up until this point. The table has one requirement, three columns, and the data are in each of the headers.

To modify the data, retrieve the Symbol object array with the findSymbol function and use dot notation. See Retrieve Data and Change It.

Add and Modify Requirements

To add requirements to the block, use the addRequirementRow function. To add assumptions, use the addAssumptionRow function. Each function adds one row. To add multiple rows, you can either repeat the entry or use a for loop and adjust the properties after creating them.

Add a requirement to the block and specify the summary, preconditions, and postconditions.

addRequirementRow(table,Summary="Requirement 2",...
Preconditions={'> 0',''});

The first requirement is empty. Use dot notation to specify the properties of an existing requirement. Retrieve the requirements as RequirementRow objects from the table and modify the first requirement.

rrow = getRequirementRows(table);
rrow(1).Summary = "Requirement 1";
rrow(1).Preconditions = {'0',''};
rrow(1).Postconditions = {'> 2'};

You can also add children to requirements or assumptions by using the addChild function. Add two children to the second requirement that specify the preconditions and postconditions.

addChild(rrow(2),Preconditions={'','> 0'},...
Postconditions={'> 5'});
addChild(rrow(2),Preconditions={'','<= 0'},...
Postconditions={'<= -1'});

To complete the requirement set, add a default row by using the addRequirementRow function and specifying the rowType as "default".

Postconditions={'< 1'});

After you enter the above commands, the Requirements tab lists the new requirements:

This image shows the Requirements Table block after executing the programmatic commands shown above. It includes the two top-level requirements, two children requirements of the second requirement, and a default requirement.

If you close out of the block, you can reopen it with the open_system function:

open_system("myNewModel/My Requirements");

Manage Requirements as slreq.Requirement Objects

Adding a Requirements Table block to a model creates a slreq.ReqSet object for each block, and creating requirements creates corresponding slreq.Requirement objects. To retrieve the objects from the table discussed in this example, load the requirement set into Requirements Toolbox™ and retrieve the slreq.ReqSet object with the slreq.load function:

[~,reqSet] = slreq.load("myNewModel.slx");
You can also use on the model, which loads the requirement set and opens the requirement set in the Requirements Editor.

After retrieving the slreq.ReqSet object, you can retrieve the properties like other requirement sets. Retrieve the slreq.Requirement objects with find.

requirements = find(reqSet,"Type","Requirement");

If you want to retrieve only the requirements at the highest hierarchy level, use the children function on the slreq.ReqSet object. You can then access the child requirements of each requirement by using the children function on each slreq.Requirement object.

If the Requirements Table block is open, you can retrieve slreq.Requirement objects by using the slreq.getCurrentObject function. To retrieve the slreq.Requirement object from the interface, select the requirement in the block or the Requirements Editor and enter slreq.getCurrentObject.

You can only adjust requirement hierarchy in the graphical interface. To add or remove requirements, use addRequirementRow and removeRow.

See Also


Related Topics