Validation Types

How many different ways or types of validation can we carry out.

• → Scenarios: When to Validation
• → Required Inputs
• → Min-Length Validation
• → Data Type Validation
• → Custom Expression Validation

Custom Expression Validation

Whether a field is required or not, a field can be checked against a number of custom expressions. If a field is not required, the custom expression validation is checked only if the input has value.

The input attribute data-val-checkAgainst is used to specify a number pre-defined type of expressions.

You can test for the following types of custom expressions:

Equal To | Another Input | An Array | Numeric Operators | String Operators | Date Operators | RegEx Expression

String Operators

Supply a string operator expression. The input field's value must match the expression. Expressions start with a prefix (exp: ), then a space and then the operator such as !=, ==, etc. Expressions are case sensitive except for the operators that specify otherwise.

Follow are the numeric operator data-val-checkAgainst options:

'exp: == S' - Checks if the value is equal to the string (S)
'exp: != S' - Checks if the value is NOT equal to the string (S)
'exp: ^= S' - Checks if the value starts with the string (S)
'exp: ^i= S' - Checks if the value starts with the string (S) - not case sensitive
'exp: $= S' - Checks if the value ends with the string (S)
'exp: $i= S' - Checks if the value ends with the string (S) - not case sensitive
'exp: *= S' - Checks if the value contains the string (S)
'exp: *i= S' - Checks if the value contains the string (S) - not case sensitive
Example:

<input type="text" name="string1"  data-val-required="1"  data-val-checkAgainst="exp: == Hello"  />
<input type="text" name="string2"  data-val-required="1"  data-val-checkAgainst="exp: != Hello"  />
<input type="text" name="string3"  data-val-required="1"  data-val-checkAgainst="exp: ^= He"  />
<input type="text" name="string4"  data-val-required="1"  data-val-checkAgainst="exp: ^i= He"  />
<input type="text" name="string5"  data-val-required="1"  data-val-checkAgainst="exp: $= lo"  />
<input type="text" name="string6"  data-val-required="1"  data-val-checkAgainst="exp: $i= lo"  />
<input type="text" name="string7"  data-val-required="1"  data-val-checkAgainst="exp: *= ll"  />
<input type="text" name="string8"  data-val-required="1"  data-val-checkAgainst="exp: *i= ll"  />

Numeric Operator Equal to 'Hello' Numeric Operator Not equal to 'Hello' Numeric Operator Starts with 'He' Numeric Operator Starts with 'He' - not case sensitive Numeric Operator Ends with 'lo' Numeric Operator Ends with 'lo' - not case sensitive Numeric Operator Contains with 'll' Numeric Operator Contains with 'll' - not case sensitive