System Configuration field Validation

Question

I want to Validate Max-limit in system configuration field. i have used some of classes for other validation but did not found any class for max or min text limit for system configuration filed.

Answer 1

You can use this code for better output with validation :

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Config:etc/system_file.xsd">
    <system>
        <tab id="tabID" translate="label" sortOrder="10">
            <label>Tab Name</label>
        </tab>
        <section id="sectionID" translate="label" type="text" sortOrder="300" showInDefault="1" showInWebsite="1" showInStore="1">
            <label>General Configuration</label>
            <tab>Section</tab>
            <group id="groupID" translate="label" type="text" sortOrder="1" showInDefault="1" showInWebsite="1" showInStore="1">
                <field id="fieldID" translate="label comment" sortOrder="0" type="text" showInDefault="1" showInWebsite="0" showInStore="0">
                    <label>Maximum Number of Items to Display</label>
                    <validate>required-entry validate-digits validate-not-negative-number validate-length minimum-length-7 maximum-length-20 </validate>
                </field>
            </group>
        </section>
    </system>

• required-entry : For required field
• validate-digits : For use numbers only in this field.
• validate-not-negative-number : For enter a number 0 or greater.
• validate-length : For a specific valid length.
• minimum-length-7 maximum-length-20 : Min length is 7 and Max length is 20.

Answer 2

Thank you for asking about this validation. Use this validation for your query:

<validate>validate-length maximum-length-50</validate>

For Example:

<group id="customer_service" translate="label" type="text" sortOrder="35" showInDefault="1" showInWebsite="1" showInStore="1">
            <label>Customer Service</label>
            <field id="number" translate="label" type="text" sortOrder="9" showInDefault="1" showInWebsite="1" showInStore="1">
                <label>Enter Contact Number</label>
                <comment>Please enter an internationalized version of the phone number. For example +91 XXX XXXXXXX</comment>
                <validate>validate-length maximum-length-22</validate>
            </field>
</group>