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New State - ForEach (#143) 

* New State - ForEach

* updating documentation about foreach state

* foreach state - parallel execution
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Tihomir Surdilovic 2020-01-19 02:02:46 -05:00 committed by GitHub
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165
workflow/spec/schema/serverless-workflow-schema-01.json
View File

@ -94,6 +94,10 @@
{
"title": "Relay State",
"$ref": "#/definitions/relaystate"
},
{
"title": "ForEach State",
"$ref": "#/definitions/foreachstate"
}
]
}
@ -379,6 +383,10 @@
{
"title": "Relay State",
"$ref": "#/definitions/relaystate"
},
{
"title": "ForEach State",
"$ref": "#/definitions/foreachstate"
}
]
}
@ -428,9 +436,6 @@
"type": "string",
"description": "Amount of time (ISO 8601 format) to delay"
},
"loop": {
"$ref": "#/definitions/loop"
},
"onError": {
"type": "array",
"description": "OnError Definition",
@ -504,9 +509,6 @@
"$ref": "#/definitions/eventactions"
}
},
"loop": {
"$ref": "#/definitions/loop"
},
"onError": {
"type": "array",
"description": "States runtime error handling definitions",
@ -567,9 +569,6 @@
"$ref": "#/definitions/action"
}
},
"loop": {
"$ref": "#/definitions/loop"
},
"onError": {
"type": "array",
"description": "OnError Definition",
@ -644,9 +643,6 @@
"$ref": "#/definitions/branch"
}
},
"loop": {
"$ref": "#/definitions/loop"
},
"onError": {
"type": "array",
"description": "OnError Definition",
@ -711,9 +707,6 @@
"filter": {
"$ref": "#/definitions/filter"
},
"loop": {
"$ref": "#/definitions/loop"
},
"choices": {
"type": "array",
"description": "Defines an ordered set of Match Rules against the input data to this state",
@ -812,9 +805,6 @@
"filter": {
"$ref": "#/definitions/filter"
},
"loop": {
"$ref": "#/definitions/loop"
},
"onError": {
"type": "array",
"description": "OnError Definition",
@ -898,6 +888,120 @@
"required": ["name", "type", "transition"]
}
},
"foreachstate": {
"type": "object",
"description": "Execute a set of defined states for each element of the data input array",
"properties": {
"id": {
"type": "string",
"description": "Unique State id",
"minLength": 1
},
"name": {
"type": "string",
"description": "State name"
},
"type": {
"type" : "string",
"enum": ["FOREACH"],
"description": "State type"
},
"end": {
"type": "boolean",
"default": false,
"description": "Is this state an end state"
},
"inputCollection": {
"type": "string",
"description": "JSONPath expression selecting an JSON array element of the states data input"
},
"outputCollection": {
"type": "string",
"description": "JSONPath expression specifying where in the states data output to place the final data output of each iteration of the executed states"
},
"inputParameter": {
"type": "object",
"description": "JSONPath expression specifying an JSON object field of the states data input. For each parallel iteration, this field will get populated with a unique element of the inputCollection array"
},
"max": {
"type": "integer",
"default": "0",
"minimum": 0,
"description": "Specifies how upper bound on how many iterations may run in parallel"
},
"timeDelay": {
"type": "string",
"description": "|Amount of time (ISO 8601 format) to wait between each iteration "
},
"startsAt": {
"type": "string",
"description": "Unique name of a states in the states array representing the starting state to be executed"
},
"states": {
"type": "array",
"description": "States to be executed for each of the elements of inputCollection",
"items": {
"type": "object",
"anyOf": [
{
"title": "Delay State",
"$ref": "#/definitions/delaystate"
},
{
"title": "Event State",
"$ref": "#/definitions/eventstate"
},
{
"title": "Operation State",
"$ref": "#/definitions/operationstate"
},
{
"title": "Switch State",
"$ref": "#/definitions/switchstate"
},
{
"title": "SubFlow State",
"$ref": "#/definitions/subflowstate"
},
{
"title": "Relay State",
"$ref": "#/definitions/relaystate"
},
{
"title": "ForEach State",
"$ref": "#/definitions/foreachstate"
}
]
}
},
"filter": {
"$ref": "#/definitions/filter"
},
"onError": {
"type": "array",
"description": "States error handling definitions",
"items": {
"type": "object",
"$ref": "#/definitions/error"
}
},
"transition": {
"description": "Next transition of the workflow after subflow has completed",
"$ref": "#/definitions/transition"
}
},
"if": {
"properties": {
"end": { "const": true }
}
},
"then": {
"required": ["name", "type", "inputCollection", "inputParameter", "startsAt", "states"]
},
"else": {
"required": ["name", "type", "transition", "inputCollection", "inputParameter", "startsAt", "states"]
}
},
"defaultchoice": {
"type": "object",
"description": "Default Choice",
@ -1024,31 +1128,6 @@
"required": [
"body"
]
},
"loop": {
"type": "object",
"description": "Defines state Looping Information",
"properties": {
"inputCollection": {
"type": "string",
"description": "Selects a collection of the states inputPath"
},
"outputCollection": {
"type": "string",
"description": "Selects a collection of the states outputPath"
},
"completionCondition": {
"type": "string",
"description": "Boolean expression (evaluated after each iteration) that controls the loop. If this expression is true looping stops even if not all collection elements are processesd."
