Module: lib/util

Methods

(static) createFilter(jsonQueryopt) → {function}

Turns the given JSON object into a filter function.

Parameters:
Name Type Attributes Description
jsonQuery object <optional>

An object specifying properties and values that an object has to match in order to pass the filter. If omitted, or if the object has no keys, any object will pass the generated filter.
Source:
Returns:

the generated filter function, accepts an object as argument and returns true if it passes the filter and false otherwise.

Type
function

(static) defaultHandler(callbackopt) → {function}

Creates a default error handler function and returns it.

Parameters:
Name Type Attributes Description
callback function <optional>

possibly existing callback
Source:
Returns:

the callback parameter if it is a function, and otherwise a function that treats its first argument as an error object and throws it if it is defined.

Type
function

(static) defineLinkedPropertiesFromMap(obj, propMapDict, dictKey, srcPropopt)

Defines properties on the given object according to property specifications found in a map. If a property specification defines setter behavior, the object is an event emitter, and a property set changes the value, the object will emit an 'update' event, with 4 parameters: the object, the name of the property, the new value, and the previous value.

Parameters:
Name Type Attributes Description
obj object

the object on which to define the properties
propMapDict object

a dictionary of property specification maps. A property specification map is keyed by the names of the properties to define. The value (the property specification) is an array. Its first element is the name of the property in another object (see srcProp) from which to derive the value, or undefined if there is no simple source property. The second element is a transform function to apply for the getter, which is passed the source property value (if the first element gives a source property). The third element is the same for the setter. If getter or setter transforms are undefined, the property will not have a getter or setter, respectively.
dictKey string

the key to the dictionary under which the property specification map is found. If the specification map is a string, it will be used recursively to look up the specification map.
srcProp string <optional>

the name of the property storing the object from which property values will be linked. Default is 'data'.
Since:
  • 0.7.0
Source:

(static) defineLinkedProperty(obj, prop, srcPropopt, readOnlyopt)

Defines a property on the given object whose value will be linked to that of the property of another object. If the object is an event emitter, a property set that changes the value will emit an 'update' event for the object with 3 parameters, the object, the name of the property, and the new value.

Parameters:
Name Type Attributes Description
obj object

the object for which to define the property
prop string | Array.<string>

the name of the property to define, or an array of two elements, namely the name of the property to define, and the name of the property to link to
srcProp string <optional>

the name of the property that stores the source object (from which values will be linked). Default is 'data'.
readOnly boolean <optional>

whether the property is to be read-only, defaults to false.
Since:
  • 0.7.0
Source:

(static) defineOnChangeProperty(obj, propNameopt, eventopt)

Defines a property with the given name for the given object using a getter/setter combination. If the objset is an event emitter, the object will emit an event of the given name if a property set changes the value of the property.

Parameters:
Name Type Attributes Description
obj object

the object for which to define the property
propName string <optional>

the name of the property, defaults to 'data'
event event <optional>

the name of the event to emit, defaults to 'data'
Since:
  • 0.7.0
Source:

(static) FILETIMEtoDate(filetime) → {number}

Converts from Windows FILETIME (100 nanosecond intervals since January 1, 1601 (UTC)) to JavaScript Date (milliseconds since January 1, 1970 (UTC)).

Parameters:
Name Type Description
filetime number

the Windows FILETIME value to convert
Source:
Returns:

the corresponding milliseconds since the epoch

Type
number

(static) retryUntil(action, success, optionsopt)

Retries the given (assumed to be asynchronous) action until it succeeds, or throws a general error.

Parameters:
Name Type Attributes Description
action function

the action to retry, expected to return a promise
success function

A function that is passed the value to which action() resolves, and the current attempt (a number). Should either return true (indicating success), throw an instance of WirelessTagPlatform.OperationIncompleteError to indicate an unsuccessful attempt that should be retried, or throw another error to terminate retry attempts.
options object <optional>

options to be passed on to retryPromise.
Source:
Returns:

the value to which the action resolves

(static) round(number, precision)

Similar to Math.round() but rounds to given precision of decimal places.

Parameters:
Name Type Description
number number

the number to round
precision number

the precision to round to in decimal places
Source: