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Home > Guides > Cloud Workflow Developer Guide > Functions

Functions

 

 

Table of Contents Sections
  1. Functions Overview
  2. Collections Management
    1. find($type, $name or $hash[, $revision])
    2. size($array, $hash, $string or @collection)
    3. first($array or @collection) and last($array or @collection)
    4. sort($array or @collection[, $field][, $order])
    5. contains?($array or @collection, elements)
    6. empty?($array or @collection)
    7. any?($array[, $value_or_regexp])
    8. all?($array[, $value_or_regexp])
    9. select($array or @collection, $hash)
    10. unique($array or @collection)
  3. Resource Management
    1. provision(@declaration)
    2. delete(@resource)
  4. Boolean Logic
    1. equals?($left or @left, $right or @right)
    2. logic_and($left, $right) and logic_or($left, $right)
    3. logic_not($value​)
  5. Data Conversion
    1. to_s($value)
    2. to_n($value)
    3. to_b($value)
    4. to_d($value)
    5. to_a($value)
    6. to_object(@declaration or @collection) 
    7. to_json($value)
    8. from_json($value)
  6. Process Information
    1. self()
    2. task_name()
    3. tasks()
    4. task_status($task_name)
  7. Data Introspection
    1. type(object)
    2. inspect(object)
  8. String Manipulation
    1. split($string, $separator_or_regexp)
    2. join($array[, $separator])
  9. HTTP/HTTPS Functions
    1. General Information
      1. Making Requests
      2. Common Parameters for HTTP/S functions
      3. HTTP/S Function Responses
  10. Miscellaneous
    1. now()
    2. uuid()
    3. sleep($duration)
    4. sleep_until(expression)
    5. sleep_while(expression)
    6. keys($hash)
    7. values($hash)
    8. map($mapping_name, $key_name, $value_name)
    9. xpath($xml_string, $xpath)

Functions Overview

Functions are built-in operations that execute inside the engine. They provide various helpers to address needs like retrieving the current time, generating random numbers, sorting collections and arrays, etc. Functions may operate on values and/or on reference collections and return values and/or reference collections. Arguments passed to functions are read-only. For example, the sort() function will return the result of the sort rather than modify the argument. Functions use the lower_case() notation.

Collections Management

The first category of functions relate to managing resource collections and arrays of values.

find($type, $name or $hash[, $revision])

This function is syntactic sugar around the resource type get() action. It is the equivalent of calling the get() action with the given filters and returning the first resource that matches. Filters are specified with a hash or with a string and optional integer. If a string is specified then it is equivalent to a having a hash with a key name and the associated value (i.e. by default filter on name). If a integer is specified then is it equivalent to having a hash with a key revision. So:

@servers = find("servers", "default")
@servers = find("servers", { name: "default" })

are equivalent to:


@servers = first(rs.servers.get(filter: ["name==default"]))

and


@server_template = find("server_templates", "MySQL Database Manager", 137)
@server_template = find("server_templates", { name: "MySQL Database Manager", revision: 137 })

are equivalent to:


@server_template = first(rs.server_templates.get(filter: ["name==MySQL Database Manager","revision==137"]))

Arguments

Position Possible Values Required Default Value Comment
1 string yes none Resource type, e.g. "servers", "deployments", etc.
2

string

-or- 

hash

 yes none Resource name or filters
3 string or integer no none

Resource revision, if resource is versioned.

Not specifying a value for versioned resources returns all resources with the given type and name.

Result

A resource collection containing the first resource matching the given filter if any.

size($array, $hash, $string or @collection)

This function simply returns the size of the resource collection or array of values given as argument.

Arguments

Position Possible Values Required Default Value
1

resource collection
-or- 
array of values

-or-

hash of values

-or-

string

 yes none

Result

An integer representing the size of the given array, hash, string or collection.

first($array or @collection) and last($array or @collection)

These functions simply retrieve the first or last element of a resource collection or array of values.

Note: For resource collections, the result is a resource collection itself, consisting of a single resource. However, for an array of values, the result is a single value.