},
"timeDelay": {
"type": "string",
"description": "Amount of time (ISO 8601 format) to wait between each loop"
}
},
"required": [
"inputCollection"
]
}
}
}

61
workflow/spec/spec-examples.md
View File

@ -4,7 +4,7 @@
- [Hello World](#Hello-World-Example)
- [Greeting](#Greeting-Example)
- [Solving Math Problems (Looping)](#Solving-Math-Problems-Example)
- [Solving Math Problems (ForEach)](#Solving-Math-Problems-Example)
- [Parallel Execution](#Parallel-Execution-Example)
- [Applicant Request Decision (Switch + SubFlow)](#Applicant-Request-Decision-Example)
- [Provision Orders (Error Handling)](#Provision-Orders-Example)
@ -149,7 +149,8 @@ output, which then becomes the data output of the workflow itself (as it is the
#### Description
In this example we show off looping in an Operation state. The state will loop over a collection of simple math expressions which are
In this example we show how to iterate over some data input using the ForEach state.
The state will iterate over a collection of simple math expressions which are
passed in as the workflow data input:
```json
@ -157,21 +158,12 @@ passed in as the workflow data input:
"expressions": ["2+2", "4-1", "10x3", "20/2"]
}
```
The ForEach state will execute a single defined operation state for each math expression. The operation
state contains an action which calls a serverless function which actually solves the expression
and returns its result.
The operation state contains an action which calls the serverless function that solves the math expression and returns its answer.
The results of the action is assumed to be the answer, for example for the first expression:
```
"4"
```
The state filter is then used to only return the results of the solved math expressions which becomes the workflow data output:
```json
["4", "3", "30", "10"]
```
Results of all mathe expressions are accumulated into the data output of the ForEach state which become the final
result of the workflow execution.
#### Workflow JSON
@ -187,26 +179,33 @@ The state filter is then used to only return the results of the solved math expr
}
],
"states":[
{
{
"name":"Solve",
"type":"OPERATION",
"actionMode":"SEQUENTIAL",
"actions":[
"type":"FOREACH",
"inputCollection": "$.expressions",
"inputParameter": "$.singleexpression",
"outputCollection": "$.results",
"startsAt": "GetResults",
"states": [
{
"functionref": {
"refname": "solveMathExpressionFunction",
"parameters": {
"expression": "$."
