Page Contributions
Contents
Lets components, macros, and processors contribute content to the response HTML header and/or footer.
| Only available in the Site Engine |
Introduction
Some pages and applications require specific scripts to be available within the HTML response of a page, typically placed within a specific location of the markup such as in the <head> section, or close to the body end tag.
Example use cases are:
-
Let a part contribute JavaScript to the page’s
<head>section. -
Let a part contribute custom CSS to the
<head>of that page. -
A layout might add a JavaScript tracker to the end of the
<body>of the page.
Page contributions will only be triggered if the response type is text/html (which is the default) |
There are four positions in the result HTML where contributed content can be inserted:
- headBegin
-
After the
<head>opening tag. - headEnd
-
Before the
</head>closing tag. - bodyBegin
-
After the
<body>opening tag. - bodyEnd
-
Before the
</body>closing tag.
Usage
The component or controller must add a pageContributions property in the HTTP response object.
Sample controller return adding a script element to headEnd.
return {
body: '<p>Some markup</p>',
pageContributions: {
headEnd: [
"<script>My script</script>"
]
}
};Changing the headEnd to one of the other possible positions will affect where the code you contributed is merged in the response markup.
return {
"body": "<div>...</div>",
"pageContributions": {
"headEnd": "value",
"bodyEnd": [
"value1", "value2"
]
}
};-
Page Contributions are optional.
-
Contribution values are treated as plain text.
-
Values must be unique within each injection point, duplicates will be truncated.
-
If the target tag does not exist in the response body, the contribution will be ignored. I.e. if there is no
<head>tag, the contributions toheadBeginandheadEndwill be ignored. -
For consistency, all positions are automatically treated arrays in the aggregated response object, even if there is only a single value.
Contribution merging
Page contributions are merged into the response markup during a specific step in the site engine, called Contributions filter. It occurs after page processors and before the site filters.
| Duplicate page contributions will automatically be removed, so developers do not have to worry about this. |
