Fragment API¶

Fragments for XBlocks.

This code is in the Runtime layer.

class xblock.fragment.Fragment(content=None)¶

A fragment of a web page, for XBlock views to return.

A fragment consists of HTML for the body of the page, and a series of resources needed by the body. Resources are specified with a MIME type (such as “application/javascript” or “text/css”) that determines how they are inserted into the page. The resource is provided either as literal text, or as a URL. Text will be included on the page, wrapped appropriately for the MIME type. URLs will be used as-is on the page.

Resources are only inserted into the page once, even if many Fragments in the page ask for them. Determining duplicates is done by simple text matching.

add_content(content)¶

Add content to this fragment.

content is a Unicode string, HTML to append to the body of the fragment. It must not contain a <body> tag, or otherwise assume that it is the only content on the page.

add_css(text)¶: Add literal CSS to the Fragment.

add_css_url(url)¶: Add a CSS URL to the Fragment.

add_frag_resources(frag)¶

Add all the resources from frag to my resources.

This is used by an XBlock to collect resources from Fragments produced by its children.

frag is a Fragment.

The content from the Fragment is ignored. The caller must collect together the content into this Fragment’s content.

add_frags_resources(frags)¶

Add all the resources from frags to my resources.

This is used by an XBlock to collect resources from Fragments produced by its children.

frags is a sequence of Fragments.

The content from the Fragments is ignored. The caller must collect together the content into this Fragment’s content.

add_javascript(text)¶: Add literal Javascript to the Fragment.

add_javascript_url(url)¶: Add a Javascript URL to the Fragment.

add_resource(text, mimetype, placement=None)¶

Add a resource needed by this Fragment.

Other helpers, such as add_css() or add_javascript() are more convenient for those common types of resource.

text: the actual text of this resource, as a unicode string.

mimetype: the MIME type of the resource.

placement: where on the page the resource should be placed:

None: let the Fragment choose based on the MIME type.

“head”: put this resource in the <head> of the page.

“foot”: put this resource at the end of the <body> of the page.

add_resource_url(url, mimetype, placement=None)¶

Add a resource by URL needed by this Fragment.

Other helpers, such as add_css_url() or add_javascript_url() are more convenent for those common types of resource.

url: the URL to the resource.

Other parameters are as defined for add_resource().

body_html()¶

Get the body HTML for this Fragment.

Returns a Unicode string, the HTML content for the <body> section of the page.

content = None¶: The html content for this Fragment

foot_html()¶

Get the foot HTML for this Fragment.

Returns a Unicode string, the HTML content for the end of the <body> section of the page.

classmethod from_pods(pods)¶

Returns a new Fragment from a pods.

pods is a Plain Old Data Structure, a Python dictionary with keys content, resources, js_init_fn, and js_init_version.

head_html()¶

Get the head HTML for this Fragment.

Returns a Unicode string, the HTML content for the <head> section of the page.

initialize_js(js_func, json_args=None)¶

Register a Javascript function to initialize the Javascript resources.

js_func is the name of a Javascript function defined by one of the Javascript resources. As part of setting up the browser’s runtime environment, the function will be invoked, passing a runtime object and a DOM element.

static resource_to_html(resource)¶: Returns resource wrapped in the appropriate html tag for it’s mimetype.

resources¶: Returns list of unique FragmentResources by order of first appearance.

resources_to_html(placement)¶

Get some resource HTML for this Fragment.

placement is “head” or “foot”.

Returns a unicode string, the HTML for the head or foot of the page.

to_pods()¶

Returns the data in a dictionary.

‘pods’ = Plain Old Data Structure.

class xblock.fragment.FragmentResource(kind, data, mimetype, placement)¶

__getnewargs__()¶: Return self as a plain tuple. Used by copy and pickle.

__getstate__()¶: Exclude the OrderedDict from pickling

__repr__()¶: Return a nicely formatted representation string

data¶: Alias for field number 1

kind¶: Alias for field number 0

mimetype¶: Alias for field number 2

placement¶: Alias for field number 3