HTML parser and non-strict validator
npm install @desertnet/html-parser
This HTML parser and validator is not a strict HTML parser in the vein of the XHTML strict validators of old. Instead, it aims to parse HTML as browsers do and only surface errors that are likely to confuse browsers or that are indicative of a confused HTML author.
``sh`
npm install --save @desertnet/html-parser
`javascript
const HTMLParser = require('@desertnet/html-parser')
const html =
I forgot to close my b tag.
I&npsb;misspelled the no-break-space entity.
.trim()const errors = HTMLParser.validate(html)
errors.forEach(error => {
console.log(
${error.message} (line: ${error.line}, column: ${error.column}))
})
`Outputs:
Could not find closing tag for "". (line: 2, column: 3)
Unexpected closing tag, "". Expected closing tag for "". (line: 3, column: 1)
Invalid HTML entity name for "&npsb;". (line: 6, column: 5)
API
$3
Static method on
constructor. It parses the HTML fragment in htmlString and returns an array of HTMLParseErrors. If there were no errors, an empty array is returned.$3
The
HTMLParser constructor. It takes no arguments.`javascript
const parser = new HTMLParser()
`#### .parse(htmlString)
Parses the HTML fragment in
and returns an HTMLNode object containing the parsed HTML.`javascript
const parseTree = parser.parse('Hello world!
')
`$3
Represents an error discovered durning parsing of an HTML fragment.
javascript
parseTree.errors.forEach(error => {
console.log(${error.message} (line: ${error.line}, column: ${error.column}))
})
`#### .message
Property that is a string containing an English description of the error.
#### .startIndex
Property that is a number indicating the index into the source string where the error begins.
#### .endIndex
Property that is a number indicating the index into the source string where the error ends.
#### .line
Property that is a number indicating the line number where the error begins. Line numbers being at
, not 0.#### .column
Property that is a number indicating the column of the line where the error begins. Columns also begin at
1, not 0.$3
The base class for all node types. Returned by
HTMLParser's .parse method.`javascript
console.log(indentedNodeList(parseTree))function indentedNodeList (node, indent = '') {
let str = ''
if (node.children) {
str += node.children.reduce((prev, child) => {
return prev + indentedNodeList(child,
${indent} )
}, '')
}
return ${indent}${node.type}\n${str}
}
#### .type
Property indicating the type of node. It will be one of the following strings:
-
: Root node of the tree.
- TAG: An HTML tag.
- ATTRIBUTE: An attribute of an HTML tag.
- TEXT: A text content node.
- ENTITY: An HTML entity (i.e. &)
- COMMENT: An HTML comment tag.
- CLOSETAG: A closing HTML tag.#### .children
Property that is either
null, or an array of HTMLNodes that are the node's children.#### .indexRange
Property that, if non-null, will be an array of two numbers. The first is the index of the source string where the node begins, and the second is the index of the source string where the node ends.
#### .errors
Property that is an array of
HTMLParseErrors associated with this node and its descendants.#### .ownErrors
Property that is an array of
HTMLParseErrors associated with only this node (not its descendants).#### .tagName
On
TAG and CLOSETAG type nodes, this is a string of the lowercased tag name.#### .attributes
On
TAG type nodes, this is an array of ATTRIBUTE nodes that belong to the tag.#### .closingTag
On
TAG type nodes, this is a CLOSETAG` node, if a closing tag for this node was found.