Difference between revisions of "Avoiding Casting"
From PowerUI
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| − | === Element === | + | === Node (Element, HtmlElement etc) === |
{| class="wikitable" | {| class="wikitable" | ||
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! What it does | ! What it does | ||
|- | |- | ||
| − | | | + | | item(x) |
| − | | | + | | htmlItem(x) |
| Node to HtmlElement | | Node to HtmlElement | ||
| + | |} | ||
| + | |||
| + | === HTMLCollection === | ||
| + | |||
| + | ''Poorly named by the specification; these are collections of Element objects.'' | ||
| + | |||
| + | {| class="wikitable" | ||
| + | |- | ||
| + | ! Standard name | ||
| + | ! Convenience name | ||
| + | ! What it does | ||
| + | |- | ||
| + | | item(x) | ||
| + | | htmlItem(x) | ||
| + | | Element to HtmlElement | ||
|} | |} | ||
Latest revision as of 22:19, 9 February 2017
PowerUI 2 has a standardised DOM. That means that methods like getElementById return an Element rather than the more useful HtmlElement, which results in a lot of casting that previously wasn't required.
Contents
Why does it happen at all?
HTML5 can have content like SVG and MathML embedded within it; an SvgElement is not a HtmlElement. However, the vast majority of the time, you'll be interacting with a HtmlElement (and on the web, Javascript hides this from you).
Convenience functions
If you find an instance where a convenience function would be useful, please let us know!
Document
(these ones have the bonus of being a little shorter too - just omit the word Element from the standard Web API)
| Standard name | Convenience name | What it does |
|---|---|---|
| getElementById | getById | Element to HtmlElement |
| getElementByTagName | getByTagName | Element to HtmlElement |
| getElementByAttribute | getByAttribute | Element to HtmlElement |
Event
| Standard name | Convenience name | What it does |
|---|---|---|
| target | htmlTarget | Element to HtmlElement |
Node (Element, HtmlElement etc)
| Standard name | Convenience name | What it does |
|---|---|---|
| parentNode | htmlParentNode | Node to HtmlElement |
| document | htmlDocument | Document to HtmlDocument |
NodeList
E.g. childNodes uses these
| Standard name | Convenience name | What it does |
|---|---|---|
| item(x) | htmlItem(x) | Node to HtmlElement |
HTMLCollection
Poorly named by the specification; these are collections of Element objects.
| Standard name | Convenience name | What it does |
|---|---|---|
| item(x) | htmlItem(x) | Element to HtmlElement |
