Client-side validation
Client-side validation is checking user-supplied data in software running on the user's device before it is sent to a server or other remote system.
ASP.NET Core in Action, 3e
Client-side validation is validation performed in client software, typically a browser, before submitted data reaches the server.
- How it is used
- Provides immediate form feedback in Razor Pages before an invalid request reaches the server.
- How deep it goes
- Explains HTML5 checks, generated validation attributes, and required scripts; refers custom jQuery adapters to external documentation.
- Examples
- Uses an email input and its generated HTML to show validation before submission.
- What you can do after
- Apply it via Razor Pages Input Tag Helpers and jQuery Validation without replacing server-side checks.
Read how ASP.NET Core in Action, 3e explains client-side validation →
Pro ASP.NET Core 7, Tenth Edition
Client-side validation is the technique of checking user-entered data in the client environment before the form data is sent to the server.
- How it is used
- Checks form entries before submission to give users immediate feedback while complementing server-side model validation.
- How deep it goes
- Explains generated validation attributes and library roles, then gives package and script setup; custom client-side extension is deferred.
- Examples
- Uses a checkout form, a generated required-field input, LibMan commands, and a shared Razor view containing validation scripts.
- What you can do after
- Apply it via ASP.NET Core form tag helpers and the jQuery validation scripts to check form values before submission.
Read how Pro ASP.NET Core 7, Tenth Edition explains client-side validation →
Building Web APIs with ASP.NET Core
Client-side validation is the checking of user input in the client application before a request is sent to a server.
- How it is used
- Improves the API client experience by blocking invalid requests before they reach the server.
- How deep it goes
- Demonstrates automatic SwaggerUI checks and their limits, but defers implementation of general client-side validation controls.
- Examples
- Uses GET /BoardGames parameters, invalid integer input, Try It Out, and generated parameter constraints.
- What you can do after
- Apply it via SwaggerUI to catch invalid inputs early, while retaining server-side checks for data integrity.
Read how Building Web APIs with ASP.NET Core explains client-side validation →
Build AI-Enhanced Web Apps
Client validation is the checking of user-supplied data in a client application before it is sent to a server.
- How it is used
- Improves user experience by providing immediate feedback before data reaches a server.
- How deep it goes
- Defines browser-side checking and its bypass risk, but stops short of treating it as sufficient security.
- Examples
- Uses a React or Next.js textarea with maxLength={1000} for prompt-length feedback.
- What you can do after
- Apply it via React or Next.js form controls while retaining server-side validation for every request.
Read how Build AI-Enhanced Web Apps explains client-side validation →
Rust Servers, Services, and Apps
Client-side validation is validation of submitted data performed in the user's browser before a request is processed by a server.
- How it is used
- Uses browser-side HTML constraints to provide immediate registration feedback before sending a POST request.
- How deep it goes
- Demonstrates required fields and length limits, while deferring password confirmation to server-side validation.
- Examples
- Uses tutor registration fields with required, minlength, and maxlength attributes as concrete validation examples.
- What you can do after
- Apply it via HTML form attributes to enforce mandatory fields and basic field lengths in a browser.
Read how Rust Servers, Services, and Apps explains client-side validation →
Related concepts
- server validationcontrasts with · Server validation is the checking of client-submitted or request data on a server before processing, accepting, or storing it.
- validationcontrasts with · The process of checking data, behavior, systems, models, or results against defined criteria to assess their correctness, suitability, or acceptability.
- authenticationcontrasts with · Authentication is the process of establishing or verifying the identity of a user, service, device, or other communicating entity.
- JavaScriptused by · JavaScript is a high-level, dynamically typed, multi-paradigm programming language standardized as ECMAScript and used for web and general-purpose programming.
- Razor Pagesconfigured by · Razor Pages is an ASP.NET Core page-focused programming model in which independently addressable pages combine Razor markup with request-handling logic.
- validation attributecontrasts with · A validation attribute is metadata attached to a class or member that applies a rule for determining whether data satisfies specified requirements.
These guides are generated from the text of Manning books by Manning's knowledge graph and link to the sections they draw on. The full books are available on liveBook and at manning.com.