dart:convert

HtmlEscape class

Converter which escapes characters with special meaning in HTML.

The converter finds characters that are significant in the HTML source and replaces them with corresponding HTML entities.

The characters that need escaping in HTML are:

• & (ampersand) always needs to be escaped.
• < (less than) and > (greater than) when inside an element.
• " (quote) when inside a double-quoted attribute value.
• ' (apostrophe) when inside a single-quoted attribute value. Apostrophe is escaped as ' instead of ' since not all browsers understand '.
• / (slash) is recommended to be escaped because it may be used to terminate an element in some HTML dialects.

Escaping > (greater than) isn't necessary, but the result is often found to be easier to read if greater-than is also escaped whenever less-than is.

Example:

const HtmlEscape htmlEscape = HtmlEscape();
String unescaped = 'Text & subject';
String escaped = htmlEscape.convert(unescaped);
print(escaped); // Text & subject

unescaped = '10 > 1 and 1 < 10';
escaped = htmlEscape.convert(unescaped);
print(escaped); // 10 &gt; 1 and 1 &lt; 10

unescaped = "Single-quoted: 'text'";
escaped = htmlEscape.convert(unescaped);
print(escaped); // Single-quoted: &#39;text&#39;

unescaped = 'Double-quoted: "text"';
escaped = htmlEscape.convert(unescaped);
print(escaped); // Double-quoted: &quot;text&quot;

unescaped = 'Path: /system/';
escaped = htmlEscape.convert(unescaped);
print(escaped); // Path: &#47;system&#47;

Inheritance

• Object
• StreamTransformerBase<String, String>
• Converter<String, String>
• HtmlEscape

Constructors

HtmlEscape([HtmlEscapeMode mode = HtmlEscapeMode.unknown])

const

Create converter that escapes HTML characters.

Properties

hashCode → int

read-only, inherited

The hash code for this object.

mode → HtmlEscapeMode

final

The HtmlEscapeMode used by the converter.

runtimeType → Type

read-only, inherited

A representation of the runtime type of the object.

Methods

bind(Stream<String> stream) → Stream<String>

inherited

Transforms the provided stream.

cast<RS, RT>() → Converter<RS, RT>

inherited

Provides a Converter<RS, RT> view of this stream transformer.

convert(String text) → String

override

Converts input and returns the result of the conversion.

fuse<TT>(Converter<String, TT> other) → Converter<String, TT>

inherited

Fuses this with other.

noSuchMethod(Invocation invocation) → dynamic

inherited

Invoked when a non-existent method or property is accessed.

startChunkedConversion(Sink<String> sink) → StringConversionSink

override

Starts a chunked conversion.

toString() → String

inherited

A string representation of this object.

Operators

operator ==(Object other) → bool

inherited

The equality operator.