Arguments

The only argument is the collection from which the first or last element should be extracted.

Position Possible Values Required Default Value
1

resource collection -or- 
array of values

 yes none

Result

A resource collection if the argument is a resource collection or a value if the argument is an array of values.

Examples


$one = first([1, 2, 3]) # $one == 1

@servers = rs.deployments.get(filter: ["name==default"]).servers()
@first = first(@servers) # size(@first) == 1

sort($array or @collection[, $field][, $order])

The sort() function allows sorting resource collections and arrays of values. If sorting an array of values, then all values must be of the same type and the array must not contain null. The ordering follows the same logic as the comparison operators:

  • Numbers and datetime use the natural order (think of datetime in terms of seconds since the epoch for comparison)
  • Strings and arrays follow the lexicographical order
  • true > false

Hashes cannot be compared directly, instead the sort() function accepts an argument to specify recursively which key should be used for sorting. That same argument can be used on resource collections to specify which field should be used for sorting. If the field ends up being a hash, then recursively what key of the hash should be used. By default, sorting resource collections is done using the name field.

Arguments

Position Possible Values Required Default Value Comment
1

resource collection 
-or-
array of values

 yes none

collection to be sorted
2

string

only if collection is an array of hashes

"name" for resource collections

name of resource field used to order resource collections
-or-
name of key of hash to be used to order for array of hashes

the definition is recursive, each key being separated with the character /
3

"asc" or "desc"

 no

"asc"

Sorting order (ascendant or descendant)

Result

The result type is the same as the first argument: a resource collection or an array of values.

Examples

Sorting a resource collection by name:


@servers = rs.deployments.get(filter: "name==default").servers()
@sorted_servers = sort(@servers)

Sorting a collection of instances by their user data descending:


@instances = rs.deployments.get(filter: "name==default").server().current_instance()
@sorted_instances = sort(@instances, "settings/user_data", "desc")

Sorting an array of hashes (using a key called timestamp in this example):


$data = [{ "value": 42, "timestamp": d"1/1/2012 12:32" },
         { "value": 43, "timestamp": d"1/1/2012 16:31" }]
$sorted_data = sort($data, "timestamp")

contains?($array or @collection, elements)

This function checks whether all the elements of a given collection or a specific value are contained in another given collection. The elements may be in different order and they may appear a different number of times, but as long as all elements appear at least once, then the function returns true, otherwise it returns false.

Arguments

Position Possible Values Required Default Value Comment
1

resource collection
-or- 
array of values

 yes none

Container being tested
2

resource collection
-or- 
array of values

yes

none

Elements that must be in container for function to return true

Result

true if all elements are contained in given collection, false otherwise.

Examples


$array = [1, 2, 3, 4]
contains?($array, [1]) == true
contains?($array, [5]) == false
contains?($array, [2, 1, 3, 3]) == true
contains?($array, [1, 2, 3, 5]) == false
@servers = rs.deployments.get(filter: "name==default").servers()
@server = rs.get(href: "servers/123") # Assume this server belongs to a deployment named 'default'
contains?(@servers, @server) == true

empty?($array or @collection)

Returns true if the given collection (resource collection or array of values) is empty, false otherwise.

Arguments

Position Possible Values Required Default Value
1

resource collection -or- 
array of values

 yes none

Result

true if given collection is empty, false otherwise.

any?($array[, $value_or_regexp])

This function checks for the existence of an element in an array of JSON values. When only an array is given then returns true if the array contains a value that is neither null nor false. When both an array and a value are provided then returns true if the array contains at least once the given value. If the value is a regular expression, it will return true if there is a least one value that is a string and that matches the regexp. The syntax used to write a regular expressions is "/regexp/".

Arguments

Position Possible Values Required Default Value
1

array of values

 yes none
2

value or regular expression

 no none

Result

true or false.

