@mangar2/topicmatch NPM

Abstract

Global functions

_deletePatternRec

_deletePatternRec (topicChunks, node, index)

Recursively removes a pattern ( exact match ) from the tree

_deletePatternRec Parameters

Name	Type	Attribute	Default	Description
`topicChunks`	`Array.<string>`			topic chunks to search for
`node`	`Object`			current node in the pattern tree
`index`	`number`	optional	0	current index ( depth ) in the topic array

_getBestMatchRec

_getBestMatchRec (isBetter, topicChunks, node, index)

Searches for a topic in a pattern tree , returns the best match ( match with highest value )

_getBestMatchRec Parameters

Name	Type	Attribute	Default	Description
`isBetter`	`function(a, b`			returns true , if a is better than b
`topicChunks`	`Array.<string>`			topic chunks to search for
`node`	`Object`			current node in the pattern tree
`index`	`number`	optional	0	current index ( depth ) in the topic array

_getFirstMatchRec

_getFirstMatchRec (topicChunks, node, index)

Searches for a topic in a pattern tree , returns the first match

_getFirstMatchRec Parameters

Name	Type	Attribute	Default	Description
`topicChunks`	`Array.<string>`			topic chunks to search for
`node`	`Object`			current node in the pattern tree
`index`	`number`	optional	0	current index ( depth ) in the topic array

_max

_max (isBetter, a, b)

Gets the maximum of two elements that are either a number or undefined . Undefined values are ignored _max ( undefined , undefined ) = undefined _max ( undefined , b ) = b

_max Parameters

Name	Type	Description
`isBetter`	`function(a, b`	returns true , if a is better than b
`a`	`number, undefined`	first element
`b`	`number, undefined`	second element

addPattern

addPattern (pattern, value)

Adds a pattern to a pattern tree . The pattern has '/' as separator

addPattern Parameters

Name	Type	Attribute	Default	Description
`pattern`	`string`			pattern string with '/' as separator
`value`	`number`	optional	0	pattern value

deletePattern

deletePattern (pattern)

Delete a pattern from the tree

deletePattern Parameters

Name	Type	Description
`pattern`	`string`	pattern to delete

getBestMatch

getBestMatch (topic, isBetter)

Gets the first match of a topic

getBestMatch Parameters

Name	Type	Description
`topic`	`string`	topic to search for
`isBetter`	`function(a, b`	returns true , if a is better than b

getFirstMatch

getFirstMatch (topic)

Gets the first match of a topic

getFirstMatch Parameters

Name	Type	Description
`topic`	`string`	topic to search for

Class TopicMatch

new TopicMatch(pattern)

Contructs a new class Checks , if a topic matches a list of patterns . The pattern is bases on the MQTT pattern design . Every pattern has an associated value ( used for QoS in MQTT ) Topic structure slashes with strings in between : /string1/string2/string3/ . . . Pattern is like topic with the following whildcards : "+" and "#" . The "+" matches any string , the "#" matches the rest of the topic .

Example

const topicMatch = new TopicMatch()
topicMatch.addPattern('#', 0)
topicMatch.getFirstMatch('hello') // returns 0
topicMatch.removePattern('#')
topicMatch.addPattern('/+', 1)
topicMatch.getFirstMatch('hello') // returns undefined
topicMatch.getFirstMatch('/hello') // returns 1
topicMatch.getFirstMatch('/hello/world') // returns undefined

TopicMatch Parameters

Name	Type	Attribute	Default	Description
`pattern`	`Object, Array, string`	optional	{ }	pattern data structure { pattern : value , pattern : value , . . . }

TopicMatch Members

Name	Type	description
`topicPatternList`	`@type`	List containing all active pattern { pattern : QoS , . . . }

TopicMatch Methods

addPattern

addPattern (pattern, value)

Adds a pattern string to the patternlist ( if not already included )

addPattern Parameters

Name	Type	Attribute	Default	Description
`pattern`	`string, Array, Object`			single pattern or list of pattern
`value`	`any`	optional	0	value associated with the pattern

addPattern throws

Type	Description
`Error`	if pattern is not string or value is not provided

changePattern

changePattern (patternCommand)

Sets , adds and/or removes pattern .

changePattern Parameters

Name	Type	Description
`patternCommand`	`Object`	object with attributes "set , remove , add" and a pattern list

clear

clear ()

Clears the pattern tree

deletePattern

deletePattern (patternList)

Delete a pattern from the tree

deletePattern Parameters

Name	Type	Description
`patternList`	`Array, string`	string or array of strings containing patterns to delete

getBestMatch

getBestMatch (searchTopic, isBetter) => {any}

Gets the best value of all matching pattern according the compare function . If no compare function is provided , the values of the patterns are compared with the ">" operator