Constraints are rules applied to form fields to define how data can be entered into them.

This is an optional feature utilised to suit certain form purposes but likely isn't required for every field, only a particular few.

Read on to see how constraints could apply to your forms.

Admin > InfoCapture > Form title > Edit form fields

To add a constraint to a field, edit a field from the admin side of the form.

Click on the 'Constraints' tab to reveal the options:

Some of the below options can be coupled to create data entry ranges or used independently to create limits.

- Reg.exp: Stands for 'regular expression' which are character sequences that specify a pattern. When used as a constraint data entry must adhere to the rules the expression represents. (Written to suit a particular purpose)

- Value >=: Numerical data entry in the form field will need to be greater than or equal to this number (if used alone) or the number is the maximum entry allowed (if used in tandem)

- Value <=: Numerical data entry in the form field will need to be less than or equal to this number (if used alone) or the number is the minimum entry allowed (if used in tandem)

- Size >=: Length of data entry must be greater than or equal to this number (when used alone or in tandem)

- Size <=: Length of data entry must be less than or equal to this number (when used alone or in tandem)

Enter your constraint values into the correct field(s) and click 'Save' to apply this to the form version, checking this in to apply to either new tickets or all past ones.

The next submission (or edit of a past ticket if applied to these) will see fields with constraints preventing data entry that does not fit the rules applied.

Which constraint do I need?

The two size constraints deal with the length of entries into a field that is acceptable, whether between a range or above/below, including the given number.

The two value constraints determine if entries must be higher or lower than the given number rule or if they must be between a certain range of numbers.

Regular expressions are unique as the rules they create are determined by the characters used to define the expression.

The examples below will demonstrate this functionality in further detail.

Examples

Size constraint: Data entry has a maximum character limit

Policy numbers at a company are always 8 characters long or less, so the form field needs to allow this but not entries over 8.

The size less than or equal to constraint can be used to set a maximum length of 8 but anything shorter than this is also allowed.

Submissions cannot be made until the rule is followed and users will be instructed on screen when data entry is not accepted.

Size constraint: Data entry has a minimum character limit 

A hotel's naming convention for their rooms has a minimum of two characters. 

To ensure at least two characters are entered into this form field, the size greater than or equal to constraint can be set on it as below.

Anything less than the minimum will be flagged to the user and submission prevented until it is rectified.

Size constraint: Data entry has to be a number of characters within a range
 

- String fields

A 'Reference code' field in a form will only ever have 4-6 characters.

To ensure this rule is applied to the field using constraints, a range of acceptable characters is applied using both size constraints to create an upper and lower limit.

When a user enters a number of characters outside the range, a tooltip will appear to inform them of the rule, as well as an on-screen error.

Submissions cannot be made until the rule is followed and an entry between 4 and 6 characters is given.

- Free text fields 

A 'Description' field in a form about bug reports is a free text field that allows an open answer, however, the administrators would like to limit this to 200 characters to ensure helpful but concise answers are facilitated.

The size constraints can be set up to create an acceptable range for this as below.

The tooltip instruction and on-screen error will appear if a user makes an entry outside of the range so that the user can rectify their answer to allow submission.

Value Constraint: Data entry has a maximum value
 

A 'Cost' field in a Purchasing form should never exceed £2000.

To prevent users from making submissions in the form with an amount over this, the value less than or equal to constraint can be put in place.

This defines that only numbers less than or equal to 2000 will submit successfully.

Submissions cannot be made with a value higher than the constraint allows and an on-screen error will detail this.

Value Constraint: Data entry has a minimum value

Using this logic it can also be ensured that instead submissions of over or including 2000 are made by using the greater than or equal to value option...

Submissions cannot be made with a value lower than the constraint allows and an on-screen error will detail this.

Value Constraint: Data entry has a numerical range

It is also possible to implement a numerical range of acceptable answers by using both value constraint options e.g. between 5 and 50.

The tooltip instruction with the rule will appear for incorrect entries, as well as an on-screen error.

In this example, the administrator has included the minimum amount required in the field label to curtail incorrect data entry from the users.

Reg exp: Limit data entry of a field to only x characters

In a form the string field 'Employee number' should only ever contain 10 characters.

To ensure this rule is applied to the field using a constraint, the regular expression below can be used to achieve this: (., ‘^[0-9]{10}$’)

Any entry that is not 10 characters exactly cannot be submitted:

Notice that the error message for Regular Expressions is more generic than those of the size and value constraints.

This is because a regular expression is setting a rule for a broader range of parameters that Claromentis cannot create a unique error for.

If this message is not detailed enough for your use case, add a notice field to accompany the constraint to instruct users what the restriction is.

Reg exp: Restrict field entry to x decimal places

A 'Width' field in a form about measurements for a blade saw needs to give very precise numbers.

However, administrators need this to consistently have 4 decimal places specified to ensure standardised data to give the manufacturer.

The below regular expression can be used to facilitate this: ^\d+\.\d{4}$

Any entry under or over 4 decimals will not be allowed to be submitted.

Reg exp: Ensure data entry does not include any whitespaces

A form deals with gathering information for new user accounts.

It's of paramount importance that the username field does not contain any whitespace.

The below regular expression can be used to make this rule: ^\S$

Any whitespace included when the ticket is attempted to be submitted will be flagged with an error and the user cannot continue until rectified.

Constraints are a great way to ensure data entry in fields is what an administrator needs from the end user.

More complex functions that cannot be achieved with constraints alone or use them as the basis for another process would likely need further investigation and custom work to support this in your form.

In these cases, please submit a change request ticket outlining your requirements and the team can assist you.