Examples


$array_of_false = [false, false, null]
any?($array_of_false) == false # All elements are null or false, result is false
$array = [1, 2, 3, "a", "b", "cde"]
any?($array) == true # Array contains values that are not either false or null, result is true
any?($array, 1) == true # Array contains the value 1
any?($array, "cd") == false # Array does not contain value "cd"
any?($array, "/cd/") == true # Value "cde" matches regular expression "cd"

all?($array[, $value_or_regexp])

This function checks whether all elements of an array have a given value. When only an array is provided, then it returns true if the array does not contain a value that is either null or false. When both an array and a value is provided, then it returns true if the array values all match the given value. If the value is a regular expression, it will return true if all the values in the array are all strings that match the regular expression.

Arguments

Position Possible Values Required Default Value
1

array of values

 yes none
2

value or regular expression

 no none

Result

true or false.

Examples


$array_with_one_false = [1, 2, false]
all?($array_with_one_false) == false # One element is null or false, result is false
$array = [1, 2, 3, "a", "b", "cde"]
all?($array) == true # Array contains no null or false, result is true
all?($array, 1) == false # Not all values are one
all?($array, "/cd/") == false # Not all values are strings that match regular expression "cd"

select($array or @collection, $hash)

This function extracts the elements of a resource collection or of an array of hashes that have fields or values with a given value. The name of the field or hash key that should be selected for comparison correspond to the keys of the hash given as second argument. The values of that hash are the values that the resource fields or hash entries must be selected. If the resource field or hash values are strings, then the selector hash value can represent regular expressions.

Arguments

Position Possible Values Required Default Value Comment
1

resource collection
-or- 
array of values

 yes none

Container being tested
2

hash

yes

none

Resource field names associated with value that should be filtered on -or- 
Hash key name associated with value that should be filtered on

Result

A resource collection composed of resources that have fields with the given values or an array of hashes that have the given values for given keys.

Examples


@servers = rs.deployments.get(filter: "name==default").servers()
@app_servers = select(@servers, { "name": "/app/" }) # @app_servers contains servers whose name match
                                                     # the regular expression "app" (i.e. contain the string "app")
$hashes = [{ "key": "value1" }, { "key": "value2" }]
$hashes_with_value1 = select($hashes, { "key": "value1" }) # $hashes_with_value1 contains hashes whose values
                                                           # stored in key "key" is "value1"

unique($array or @collection)

This function traverses the given collection and returns a new collection made of all the unique elements. Two resources are considered identical if they have the same href.

Arguments

Position Possible Values Required Default Value Comment
1

resource collection
-or- 
array of values

 yes none

Container to be traversed and whose unique elements should be extracted

Result

A collection composed of the distinct elements in the initial collection. The types of the elements is preserved (so the result is a resource collection or an array of values depending on the argument).

Examples


@servers = rs.deployments.get(filter: "name==default").servers()
@duplicated_servers = @servers + @servers
@unique_servers = unique(@duplicated_servers)
assert @servers == @unique_servers

Resource Management

The following functions help you to work with cloud resources. They are helper functions that encapsulate logic to help create and delete resources in a pre-defined way, saving you from having to implement the logic in your code.

provision(@declaration)

This function provisions the resource passed in as a resource declaration. A resource declaration is a description of what a resource ought to be and consists of a hash which defines the resource namespace, type and fields which characterize the resource.

The general behavior is that this function creates the resource and waits until it is in a usable state -- what exactly that means for each resource is a bit different. The following table lists the behavior of the provision function for each RightScale resource.

Resource Behavior Failure Behavior
Server

Create the Server

Launch the Server

Wait for the Server to become "operational"

Terminate the Server

Wait for the Server to terminate

Delete the Server
ServerArray

Create the ServerArray

Enable the ServerArray

Launch the ServerArray

Wait for at least the "min_count" number of instances to become "operational"

Terminate all instances in the ServerArray

Wait for all instances to terminate

Delete the ServerArray
Instance

Create the Instance

Launch the Instance

Wait for the Instance to become "running"

Terminate the Instance

Wait for the Instance to terminate

Delete the Instance
IPAddress Create the IPAddress N/A
IPAddressBinding Create the IPAddressBinding N/A
Volume

Create the Volume

Wait for the volume to become "available"

 Delete the Volume
VolumeSnapshot Create the VolumeSnapshot N/A
VolumeAttachment Create the VolumeAttachment N/A

delete(@resource)

This function cleans up and deletes the specified resource. Generally speaking, this function will take care to trigger the resource to be decommissioned and then remove the resource altogether -- the specific actions for each resource are a bit different. The following table lists the behavior of the delete function for each RightScale resource.