}
}
"name":"GetResults",
"type":"OPERATION",
"actionMode":"SEQUENTIAL",
"actions":[
{
"functionref": {
"refname": "solveMathExpressionFunction",
"parameters": {
"expression": "$.singleexpression"
}
}
}
],
"end": true
}
],
"loop": {
"inputCollection": "$.expressions",
"outputCollection": "$.answers"
},
"filter": {
"outputPath": "$.answers"
"outputPath": "$.results"
},
"end": true
}

576
workflow/spec/spec.md
View File

@ -192,13 +192,38 @@ Here we define details of the Serverless Workflow definitions:
"items": {
"type": "object",
"anyOf": [
{ "$ref": "#definitions/delaystate" },
{ "$ref": "#definitions/eventstate" },
{ "$ref": "#definitions/operationstate" },
{ "$ref": "#definitions/parallelstate" },
{ "$ref": "#definitions/switchstate" },
{ "$ref": "#definitions/subflowstate" },
{ "$ref": "#definitions/relaystate" }
{
"title": "Delay State",
"$ref": "#/definitions/delaystate"
},
{
"title": "Event State",
"$ref": "#/definitions/eventstate"
},
{
"title": "Operation State",
"$ref": "#/definitions/operationstate"
},
{
"title": "Parallel State",
"$ref": "#/definitions/parallelstate"
},
{
"title": "Switch State",
"$ref": "#/definitions/switchstate"
},
{
"title": "SubFlow State",
"$ref": "#/definitions/subflowstate"
},
{
"title": "Relay State",
"$ref": "#/definitions/relaystate"
},
{
"title": "ForEach State",
"$ref": "#/definitions/foreachstate"
}
]
}
},
@ -412,7 +437,10 @@ States define building blocks of the Serverless Workflow. The specification defi
- **[SubFlow State](#SubFlow-State)**: Allows execution of a sub-workflow.
- **[Relay State](#Relay-State)**: Used to relay state's data input to output without executing any actions. State's data input can be filtered.
- **[ForEach State](#ForEach-State)**: Allows a set of defined states to be executed for each element of a data input array.
We will start defining each individual state:
### Event State
@ -425,7 +453,6 @@ We will start defining each individual state:
| end |Is this state an end state | boolean | no |
| [eventActions](#eventstate-eventactions) | Define what events trigger one or more actions to be performed | array | yes |
| [filter](#Filter-Definition) | State data filter | object | yes |
| [loop](#Loop-Definition) | State loop information | object | yes |
| [onError](#Workflow-Error-Handling) |States error handling definitions | array | no |
<details><summary><strong>Click to view JSON Schema</strong></summary>
@ -466,9 +493,6 @@ We will start defining each individual state:
"filter": {
"$ref": "#/definitions/filter"
},
"loop": {
"$ref": "#/definitions/loop"
},
"onError": {
"type": "array",
"description": "States error handling definitions",
@ -795,9 +819,6 @@ Defines a transition from point A to point B in the serverless workflow. For mor
},
"filter": {
"$ref": "#/definitions/filter"
},
"loop": {
"$ref": "#/definitions/loop"
},
"onError": {
"type": "array",
@ -836,14 +857,13 @@ Once all actions have been performed, a transition to another state can occur.
| Parameter | Description | Type | Required |
| --- | --- | --- | --- |
| id | Unique state id | string | no |
| name | State name | string | yes |
| type | State type | string | yes |
| end | Is this state an end start | boolean | no |
| [choices](#switch-state-choices) | Ordered set of matching rules to determine which state to trigger next | array | yes |
| [filter](#Filter-Definition) | State data filter | object | yes |
| [loop](#Loop-Definition) | State loop information | object | no |
| [onError](#Workflow-Error-Handling) | States error handling definitions | array | no |
| default | Next transition of the workflow if there is no match for any choices | object | yes (if end is set to false) |
| name |State name | string | yes |
| type |State type | string | yes |
| end |Is this state an end start | boolean | no |
| [choices](#switch-state-choices) |Ordered set of matching rules to determine which state to trigger next | array | yes |
| [filter](#Filter-Definition) |State data filter | object | yes |
| [onError](#Workflow-Error-Handling) |States error handling definitions | array | no |
| default |Next transition of the workflow if there is no match for any choices | object | yes (if end is set to false) |
<details><summary><strong>Click to view JSON Schema</strong></summary>
@ -886,9 +906,6 @@ Once all actions have been performed, a transition to another state can occur.
