Dynamic

Dynamic problems are a special type of custom problem that allows a problem creator to provide a unique problem description to each user. The problem creator can specify their dynamic problem generation script in On Start Command setting for Custom problems. The On Start Command will be triggered when the user copies the assignment or when they view the assignment.

Settings

On Start Command

The on start command should be a UNIX shell command. It is run once when a user first views the assignment and every time the number of submissions hits the soft limit count.

Soft Limit

To control after which submission count the on start command should be run again, set the soft limit to a value greater than 0. Otherwise, this setting defaults to 0.

Figure 1. Custom problem advanced settings view

On Start Metadata

On start metadata can provide information to the On Start Command to determine what problem to generate. The path of the metadata file will be passed in as the last argument to your On Start Command. The file will be of JSON format as shown below:

{
    first_name: "John",
    last_name: "Doe",
    email: "[e-mail]",
    timestamp: "2017-11-26 23:21:02 -0800",
    previous: [
        {
            description: "<PREVIOUS PROBLEM DESCRIPTION>",
            created_at: "2017-11-25 23:21:02 -0800",
            updated_at: "2017-11-25 23:21:02 -0800",
            data: "<PREVIOUS DATA>"
        },
        ...
    ]
}

• first_name

  A string describing the first name of the submitter.

• last_name

  A string describing the last name of the submitter.

• email

  A string describing the email of the submitter.

• timestamp

  A timestamp string describing when the submission was made.

• previous

  A list of previously generated on start responses.

Expected Response

The below format should be output to stdout as a JSON string:

{
    description: "<YOUR PROBLEM DESCRIPTION>",
    description_format: "[markdown]",
    data: "<ASSOCIATED DATA FOR PROBLEM>",
    data_format: "[input, mc, image]"
}

• description

  Text describing the problem.

• description_format (optional)

  default: the description will be rendered in a <pre> element.

  markdown: the problem description will be rendered as markdown with MathJax support.

• data

  JSON encode-able object

• data_format (Optional)

  • image

    If set, expects the data attribute to be of the form:

    {
        base64_str: "",
        mime_content_type: ['jpeg', 'png', ...]
    }