Resource Behavior
Server Terminate the Server

Wait for the Server to terminate

Delete the Server resource
ServerArray

Disable the ServerArray

Terminate all instances in the ServerArray

Wait for all instances to terminate

Delete the ServerArray
Instance

Terminate the Instance

Wait for the Instance to terminate

Delete the Instance
IPAddress Delete the IPAddress
IPAddressBinding Delete the IPAddressBinding
Volume

Delete the Volume
VolumeSnapshot Delete the VolumeSnapshot
VolumeAttachment Delete the VolumeAttachment

Boolean Logic

The following set of functions all evaluate to true or false. They provide an alternate notation to using operators that may lend itself better when writing declarative code (e.g. when defining the fields of a declaration).

equals?($left or @left, $right or @right)

This function checks whether both arguments are equals, it is equivalent to doing left == right.

Arguments

Position Possible Values Required Default Value
1

resource collection
-or- 
value

 yes none
2

resource collection
-or- 
value

 yes none

Result

true or false.

Examples


$a = 1
$b = 2
$c = 1
equals?($a, $b) == false
equals?($a, $c) == true

logic_and($left, $right) and logic_or($left, $right)

These functions apply the logical and or logical or operators respectively to their arguments. They are equivalent o $left && $right and $left || $right respectively.

Arguments

Position Possible Values Required Default Value
1

value

 yes none
2

value

 yes none

Result

true or false.

Examples


$anything_but_null = "foobar"
logic_and($anything_but_null, false) == false
logic_and($anything_but_null, true) == true
logic_and($anything_but_null, null) == false
logic_and(null, null) == false

logic_or($anything_but_null, false) == true
logic_or($anything_but_null, true) == true
logic_or($anything_but_null, null) == true
logic_or(null, null) == false

logic_not($value​)

Applies the logical not operator.

Arguments

Position Possible Values Required Default Value
1

value

 yes none

Result

true or false.

Examples


logic_not(true) == false
logic_not(false) == true
$any_value_but_null = "foobar"
logic_not($any_value_but_null) == false
logic_not(null) == true

Data Conversion

The following set of functions are used to convert values from one type to another.

to_s($value)

Convert value to string. The semantic for each type is summarized in the following table:

 

Type Result Example

string

no change

to_s("foo") == "foo"

number

string representation of number

to_s(1) == "1"

boolan

string representation of boolean

to_s(true) == "true"

datetime

string representation of datetime

to_s(d"1/1/2012 6:59") == "1/1/2012 6:59"

null

string "null"

to_s(null) == "null"

array

JSON representation of array

to_s([1, 2, "3"]) == "[1,2,\"3\"]"
hash JSON representation of an hash to_s({ "one": 1, "two": 2, "three": 3 }) == "{\"one\": 1, \"two\": 2, \"three\": 3}"

to_n($value)

Convert a value to a number. The only types that can be converted to numbers are strings, booleans, and datetimes. Attempting to convert a value of a different type (e.g. an array) will result in an error.

 

Type Result Example

string

corresponding number or 0 if string does not represent a number

to_n("1.23123") == 1.23123; to_n("foo") == 0

number

no change

to_n(1) == 1

boolan

1 for true, 0 for false

to_n(true) == 1

datetime

number of seconds since the epoch

to_n(d"1/26/2012 1:49:35") == 1327542575

null

0

to_n(null) == 0

to_b($value)

Convert value to boolean. The only types that can be converted to booleans are strings and numbers. Attempting to convert a value of a different type (e.g. an array) will result in an error.

