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Textarea tag helper

As explained in ASP.NET Core in Action, 3e

The Textarea Tag Helper is an ASP.NET Core Tag Helper that generates textarea elements and populates them from a bound property.

The Textarea Tag Helper creates a <textarea> from a model property with asp-for. It places the property value inside the element and adds the name, id, and validation attributes needed for server binding. section 18.2.3

Bind a multiline property

Use <textarea asp-for="BigtextValue"></textarea>. If the property contains text, ASP.NET Core renders that value inside the textarea and can add data-val-* attributes for requirements such as maximum length and required input.

How ASP.NET Core in Action, 3e covers it

How deep it goes
Explains syntax and generated HTML, including values and validation attributes, without descending into Tag Helper internals.
Examples
Uses a BigtextValue property containing multiline text and a generated maxlength-style validation example.
What it assumes
Assumes familiarity with forms, labels, inputs, and model properties before adding textarea fields.
What you can do after
Apply it via ASP.NET Core Razor markup to generate bound, validated textarea controls.
How it connects
Connects Tag Helpers with asp-for, model binding, DataAnnotations, and validation attributes.
Cover of ASP.NET Core in Action, 3e
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Related concepts

This explainer was generated by Manning's knowledge graph from the text of ASP.NET Core in Action, 3e. The section links point to the parts of the book it draws on.