HTMLInputElement.md

HTMLInputElement

Namespace: SpawnDev.SpawnJS.JSObjects
Inheritance: SpawnJSObject -> EventTarget -> Node -> Element -> HTMLElement -> HTMLInputElement
MDN Reference: HTMLInputElement on MDN
Source: SpawnDev.SpawnJS/JSObjects/DOM/HTMLInputElement.cs

The HTMLInputElement interface provides properties and methods for manipulating the layout and presentation of input elements. It covers all input types (text, checkbox, radio, file, range, etc.) with type-specific properties.

Constructor

public HTMLInputElement(SpawnJSObjectReference _ref)

Properties

Property	Type	Description
Accept	string	File types accepted (for type="file").
Alt	string	Alt text (for type="image").
Autocomplete	string	Get/set autocomplete hint ("on"/"off"/specific values).
Checked	bool	Get/set the checked state (checkbox/radio).
DefaultChecked	bool	The default checked state.
DefaultValue	string	The default value.
Disabled	bool	Get/set the disabled state.
Files	FileList?	The selected files (for type="file").
Form	HTMLFormElement?	The containing form.
FormAction	string	Override the form's action URL.
FormEnctype	string	Override the form's encoding type.
FormMethod	string	Override the form's HTTP method.
FormNoValidate	bool	Override the form's novalidate.
FormTarget	string	Override the form's target.
Height	int	Height (for type="image").
Indeterminate	bool	Get/set the indeterminate state (checkbox).
Max	string	The maximum value.
MaxLength	int	Maximum character length.
Min	string	The minimum value.
MinLength	int	Minimum character length.
Multiple	bool	Whether multiple values are allowed (file/email).
Name	string	Get/set the element name.
Pattern	string	Validation pattern (regex).
Placeholder	string	Placeholder text.
ReadOnly	bool	Get/set read-only state.
Required	bool	Get/set required state.
SelectionDirection	string	Direction of text selection.
SelectionEnd	int?	End index of text selection.
SelectionStart	int?	Start index of text selection.
Size	int	Display size (character width).
Src	string	Image source URL (for type="image").
Step	string	Step increment for numeric/date inputs.
Type	string	Get/set the input type ("text", "password", "checkbox", etc.).
Value	string	Get/set the current value.
ValueAsDate	DateTime?	Get/set the value as a DateTime.
ValueAsNumber	double	Get/set the value as a number.
Width	int	Width (for type="image").

Methods

Method	Return Type	Description
Select()	void	Select all text in the input.
SetSelectionRange(int start, int end)	void	Set the text selection range.
SetSelectionRange(int start, int end, string direction)	void	Set selection range with direction ("forward"/"backward"/"none").
StepUp()	void	Increment the value by one step.
StepUp(int n)	void	Increment the value by n steps.
StepDown()	void	Decrement the value by one step.
StepDown(int n)	void	Decrement the value by n steps.
CheckValidity()	bool	Check if the input satisfies its constraints.
ReportValidity()	bool	Check validity and show validation UI.
SetCustomValidity(string message)	void	Set a custom validation message.

Events

Event	Type	Description
OnInput	ActionEvent<Event>	Fired when the value changes.
OnChange	ActionEvent<Event>	Fired when a change is committed (blur or Enter).
OnInvalid	ActionEvent<Event>	Fired when the element fails validation.
OnSelect	ActionEvent<Event>	Fired when text is selected.

Example

using var input = doc.QuerySelector<HTMLInputElement>("#username");

// Read value
string username = input!.Value;

// Validation
input.Required = true;
input.MinLength = 3;
input.Pattern = "^[a-zA-Z0-9]+$";

if (!input.CheckValidity())
{
    input.SetCustomValidity("Username must be alphanumeric, 3+ characters");
}

// Events
void OnInput(Event e)
{
    Console.WriteLine($"Current value: {input.Value}");
}
input.OnInput += OnInput;
// ... later
input.OnInput -= OnInput;

Example - File Input

using var fileInput = doc.QuerySelector<HTMLInputElement>("input[type=file]");
fileInput!.Accept = "image/*";
fileInput.Multiple = true;

void OnChange(Event e)
{
    using var files = fileInput.Files;
    if (files != null)
    {
        for (int i = 0; i < files.Length; i++)
        {
            using var file = files[i];
            Console.WriteLine($"File: {file.Name}, Size: {file.Size}");
        }
    }
}
fileInput.OnChange += OnChange;