 

Type Result Example

string

true if string is "true", false otherwise

to_b("true") == true; to_b("foo") == false

number

true if non 0, false otherwise

to_b(42) == true; to_b(0) == false

boolean

no change

to_b(true) == true

to_d($value)

Convert value to datetime. The only types that can be converted to datetimes are strings and numbers. Attempting to convert a value of a different type (e.g. an array) will result in an error. The accepted syntax for strings representing datetime is:


year/month/day [h:m[:s]] [AM|PM]

Trying to coerce a string that does not match this syntax to a datetime value results in an error.

 

Type Result Example

string

Corresponding datetime if syntax is correct, error otherwise

to_d("1/1/2012") == d"1/1/2012"

number

datetime with corresponding unix timestamp

to_d(42) == d"1/1/1970 00:00:42"

datetime

no change

  

to_a($value)

Convert hash to array of pairs. Converting a value that is not a hash will result in an error.

 

Type Result Example

hash

Corresponding array of pairs, ordering is random

to_a({ "one": 1, "two": 2, "three": 3 }) == [ ["two", 2], ["one", 1], ["three", 3] ]

to_object(@declaration or @collection) 

Convert given resource declaration or resource collection into a JSON object. Especially useful to convert a declaration into an object, manipulate that object and assign it back to a declaration so that e.g. provision() may be called on it.

 

Type Result Example

collection
-or-
declaration

 

JSON object containing declaration or collection fields. Note that objects created from declarations may be assigned back to a reference.

$data = to_object(@servers)

 

to_json($value)

Convert a value into a JSON string.

 

Type Result Example

any

RCL value

to_json({ "one": 1, "two": 2, "three": 3 }) == '{"one":1,"two":2,"three":3}'

from_json($value)

Convert a string value into a RCL value.

Type Result Example

string

JSON string

from_json('{"one":1,"two":2,"three":3}') == { "one": 1, "two": 2, "three": 3 }

Process Information

self()

This function returns a resource collection made of a single resource: the running process.

Arguments

None

Result

A resource collection consisting of a single element: the current process.

task_name()

Returns the global name of the current task. See Cloud Workflow Processes for information on tasks.

Arguments

None.

Result

A string that represents the global name of the current task.

Examples


concurrent do
  sub task_name: launch_app do
    $servers = rs.tags.by_tag(resource_type: "servers", tags: ["app:name=foo" ])
    $arrays = rs.tags.by_tag(resource_type: "server_arrays", tags: [ "app:name=foo" ])
    concurrent do
    ​  sub task_name: launch_servers do
       ​ $servers.launch()
        $name = task_name() # $name == launch_app/launch_servers
      end
      sub task_name: launch_arrays do
        $arrays.launch()
        $name = task_name() # $name == launch_app/launch_arrays
      end
    end
  end
  sub task_name: notify do
    # ... do things
  end
end

tasks()

Arguments

None.

Result

Returns a hash of task status keyed by global task name. Valid values for a task status are: completed, aborted, canceled, paused, or running.

task_status($task_name)

Returns the status of the given task. The task name can be relative or absolute (relative match is tried first then absolute if there is no task with a relative name matching the argument).

Arguments

Position Possible Values Required Default Value Comment
1

strings

 yes none

Name of task whose status should be returned

Result

completed, aborted, canceled, paused or running. Returns null for non-existent tasks.

Data Introspection

type(object)

Returns the name of the type of the given argument. This function is mainly meant to help developing and debugging processes. If the object is a value then the possible type names are: string, number, boolean, datetime, null, array or hash. If the object is a resource collection then the returned name consist of <namespace>.<resource type>. If the object is a declaration, then function will return declaration.

Arguments

Position Possible Values Required Default Values Comment
1

resource collection

value

declaration

yes

 none

Object for which type should be retrieved

Result

A string representation of the object type.

Examples


@servers = rs.deployments.get(filter: "name==default").servers()
$type_name = type(@servers) # rs.servers

inspect(object)

The inspect() function returns a human readable representation of the object given as argument. This function is meant as a debugging aid.

Arguments

Position Possible Values Required Default Value
1

resource collection

value

 yes none

Result

String representation of the given object.