},
"filter": {
"$ref": "#/definitions/filter"
},
"loop": {
"$ref": "#/definitions/loop"
},
"onError": {
"type": "array",
@ -1115,14 +1132,13 @@ There are four types of choices defined:
| Parameter | Description | Type | Required |
| --- | --- | --- | --- |
| id | Unique state id | string | no |
| name | State name | string | yes |
| type | State type | string | yes |
| end | If this state an end state | boolean | no |
| timeDelay | Amount of time (ISO 8601 format) to delay when in this state. For example: "PT15M" (delay 15 minutes), or "P2DT3H4M" (delay 2 days, 3 hours and 4 minutes) | integer | yes |
| [filter](#Filter-Definition) | State data filter | object | yes |
| [loop](#Loop-Definition) | State loop information | object | no |
| [onError](#Error-Handling) | States error handling definitions | array | no |
| [transition](#Transitions) | Next transition of the workflow after the delay | string | yes (if end is set to false) |
| name |State name | string | yes |
| type |State type | string | yes |
| end |If this state an end state | boolean | no |
| timeDelay |Amount of time (ISO 8601 format) to delay when in this state. For example: "PT15M" (delay 15 minutes), or "P2DT3H4M" (delay 2 days, 3 hours and 4 minutes) | integer | yes |
| [filter](#Filter-Definition) |State data filter | object | yes |
| [onError](#Error-Handling) |States error handling definitions | array | no |
| [transition](#Transitions) |Next transition of the workflow after the delay | string | yes (if end is set to false) |
<details><summary><strong>Click to view JSON Schema</strong></summary>
@ -1157,9 +1173,6 @@ There are four types of choices defined:
"filter": {
"$ref": "#/definitions/filter"
},
"loop": {
"$ref": "#/definitions/loop"
},
"onError": {
"type": "array",
"description": "States error handling definitions",
@ -1196,14 +1209,13 @@ Delay state waits for a certain amount of time before transitioning to a next st
| Parameter | Description | Type | Required |
| --- | --- | --- | --- |
| id | Unique state id | string | no |
| name | State name | string | yes |
| type | State type | string | yes |
| end | If this state and end state | boolean | no |
| [branches](#parallel-state-branch) | List of branches for this parallel state| array | yes |
| [filter](#Filter-Definition) | State data filter | object | yes |
| [loop](#Loop-Definition) | State loop behavior | object | no |
| [onError](#Error-Handling) | States error handling definitions | array | no |
| [transition](#Transitions) | Next transition of the workflow after all branches have completed execution | string | yes (if end is set to false) |
| name |State name | string | yes |
| type |State type | string | yes |
| end |If this state and end state | boolean | no |
| [branches](#parallel-state-branch) |List of branches for this parallel state| array | yes |
| [filter](#Filter-Definition) |State data filter | object | yes |
| [onError](#Error-Handling) |States error handling definitions | array | no |
| [transition](#Transitions) |Next transition of the workflow after all branches have completed execution | string | yes (if end is set to false) |
<details><summary><strong>Click to view JSON Schema</strong></summary>
@ -1242,9 +1254,6 @@ Delay state waits for a certain amount of time before transitioning to a next st
"filter": {
"$ref": "#/definitions/filter"
},
"loop": {
"$ref": "#/definitions/loop"
},
"onError": {
"type": "array",
"description": "States error handling definitions",
@ -1308,13 +1317,34 @@ Branches contain one or more states. Each branch must define a starting state vi
"items": {
"type": "object",
"anyOf": [
{ "$ref": "#definitions/delaystate" },
{ "$ref": "#definitions/eventstate" },
{ "$ref": "#definitions/operationstate" },
{ "$ref": "#definitions/parallelstate" },
{ "$ref": "#definitions/switchstate" },
{ "$ref": "#definitions/subflowstate" },
{ "$ref": "#definitions/relaystate" }
{
"title": "Delay State",
"$ref": "#/definitions/delaystate"
},
{
"title": "Event State",
"$ref": "#/definitions/eventstate"
},
{
"title": "Operation State",
"$ref": "#/definitions/operationstate"
},
{
"title": "Switch State",
"$ref": "#/definitions/switchstate"
},
{
"title": "SubFlow State",
"$ref": "#/definitions/subflowstate"
},
{
"title": "Relay State",
"$ref": "#/definitions/relaystate"
},
{
"title": "ForEach State",
"$ref": "#/definitions/foreachstate"
}
]
}
},
@ -1345,15 +1375,14 @@ Parallel state must wait for all branches which have this property set to "true"
| Parameter | Description | Type | Required |
| --- | --- | --- | --- |
| id | Unique state id | string | no |
| name | State name | string | yes |
| type | State type | string | yes |
| end | If this state and end state | boolean | no |
| waitForCompletion | If workflow execution must wait for sub-workflow to finish before continuing | boolean | yes |
| workflowId | Sub-workflow unique id | boolean | no |
| [filter](#Filter-Definition) | State data filter | object | yes |
| [loop](#Loop-Definition) | State loop information | object | no |
| [onError](#State-Exception-Handling) | States error handling definitions | array | no |
| [transition](#Transitions) | Next transition of the workflow after subflow has completed | string | yes (if end is set to false) |
| name |State name | string | yes |
| type |State type | string | yes |
