ibm-wch-sdk-rendition-utils

Exposes framework independent APIs to support the implementation of ibm-wch-sdk-ng and similar SDK.

Details

Refer to the documentation.

Changes

CHANGELOG

Class documentation

Refer to the documentation.

Utils

TBD

Changelog

Current

Added

• Initial version

Utils

TBD

Index

External modules

• "index"
• "utils/rendition.utils"

ibm-wch-sdk-rendition-utils > "index"

External module: "index"

Index

ibm-wch-sdk-rendition-utils > "utils/rendition.utils"

External module: "utils/rendition.utils"

Index

Interfaces

• Dimension
• RenditionBean
• ScaledImage

Variables

• LOGGER
• RENDITION_REGEXP
• _mathFloor
• _mathRound
• jsonStringify

Functions

• _appendQueryString
• _approx
• _binaryIndexOf
• _clip
• _compareByAspect
• _compareByWidth
• _compareByWidthAndHeight
• _compareNumbers
• _createDimension
• _createRenditionBean
• _equalsWidth
• _findBestAspects
• _findBestWidth
• _findByWidth
• _getDecodedQueryString
• _getRendition
• _getSourceSet
• _parseNumber
• _round

Variables

<Const> LOGGER

● LOGGER: "RenditionDirective" = "RenditionDirective"

Defined in utils/rendition.utils.ts:4

<Const> RENDITION_REGEXP

● RENDITION_REGEXP: RegExp = /resize=(\d+)(?:px)?:(\d+)(?:px)?&crop=(\d+)(?:px)?:(\d+)(?:px)?;(\d+)(?:px)?,(\d+)(?:px)?/

Defined in utils/rendition.utils.ts:257

Regular expression to detect the renditions settings. Make sure to not use the 'g' flag!

<Const> _mathFloor

● _mathFloor: floor = Math.floor

Defined in utils/rendition.utils.ts:48

<Const> _mathRound

● _mathRound: round = Math.round

Defined in utils/rendition.utils.ts:49

<Const> jsonStringify

● jsonStringify: stringify = JSON.stringify

Defined in utils/rendition.utils.ts:6

Functions

_appendQueryString

▸ _appendQueryString(aBaseUrl: string, aQueryString: string): string

Defined in utils/rendition.utils.ts:59

Appends a query string to a base URL that may or may not have a query part. If it has a query, the previous query is removed

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aBaseUrl | string | current base URL | | aQueryString | string | string to append |

Returns: string the resulting URL

_approx

▸ _approx(aNumber: number): number

Defined in utils/rendition.utils.ts:73

Approximate a floating number to a fixed number of decimals

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aNumber | number | number to approximate |

Returns: number the approximated number

_binaryIndexOf

▸ _binaryIndexOf<T,K>(aSearchElement: K, aArray: T[], aCmp: function): number

Defined in utils/rendition.utils.ts:110

Executes a binary search for an element

Type parameters:

T

K

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aSearchElement | K | element to look for | | aArray | T[] | array to search | | aCmp | function | comparision function |

Returns: number the index

_clip

▸ _clip(aValue: number, aMin: number, aMax: number): number

Defined in utils/rendition.utils.ts:304

Clips a value against the given boundaries

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aValue | number | the value to clip | | aMin | number | the min value | | aMax | number | the max value |

Returns: number the clipped value

_compareByAspect

▸ _compareByAspect(aLeft: RenditionBean, aRight: RenditionBean): number

Defined in utils/rendition.utils.ts:150

Compares renditions by aspect

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aLeft | RenditionBean | left value to compare | | aRight | RenditionBean | right value to compare |

Returns: number comparison result

_compareByWidth

▸ _compareByWidth(aLeft: * Rendition | RenditionBean, aRight: * Rendition | RenditionBean): number

Defined in utils/rendition.utils.ts:161

Compares renditions by width

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aLeft | Rendition | RenditionBean| left value to compare | | aRight | Rendition | RenditionBean| right value to compare |

Returns: number comparison result

_compareByWidthAndHeight

▸ _compareByWidthAndHeight(aLeft: * Rendition | RenditionBean, aRight: * Rendition | RenditionBean): number

Defined in utils/rendition.utils.ts:173

Compares renditions by width

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aLeft | Rendition | RenditionBean| left value to compare | | aRight | Rendition | RenditionBean| right value to compare |

Returns: number comparison result

_compareNumbers

▸ _compareNumbers(aLeft: number, aRight: number): number

Defined in utils/rendition.utils.ts:139

Safe number comparison

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aLeft | number | left value to compare | | aRight | number | right value to compare |

Returns: number comparison result

_createDimension

▸ _createDimension(aWidth: number, aHeight: number): Dimension

Defined in utils/rendition.utils.ts:16

Constructs a dimensions object based on width and height

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aWidth | number | the width | | aHeight | number | the height |

Returns: Dimension the dimension object

_createRenditionBean

▸ _createRenditionBean(aTargetAspect: number, aRendition: Rendition): RenditionBean

