Using JavaScript

Usage

JavaScript expressions can be used to transform inputs, generate strings, manipulate content and access variables. Anything between ${} is interpolated as a Template string Everything between ${} must be on 1 line unless you use this approach.

Variables

Read about variables here

Functions

Aside from the standard JavaScript functions like String.toLowerCase() there are several built-in functions and a few libraries available.

Function	Description	Parameters	Example
arrayify	Converts a string or array into an array	str || [str]	arrayify("str") = ["str"] arrayify(["str","str2"]) = ["str","str2"]
bashEscape	Escapes a string for use between $'str' in Bash shells	str	"echo $'${bashEscape("It'sa me Mario")}'" = "echo $'It\'sa me Mario'"
cfn	Get the value from a CloudFormation stack. Since it is async, you must call it with await.	stack	(await cfn(`speedrun-federation-${stage}`)).outputs.HostedZoneId=Z2OJLYMUO9EFXC
acfn	Get the value from a CloudFormation stack. Wrapped version cfn so you don't need the await syntax.	stack, pathToValue	acfn(`speedrun-federation-${stage}`,'outputs.HostedZoneId')=Z2OJLYMUO9EFXC
dayjs	The day.js library	See docs	dayjs().format() = "2022-08-17T15:02:17-07:00"
encodeCloudWatchInsightsParam	Encodes a string for usages as a parameter in a Cloudwatch Insights url	str	encodeCloudWatchInsightsParam("/lambda/speedrun-federation") = "\*2flambda\*2fspeedrun-api"
encodeCloudWatchURL	Encodes a string for usages as a parameter in a Cloudwatch url	str	encodeCloudWatchuRL("/lambda/speedrun-federation") = "$252Faws$252Flambda$252Fspeedrun-federation-dev"
firstGroup	get the first matcher group of a regex	regex, str	firstGroup(/#(\w+)/,"#hashtag") = "hashtag"
firstNonNull	Return the first value that isn't undefined or null	...str	firstNonNull(null,undefined,"defined") = "defined"
includesSearch	Return all elements that include str	str, ["str","str2"]	includesSearch("a",["ab","ba","cd"]) = ["ab","ba"]
JSON5	The JSON5 library	See docs	JSON5.parse('{name:"David"}') = {name:"David"}
lastLine	Return the last line of str	str	lastLine('A long time ago\nIn a faraway land') = "In a faraway land"
nullSafe	Returns a empty {} if o is undefined	o	nullSafe(undefined) = {} nullSafe("str") = "str"
prefixSearch	Return all elements that are prefixed with str	str, ["str","str2"]	includesSearch("a",["ab","ba","cd"]) = ["ab"]
prepend	Return all elements prepended with str	str, ["str1","str2",...]	prepend('a',["b","c"]) = ["ab","ac"]
prettyJSON	Formats json	o, spaces=4	prettyJSON({region:"us-east-1", account:"10203456789"}) = {   "region": "us-east-1",   "account": "10203456789" }
regexSearch	Return all elements that are match regex	regex, ["str","str2"]	regexSearch(/a/,["ab","ba","cd"]) = ["ab","ba"]
srTimestamp	Prompt user for recorded time interval and turn it into url form	n/a	srTimestamp() = "end~'2022-08-06T17:45:42.557Z~start~'2022-08-06T17:42:35.544Z~timeType~'ABSOLUTE~tz~'UTC"
stringify	Converts o to a JavaScript escaped string	o	stringify({"region":"us-west-2"}) = "{\"region\":\"us-west-2\"}"
_	The lodash library	See docs	_.camelCase('Two Words') = "twoWords"

Writing your own functions

You can define your own functions in your srConfig. Functions must be prefixed with function: The body must be converted to a one line JSON string.

If there is only one argument, reference it with str.

"function:stripNewLines" : {
    "body" : "return str.replaceAll('\\n','')"
}

To define a function with multiple arguments specify args containing an array of their names:

"function:concatenate" : {
    "args" : ["str1","str2"],
    "body" : "return str1 + str2"
}

Multiline JavaScript

This is a sample of how to use multiline Javascript. You can use `` (Template string syntax) within a ${}. Click the code tab to see exact code.

#copy
~~~multiline=Multiline? {"type":"checkbox","suppress":"true"}~~~
${multiline?`This
is
some
beautiful multiline content`:'One line'}

Default values

If you want to use a default only if a variable isn't defined use this syntax: ${typeof start === 'undefined' ? '-3600' : start}