Asset

Asset

An asset object represents a single node in an AssetGraph, but can be used and manipulated on its own outside the graph context.

Constructor

new Asset(config, assetGraph)

Source:

Create a new Asset instance.

Most of the time it's unnecessary to create asset objects directly. When you need to manipulate assets that already exist on disc or on a web server, the loadAssets and populate transforms are the easiest way to get the objects created. See the section about transforms below.

Note that the Asset base class is only intended to be used to represent assets for which there's no specific subclass.

Parameters:
Name Type Description
config AssetConfig

Configuration for instantiating an asset
assetGraph AssetGraph

Mandatory AssetGraph instance references

Members

baseName :String

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The file name for the asset, excluding the extension. It is automatically kept in sync with the url, but preserved if the asset is inlined or set to a value that ends with a slash.

If updated, the url of the asset will also be updated.

Type:
  • String

contentType :String

Source:
Default Value:
  • 'appliction/octet-stream'

The Content-Type (MIME type) of the asset.

Type:
  • String

dataUrl :String

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The data:-url of the asset for inlining

Type:
  • String

defaultExtension :String

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The default extension for the asset type, prepended with a dot, eg. .html, .js or .png

Type:
  • String

extension :String

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The file name extension for the asset (String). It is automatically kept in sync with the url, but preserved if the asset is inlined or set to a value that ends with a slash.

If updated, the url of the asset will also be updated.

The extension includes the leading dot and is thus kept in the same format as require('path').extname and the basename command line utility use.

Type:
  • String

externalRelations :Array.<Relation>

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The subset of outgoing Relations that point to external (non-inlined) Assets

Type:

fileName :String

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The file name for the asset. It is automatically kept in sync with the url, but preserved if the asset is inlined or set to a value that ends with a slash.

If updated, the url of the asset will also be updated.

Type:
  • String

hostname :String

Source:

The hostname part of a URL protocol://username:password@<hostname>:port/

Type:
  • String

incomingRelations :Array.<Relation>

Source:

Get/set the relations pointing to this asset

Caveat: Setting Does not remove/detach other relations already pointing at the asset, but not included in the array, so it's not strictly symmetric with the incomingRelations getter.

Type:

(constant) isAsset :Boolean

Source:
Default Value:
  • true

Boolean Property that's true for all Asset instances. Avoids reliance on the instanceof operator.

Type:
  • Boolean

isExternalizable :Boolean

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Default Value:
  • true

Whether the asset occurs in a context where it can be made external. If false, the asset will stay inline. Useful for "always inline" assets pointed to by HtmlConditionalComment, HtmlDataBindAttribute, and HtmlKnockoutContainerless relations. Override when creating the asset.

Type:
  • Boolean

isInline :Boolean

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Determine whether the asset is inline (shorthand for checking whether it has a url).

Type:
  • Boolean

isLoaded :Boolean

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The loaded state of the Asset

Type:
  • Boolean

lastKnownByteLength :Number

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Get the last known byt length of the Asset

Doesn't force a serialization of the asset if a value has previously been recorded.

Type:
  • Number

md5Hex :String

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Get the current md5 hex of the asset.

Type:
  • String

(nullable) nonInlineAncestor :Asset

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Get the first non-inline ancestor asset by following the incoming relations, ie. the first asset that has a url. Returns the asset itself if it's not inline, and null if the asset is inline, but not in an AssetGraph.

Type:

origin :String

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The origin of the asset, protocol://host Corresponds to new URL(...).origin

For inlined assets, this will contain the origin of the first non-inlined ancestor

Type:
  • String

outgoingRelations :Array.<Relation>

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Get/set the outgoing relations of the asset.

Type:

parseTree :Oject

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Some asset classes support inspection and manipulation using a high level interface. If you modify the parse tree, you have to call asset.markDirty() so any cached serializations of the asset are invalidated.

These are the formats you'll get:

Html and Xml: jsdom document object (https://github.com/tmpvar/jsdom).

Css CSSOM CSSStyleSheet object (https://github.com/NV/CSSOM).

JavaScript estree AST object (via acorn).

Json Regular JavaScript object (the result of JSON.parse on the decoded source).

CacheManifest A JavaScript object with a key for each section present in the manifest (CACHE, NETWORK, REMOTE). The value is an array with an item for each entry in the section. Refer to the source for details.

Type:
  • Oject

password :String

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The password part of a URL protocol://username:<password>@hostname:port/

Type:
  • String

path :String

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The path of the asset relative to the AssetGraph root. Corresponds to a new URL(...).pathName

If updated, the url of the asset will also be updated.