Defined in utils/rendition.utils.ts:85

Constructs the rendition bean based on the actual rendition

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aTargetAspect | number | desired target aspect | | aRendition | Rendition | the rendition |

Returns: RenditionBean the bean

_equalsWidth

▸ _equalsWidth(aLeft: * Rendition | RenditionBean, aRight: * Rendition | RenditionBean): boolean

Defined in utils/rendition.utils.ts:185

Tests if the width of two renditions is equal

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aLeft | Rendition | RenditionBean| left rendition | | aRight | Rendition | RenditionBean| right rendition |

Returns: boolean true if equal

_findBestAspects

▸ _findBestAspects(aRenditions: RenditionBean[], aLogger: Logger): RenditionBean[]

Defined in utils/rendition.utils.ts:207

Returns a list of renditions with the best matching aspect ratio

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aRenditions | RenditionBean[] | the renditions | | aLogger | Logger | the logger |

Returns: RenditionBean[] the renditions with the best matching aspect ratio

_findBestWidth

▸ _findBestWidth(aWidth: number, aRenditions: RenditionBean[], aLogger: Logger): RenditionBean | undefined

Defined in utils/rendition.utils.ts:231

Find the rendition with the best width, i.e. the closest width that is larger than the given width

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aWidth | number | desired width | | aRenditions | RenditionBean[] | renditions | | aLogger | Logger | the logger |

Returns: RenditionBean | undefined

the selected rendition

_findByWidth

▸ _findByWidth(aLeft: number, aRight: * Rendition | RenditionBean*): number

Defined in utils/rendition.utils.ts:196

Compares renditions by width

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aLeft | number | left value to compare | | aRight | Rendition | RenditionBean| right value to compare |

Returns: number comparison result

_getDecodedQueryString

▸ _getDecodedQueryString(aUrl: string): string | undefined

Defined in utils/rendition.utils.ts:265

Checks if the URL has a query string and decodes it if so.

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aUrl | string | the URL |

Returns: string | undefined

the decoded query string or undefined

_getRendition

▸ _getRendition(aDstWidth: number, aDstHeight: number, aImage: Image, aLogger: Logger): ScaledImage

Defined in utils/rendition.utils.ts:323

Builds a query string for the Akamai rendition service such that the resulting image matches the desired dimensions. The algorithm first finds the renditions with the best matching aspect ratio. Out of the result set it then selects the nearest rendition that is large or equal in size, because that most likely represents the desired excerpt best. It then fixes the aspect ration and computes the new transform.

In case the image would be scaled up, we return the identity scaling and let the browser scale the image.

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aDstWidth | number | desired image width | | aDstHeight | number | desired image height | | aImage | Image | the image | | aLogger | Logger | the logger |

Returns: ScaledImage the URL string

_getSourceSet

▸ _getSourceSet(aImage: Image, aOrigin: string): string

Defined in utils/rendition.utils.ts:432

Computes the source set from the available renditions

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aImage | Image | the image | | aOrigin | string | the origin |

Returns: string the source set

_parseNumber

▸ _parseNumber(aValue: string): number

Defined in utils/rendition.utils.ts:282

Parses a string into a number

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aValue | string | the value to parse |

Returns: number the decoded string

_round

▸ _round(aValue: number): number

Defined in utils/rendition.utils.ts:292

Rounding function

Parameters:

| Param | Type | Description | | ------ | ------ | ------ | | aValue | number | the value to round |

Returns: number the rounded value

Utils

TBD

Index

External modules

• "index"
• "utils/rendition.utils"

ibm-wch-sdk-rendition-utils > "utils/rendition.utils" > Dimension

Interface: Dimension

Exposes the concept of a dimension

Hierarchy

Dimension

Index

Properties

• h
• w

Properties

h

● h: number

Defined in utils/rendition.utils.ts:28

w

● w: number

Defined in utils/rendition.utils.ts:27

ibm-wch-sdk-rendition-utils > "utils/rendition.utils" > RenditionBean

Interface: RenditionBean

Hierarchy

RenditionBean

Index

Properties

• aspect
• diff
• height
• rendition
• width

Properties

aspect

● aspect: number

Defined in utils/rendition.utils.ts:41

diff

● diff: number

Defined in utils/rendition.utils.ts:44

height

● height: number

Defined in utils/rendition.utils.ts:43

rendition

● rendition: Rendition

Defined in utils/rendition.utils.ts:40

width

● width: number

Defined in utils/rendition.utils.ts:42

ibm-wch-sdk-rendition-utils > "utils/rendition.utils" > ScaledImage

Interface: ScaledImage

Hierarchy

ScaledImage

Index

Properties

• container
• image
• img
• url

Properties

container

● container: Dimension

Defined in utils/rendition.utils.ts:35

image

● image: Image

Defined in utils/rendition.utils.ts:33

img

● img: Dimension

Defined in utils/rendition.utils.ts:34

url

● url: string

Defined in utils/rendition.utils.ts:36