Examples


@servers = rs.deployments.get(filter: "name==default").servers()
log_info(inspect(@servers))

 

String Manipulation

split($string, $separator_or_regexp)

Split given string around matches of the given separator or regular expression.

Arguments

Position Possible Values Required Default Value Comment
1

String value

 yes none  
2

String value

 yes none

May represent a regular expression

Result

Array of strings.

Examples


$text = "some-dash-delimited--string--"
$values = split($text, "/-+/") # ["some", "dash", "delimited", "string"]

join($array[, $separator])

Join elements of array into a single string using given separator if any.

Arguments

Position Possible Values Required Default Value Comment
1 string value yes none  
2 string value no --

Empty string by default

Result

String.

Examples


$values = ["some", "dash", "delimited", "string"]
join($values, "-") == "some-dash-delimited-string"
join($values) == "somedashdelimitedstring"
 

HTTP/HTTPS Functions

This set of functions provides the ability to call HTTP/HTTPS endpoints from within Cloud Workflow. There is one function for each of the well-known HTTP verbs (get, post, head, put, patch, delete, options, and trace). The functions take all request attributes as parameters and return the response in a hash value with the keys "code", "headers", "cookies", and "body" (each containing their respective response attributes).

There is also a generic function called http_request which takes the verb as a parameter for any type of HTTP/HTTPS call.

General Information

Making Requests

When using these functions, there is some specific behavior that is of interest:

  • If a body is given for the request and the corresponding value is not a string then the functions will encode the value in JSON.
  • The verb-specific functions take a single `url` argument that includes the scheme, host, href, and query strings.
  • The generic http_request function takes individual arguments (host, https, href, query_strings) to form the url.
Common Parameters for HTTP/S functions

The following parameters are available for all verb-specific and generic HTTP functions.

 

Name Possible Values Required Description Example Default
headers hash of string -> string values no HTTP request headers, the keys are the classical "content-type" (or "content_type"), "accepts", etc. Passing lowercase with underscore instead of dash is OK, the implementation normalizes to standard HTTP header names behind the scenes.

{ "X-Api-Version": "1.0" }

  
body string (or any value if content-type is JSON) no The request body. When unspecified and the method is one of those that expect a body, will default to "" (empty string). A body can be given for methods that don't require it (GET, HEAD) and it will probably get discarded by the server.    
raw_response boolean no The default is false. When false (default) and the response is "application/json" (or an extension of it), the response body will contain the parsed value (not the JSON string). 

In case of XML content (and unless "raw_response" is set to true), the XML is turned into a JSON-compatible data structure (a representation of the XML tree).		 true false
basic_auth an object with keys "username" and "password" no

Specifies a pair (username, password) for the basic authentication of this request.
{ "username": "foo",
  "password": "bar" }
 
cookies Array of cookie objects no An array of cookies to send to the server. Only "name" and "value" are allowed.
[
  { "name": "zz",
    "value": "yy"
  }
]
 
noredirect boolean no The default is false. By default the http method will follow any redirection. Infinite loops are detected and raise an error. true false
insecure boolean no

The default is false. By default the http method will verify SSL certificates. When set to true, the check is not done.

 true false
signature an object with keys "type", "access_key", and "secret_key" no Used for signing requests for AWS. The type should be "aws". The "access_key" and "secret_key" fields specify the AWS credentials to use for signing the request. If the "access_key" or "secret_key" fields are not provided, the default AWS credentials (AWS_ACCESS_KEY_ID or AWS_SECRET_ACCESS_KEY) will be used. 
{ "type": "aws",
  "access_key": "myaccesskey",
  "secret_key": "mysecretkey" }
 
HTTP/S Function Responses

The return value of every HTTP/S function is a hash with the following elements:

 

Name Type Description Example
code number The response code. Eg: 200 200
headers hash The headers from the http response
{ "Connection": "keep-alive",
  "Content-Encoding": "gzip" }
cookies array of objects. The cookies received in the response

For a cookie received as string, "zz=yy; Domain=.foo.com; path=/; secure", it will be parsed as follows

[
  { "name": "zz",
    "value": "yy",
    "path": "/",
    "domain": ".foo.com",
    "expires": <DateTime formatted value>,
    "secure": true
  }
]
body

string if raw_response was set to true (or it was set to false but could not be parsed as an object)

object if raw_response was set to false (which is by default) and the content type was xml or json

 The body of the response  

http_get($params), http_post($params), http_head($params), http_put($params), http_patch($params), http_delete($params), http_options($params), http_trace($params)

The verb-specific functions have the following parameters, in addition to the "Common Parameters" listed above. The return value from these functions is documented above in "HTTP Function Responses".