| end |If this state and end state | boolean | no |
| waitForCompletion |If workflow execution must wait for sub-workflow to finish before continuing | boolean | yes |
| workflowId |Sub-workflow unique id | boolean | no |
| [filter](#Filter-Definition) |State data filter | object | yes |
| [onError](#State-Exception-Handling) |States error handling definitions | array | no |
| [transition](#Transitions) |Next transition of the workflow after subflow has completed | string | yes (if end is set to false) |
<details><summary><strong>Click to view JSON Schema</strong></summary>
@ -1393,9 +1422,6 @@ Parallel state must wait for all branches which have this property set to "true"
"filter": {
"$ref": "#/definitions/filter"
},
"loop": {
"$ref": "#/definitions/loop"
},
"onError": {
"type": "array",
"description": "States error handling definitions",
@ -1603,14 +1629,306 @@ $.people[?(@.age >= 40)]
to test if your workflow behaves properly for the case when there are people who's age is greater or equal 40.
### ForEach State
| Parameter | Description | Type | Required |
| --- | --- | --- | --- |
| id | Unique state id | string | no |
| name | State name | string | yes |
| type | State type | string | yes |
| end |Is this state an end state | boolean | no |
| inputCollection | JSONPath expression selecting an JSON array element of the states data input | string | yes |
| outputCollection | JSONPath expression specifying where in the states data output to place the final data output of each iteration of the executed states | string | no |
| inputParameter | JSONPath expression specifying an JSON object field of the states data input. For each parallel iteration, this field will get populated with an unique element of the inputCollection array. | string | yes |
| max | Specifies how upper bound on how many iterations may run in parallel | integer | no |
| timeDelay | Amount of time (ISO 8601 format) to wait between each iteration | string | no |
| startsAt | Unique name of a states in the states array representing the starting state to be executed | string |yes |
| [states](#State-Definition) | States to be executed for each of the elements of inputCollection | array | yes |
| [filter](#Filter-Definition) | State data filter | object | no |
| [onError](#Error-Handling) | States error handling definitions | array | no |
| [transition](#Transitions) | Next transition of the workflow after state has completed | string | yes (if end is set to false) |
<details><summary><strong>Click to view JSON Schema</strong></summary>
```json
{
"type": "object",
"description": "Execute a set of defined states for each element of the data input array",
"properties": {
"id": {
"type": "string",
"description": "Unique State id",
"minLength": 1
},
"name": {
"type": "string",
"description": "State name"
},
"type": {
"type" : "string",
"enum": ["FOREACH"],
"description": "State type"
},
"end": {
"type": "boolean",
"default": false,
"description": "Is this state an end state"
},
"inputCollection": {
"type": "string",
"description": "JSONPath expression selecting an JSON array element of the states data input"
},
"outputCollection": {
"type": "string",
"description": "JSONPath expression specifying where in the states data output to place the final data output of each iteration of the executed states"
},
"inputParameter": {
"type": "object",
"description": "JSONPath expression specifying an JSON object field of the states data input. For each parallel iteration, this field will get populated with a unique element of the inputCollection array"
},
"max": {
"type": "integer",
"default": 0,
"minimum": 0,
"description": "Specifies how upper bound on how many iterations may run in parallel"
},
"timeDelay": {
"type": "string",
"description": "|Amount of time (ISO 8601 format) to wait between each iteration "
},
"startsAt": {
"type": "string",
"description": "Unique name of a states in the states array representing the starting state to be executed"
},
"states": {
"type": "array",
"description": "States to be executed for each of the elements of inputCollection",
"items": {
"type": "object",
"anyOf": [
{
"title": "Delay State",
"$ref": "#/definitions/delaystate"
},
{
"title": "Event State",
"$ref": "#/definitions/eventstate"
},
{
"title": "Operation State",
"$ref": "#/definitions/operationstate"
},
{
"title": "Switch State",
"$ref": "#/definitions/switchstate"
},
{
"title": "SubFlow State",
"$ref": "#/definitions/subflowstate"
},
{
"title": "Relay State",
"$ref": "#/definitions/relaystate"
},
{
"title": "ForEach State",
"$ref": "#/definitions/foreachstate"
}
]
}
},
"filter": {
"$ref": "#/definitions/filter"
},
"onError": {
"type": "array",
"description": "States error handling definitions",
"items": {
"type": "object",
"$ref": "#/definitions/error"
}
},
"transition": {
"description": "Next transition of the workflow after subflow has completed",
"$ref": "#/definitions/transition"
}
},
"if": {
"properties": {
"end": { "const": true }
}
},
"then": {
"required": ["name", "type", "inputCollection", "inputParameter", "startsAt", "states"]
},
"else": {
"required": ["name", "type", "transition", "inputCollection", "inputParameter", "startsAt", "states"]
}
}
```
</details>
The ForEach state can be used to execute a defined set of states for each element of an array (defined in the states data input).
