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
Class documentation
Refer to the documentation.
Utils
TBD
Changelog
Current
Added
Utils
TBD
Index
External modules
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
Variables
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
ibm-wch-sdk-rendition-utils > "utils/rendition.utils" > Dimension
Interface: Dimension
Exposes the concept of a dimension
Hierarchy
Dimension
Index
Properties
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
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
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