 

Name Possible Values Required Description Example Default
url string yes The url for the request including the scheme (http/https), host, href, as well as query strings. "https://www.googleapis.com/drive/v2/...iewedDate=true"  

http_request($params)

The general function has the following parameters, in addition to the "Common Parameters" listed above. The return value from these functions is documented above in "HTTP Function Responses".

 

Name Possible Values Required Description Example Default
verb string yes The HTTP verb (should be one of get, post, patch, put, delete, options, head) "get"  
host string yes The host of the external service "www.googleapis.com"  
https boolean no Whether to https/http true false
href string no The href of the target resource relative to the host. "/drive/v2/files/123" ""
query_strings hash no

Query-string values (what comes after a "?" in the URL). Keys must be strings. Values are turned into strings (arrays and hashes are JSON encoded). All the values are escaped.

 { "updateViewedDate": true } {}

Miscellaneous

now()

Returns the current time in a datetime value.

Arguments

None.

Result

Date time value that represents the current time in UTC.

uuid()

Returns a string containing a Universally Unique IDentifier.

Arguments

None.

Result

A string containing a UUID.

sleep($duration)

Makes the current task sleep for the time expressed in seconds.

Arguments

Position Possible Values Required Default Value Examples
1 duration yes none

sleep(60) # sleep one minute

Result

None.

sleep_until(expression)

This function takes an expression that resolves to a value as argument. If the expression does not resolve to a value, then an error is raised. Sleeps until the expression evaluates to a value that is neither null nor false.

Arguments

Position Possible Values Required Default Value Comment
1 expression yes none

The expression that should return a value that is neither null nor false for the wait to stop

Result

None.

sleep_while(expression)

This function takes an expression that resolves to a value as argument. If the expression does not resolve to a value then an error is raised. Sleeps while the expression evaluates to a value that is neither null norfalse.

Arguments

Position Possible Values Required Default Value Comment
1 expression yes none

the expression that is run

Result

None.

keys($hash)

Return an array made of all the keys of the provided hash.

Arguments

Position Possible Values Required Default Value Comment
1 hash yes none

Hash for which keys should be retrieved

Result

Array of strings representing all the keys of the provided hash.

values($hash)

Return an array made of all the values of the provided hash.

Arguments

Position Possible Values Required Default Value Comment
1 hash yes none

Hash for which values should be retrieved

Result

Array of strings representing all the values of the provided hash.

map($mapping_name, $key_name, $value_name)

Return the value of a two level hash given a key and value name. This function is syntactic sugar around the [] operator. It may provide a better notation when writing declarative code e.g. in resource declarations. So doing map($hash, $key, $value) is equivalent to $hash[$key][$value].

 

Arguments

Position Possible Values Required Default Value Comment
1 hash yes none

Hash for which value should be retrieved
2 string yes none Name of key
3 string yes none Name of value

Result

Hash value at given key and value name.

xpath($xml_string, $xpath)

Using a XPath string, extracts information out of an XML string.

Arguments

Position Possible Values Required Default Value Comment
1 string yes none

XML string
2 string yes none XPath string like "//item[2]/name/text()" or "css:div.li" path

The xpath argument can be passed a "css:" prefix, in which case the path is a CSS path, not a XPath.

 

Result

Array of [XML] strings.

RCL Resources Cloud Workflows & Definitions Variables Attributes & Error Handling Branching & Looping Processes ► Functions Operators Mapping
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09:56, 19 Mar 2015

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