, (*1)
arc/html
This component provides a unified html parser and writer. The writer allows for readable and correct html in code, not using templates. The parser is a wrapper around both DOMDocument and SimpleXML., (*2)
The parser and writer also work on fragments of HTML. The parser also makes sure that the output is identical to the input.
When converting a node to a string, \arc\html will return the full html string, including tags. If you don't want that, you can always access the 'nodeValue' property to get the original SimpleXMLElement., (*3)
Finally the parser also adds the ability to use basic CSS selectors to find elements in the HTML., (*4)
use \arc\html as h;
$htmlString = h::doctype()
.h::html(
h::head(
h::title('Example site')
),
h::body(
['class' => 'homepage'],
h::h1('An example site')
)
);
$html = \arc\html::parse($htmlString);
$title = $html->head->title->nodeValue; // SimpleXMLElement 'Example site'
$titleTag = $html->head->title; // <title>Example site</title>
CSS selectors
$title = current($html->find('title'));
The find() method always returns an array, which may be empty. By using current() you get the first element found, or null if nothing was found., (*5)
The following CSS selectors are supported:, (*6)
-
tag1 tag2
This matches tag2 which is a descendant of tag1.
-
tag1 > tag2
This matches tag2 which is a direct child of tag1.
-
tag:first-child
This matches tag only if its the first child.
-
tag1 + tag2
This matches tag2 only if its immediately preceded by tag1.
-
tag1 ~ tag2
This matches tag2 only if it has a previous sibling tag1.
-
tag[attr]
This matches tag if it has the attribute attr.
-
tag[attr="foo"]
This matches tag if it has the attribute attr with the value foo in its value list.
-
tag#id
This matches any tag with id id.
-
#id
This matches any element with id id.
-
tag.class-name
Matches any tag with a class class-name.
-
.class-name
Matches any element with a class class-name.
SimpleXML
The parsed HTML behaves almost identical to a SimpleXMLElement, with the exceptions noted above. So you can access attributes just like SimpleXMLElement allows:, (*7)
$class = $html->html->body['class'];
$class = $html->html->body->attributes('version');
You can walk through the node tree:, (*8)
$title = $html->html->head->title;
Any method or property available in SimpleXMLElement is included in \arc\html parsed data., (*9)
DOMElement
In addition to SimpleXMLElement methods, you can also call any method and most properties available in DOMElement., (*10)
$class = $html->html->body->getAttributes('class');
$title = current($html->getElementsByTagName('title'));
Parsing fragments
The arc\html parser also accepts partial HTML content. It doesn't require a single root element., (*11)
$htmlString = <<< EOF
<li>
<a href="anitem/">An item</a>
</li>
<li>
<a href="anotheritem/">Another item</a>
</li>
EOF;
$html = \arc\html::parse($htmlString);
$links = $html->find('a');
And when you convert the html back to a string, it will still be a partial HTML fragment., (*12)
If you parse a single HTML tag, other than <html>, you must still reference this element to access it:, (*13)
$htmlString = <<< EOF
<ul>
<li>
<a href="anitem/">An item</a>
</li>
<li>
<a href="anotheritem/">Another item</a>
</li>
</ul>
EOF;
$html = \arc\html::parse($htmlString);
$ul = $html->ul;
Why use this instead of DOMDocument or SimpleXML?
arc\html::parse has the following differences:, (*14)
- When converted to string, it returns the original HTML, without additions you didn't make.
- You can use it with partial HTML fragments.
- No need to remember calling importNode() before appendChild() or insertBefore()
- No need to switch between SimpleXML and DOMDocument, because you need that one method only available in the other API.
- When returning a list of elements, you always get a simple Array, not a magic NodeList.
In addition arc\html doubles as a simple way to generate valid and indented HTML, with readable and self-validating code., (*15)
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