Type:
  • String

port :Number

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The port part of a URL protocol://username:password@hostname:<port>/

Type:
  • Number

protocol :String

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The protocol part of a URL <protocol:>//username:password@hostname:port/. Includes trailing :

Type:
  • String

query :String

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The query parameters part of the Assets URL.

Can be set with a String or Object, but always returns String in the getters

Type:
  • String

rawSrc :Buffer

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Get or set the raw source of the asset.

If the internal state has been changed since the asset was initialized, it will automatically be reserialized when this property is retrieved.

Type:
  • Buffer
Example
const htmlAsset = new AssetGraph().addAsset({
  type: 'Html',
  rawSrc: new Buffer('<html><body>Hello!</body></html>')
});
htmlAsset.parseTree.body.innerHTML = "Bye!";
htmlAsset.markDirty();
htmlAsset.rawSrc.toString(); // "<html><body>Bye!</body></html>"

type :String

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The assets defined or inferred type

Type:
  • String

url :String

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Get or set the absolute url of the asset.

The url will use the file: schema if loaded from disc. Will be falsy for inline assets.

Type:
  • String

urlOrDescription :String

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A Human readable URL or Asset description if inline. Paths for file:// URL's are kept relative to the current working directory for easier copy/paste if needed.

Type:
  • String

username :String

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The username part of a URL protocol://<username>:password@hostname:port/

Type:
  • String

Methods

addRelation(relation, positionopt, adjacentRelationopt)

Source:

Attaches a Relation to the Asset.

The ordering of certain relation types is significant (HtmlScript, for instance), so it's important that the order isn't scrambled in the indices. Therefore the caller must explicitly specify a position at which to insert the object.

Parameters:
Name Type Attributes Default Description
relation Relation

The Relation to attach to the Asset
position String <optional>
 'last'

"first", "last", "before", or "after"
adjacentRelation Relation <optional>

The adjacent relation, mandatory if the position is "before" or "after"

clone(incomingRelations) → {Asset}

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Clone this asset instance and add the clone to the graph if this instance is part of a graph. As an extra service, optionally update some caller-specified relations to point at the clone.

If this instance isn't inline, a url is made up for the clone.

Parameters:
Name Type Description
incomingRelations Array.<Relation> | Relation

(optional) Some incoming relations that should be pointed at the clone.
Returns:

The cloned asset.

Type
Asset

externalize()

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Externalize an inlined Asset.

This will create an URL from as many available URL parts as possible and auto generate the rest, then assign the URL to the Asset

findOutgoingRelationsInParseTree() → {Array.<Relation>}

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Parse the Asset for outgoing relations and return them.

Returns:

The Assets outgoing Relations

Type
Array.<Relation>

(async) load() → {Promise.<Asset>}

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Load the Asset

Returns a promise that is resolved when the asset is loaded. This is Asset's only async method, as soon as it is loaded, everything can happen synchronously.

Usually you'll want to use transforms.loadAssets, which will handle this automatically.

Returns:

The loaded Asset

Type
Promise.<Asset>

markDirty() → {Asset}

Source:

Sets the dirty flag of the asset, which is the way to say that the asset has been manipulated since it was first loaded (read from disc or loaded via http). For inline assets the flag is set if the asset has been manipulated since it was last synchronized with (copied into) its containing asset.

For assets that support a text or parseTree property, calling markDirty() will invalidate any cached serializations of the asset.

Returns:

The asset itself (chaining-friendly)

Type
Asset

populate()

Source:

Go through the outgoing relations of the asset and add the ones that refer to assets that are already part of the graph. Recurses into inline assets.

You shouldn't need to call this manually.

removeRelation(relation) → {Asset}

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Remove an outgoing Relation from the Asset by reference

Parameters:
Name Type Description
relation Relation

Outgoing Relation
Returns:

The Asset itself

Type
Asset

replaceWith(newAsset) → {Asset}

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Replace the asset in the graph with another asset, then remove it from the graph.

Updates the incoming relations of the old asset to point at the new one and preserves the url of the old asset if it's not inline.

Parameters:
Name Type Description
newAsset Asset

The asset to put replace this one with.
Returns:

The new asset.

Type
Asset

toString() → {String}

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Get a brief text containing the type, id, and url (if not inline) of the asset.

Returns:

The string, eg. "[JavaScript/141 file:///the/thing.js]"

Type
String

unload()

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Unload the asset body. If the asset is in a graph, also remove the relations from the graph along with any inline assets. Also used internally to clean up before overwriting .rawSrc or .text.