constraint.StringStartsWith

Constraint: StringStartsWith

Description

Check that a string starts with a given prefix

Note: By default, this constraint is non-strict - if the value being checked is not a string, this constraint does not fail (unless the Strict field is set)

V8n Tag Abbreviation

starts

Fields

Field	Type	Description
Value	string	the value to check that the string starts with
Values	[]string	multiple additional values that the string may start with
CaseInsensitive	bool	whether the check is case-insensitive (by default, the check is case-sensitive)
Not	bool	whether the check is NOT-ed (i.e. checks that the string does not start with)
Message	string	the violation message to be used if the constraint fails. If empty, the default message is used
Stop	bool	when set to true, Stop prevents further validation checks on the property if this constraint fails
Strict	bool	when set to true, fails if the value being checked is not a correct type

Examples

Programmatic example...

package main

import (
    "fmt"

    "github.com/marrow16/valix"
)

func main() {
    validator := &valix.Validator{
        Properties: valix.Properties{
            "foo": {
                Type: valix.JsonString,
                Constraints: valix.Constraints{
                    &valix.StringStartsWith{
                        Value:           "foo",
                        CaseInsensitive: true,
                    },
                },
            },
        },
    }

    ok, violations, _ := validator.ValidateString(`{"foo": "there isn't a foo at the start of this"}`)
    fmt.Printf("Passed? %v\n", ok)
    for i, v := range violations {
        fmt.Printf("Violation[%d] Message: %s, Property: %s, Path: %s\n", i+1, v.Message, v.Property, v.Path)
    }

    ok, violations, _ = validator.ValidateString(`{"foo": "Foo is at the start"}`)
    fmt.Printf("Passed? %v\n", ok)
    for i, v := range violations {
        fmt.Printf("Violation[%d] Message: %s, Property: %s, Path: %s\n", i+1, v.Message, v.Property, v.Path)
    }
}

try on go-playground

Struct v8n tag example...

package main

import (
    "fmt"

    "github.com/marrow16/valix"
)

type MyStruct struct {
    Foo string `json:"foo" v8n:"&starts{Value:'foo', insensitive:true}"`
}

var validator = valix.MustCompileValidatorFor(MyStruct{}, nil)

func main() {
    my := &MyStruct{}

    ok, violations, _ := validator.ValidateStringInto(`{"foo": "there isn't a foo at the start of this"}`, my)
    fmt.Printf("Passed? %v\n", ok)
    for i, v := range violations {
        fmt.Printf("Violation[%d] Message: %s, Property: %s, Path: %s\n", i+1, v.Message, v.Property, v.Path)
    }

    ok, violations, _ = validator.ValidateStringInto(`{"foo": "Foo is at the start"}`, my)
    fmt.Printf("Passed? %v\n", ok)
    for i, v := range violations {
        fmt.Printf("Violation[%d] Message: %s, Property: %s, Path: %s\n", i+1, v.Message, v.Property, v.Path)
    }
}

try on go-playground