Constraint Input

Pattern Description

When system expects input data from user in specific format, type or syntax but user have not much clear idea about it. Then it is suggested to use constraint input with pre-defined data. The goal of this pattern is to help user choose from the pre-defined options to provide inputs.

Problem Statement

When user needs to enter data to the system but have no clear idea what to put and in what format and expected correct format. And system has assumptions of the correct form of data and without which unable to function in proper way.

Use When

System needs a sanitized and pre-defined form of data and as per the requirement of the system to function properly. And user has not clear idea about how to provide correct data as input.

Solution

Provide options with system acceptable data to the user so that user could not able to enter beyond the pre-defined input data.

Rationale

Some time system needs can not able to function properly without the pre-determined data, which is very common. It is obvious to the user that system needs to provide these pre-determined data to the user to choose form, to help user easily understand the options.

Examples