While the [Parallel state](#Parallel-State) performs multiple branches of states using the
same data input, the ForEach state performs the defined steps for multiple entries of an array in the states data input.
Note that each iteration of the ForEach state should be executed in parallel.
You can use the "max" property to set the upper bound on how many iterations may run in parallel. The default
of the "max" property is zero, which places no limit on number of parallel executions.
States defined in the "states" property of the ForEach state can only transition to each other and
cannot transition to states outside of this state.
Similarly other workflow states cannot transition to one of the states defined within the ForEach state.
States defined in the "states" property must contain at least one state which is an end state (has the end property set to true).
Let's take a look at a simple ForEach state example through which we can explain this state:
In this example the data input to our ForEach state is an array of orders:
```json
{
"orders": [
{
"orderNumber": "1234",
"completed": true,
"email": "firstBuyer@buyer.com"
},
{
"orderNumber": "5678",
"completed": true,
"email": "secondBuyer@buyer.com"
},
{
"orderNumber": "9910",
"completed": false,
"email": "thirdBuyer@buyer.com"
}
]
}
```
and the state is defined as:
```json
{
"functions": [
{
"name": "sendConfirmationFunction",
"resource": "functionResourse"
}
],
"states": [
{
"name":"SendConfirmationForEachCompletedhOrder",
"type":"FOREACH",
"inputCollection": "$.orders[?(@.completed == true)]",
"inputParameter": "$.completedorder",
"startsAt": "SendConfirmation",
"states": [
{
"name":"SendConfirmation",
"type":"OPERATION",
"actionMode":"SEQUENTIAL",
"actions":[
{
"functionref": {
"refname": "sendConfirmationFunction",
"parameters": {
"orderNumber": "$.completedorder.orderNumber",
"email": "$.completedorder.email"
}
}
}
],
"end": true
}
],
"end": true
}
]
}
```
This ForEach state will first look at its inputCollection path to determine which array in the states data input
to iterate over.
In this case it will be "orders" array which contains orders information. The states inputCollection property
then further filters this array, only selecting elements of the orders array which have the completed property
set to true.
For each of the completed order the state will then execute the defined set of states in parallel.
For this example, the data inputs of staring states for the two itererations would be:
```json
{
"orders": [
{
"orderNumber": "1234",
"completed": true,
"email": "firstBuyer@buyer.com"
},
{
"orderNumber": "5678",
"completed": true,
"email": "secondBuyer@buyer.com"
},
{
"orderNumber": "9910",
"completed": false,
"email": "thirdBuyer@buyer.com"
}
],
"completedorder": {
"orderNumber": "1234",
"completed": true,
"email": "firstBuyer@buyer.com"
}
}
```
and:
```json
{
"orders": [
{
"orderNumber": "1234",
"completed": true,
"email": "firstBuyer@buyer.com"
},
{
"orderNumber": "5678",
"completed": true,
"email": "secondBuyer@buyer.com"
},
{
"orderNumber": "9910",
"completed": false,
"email": "thirdBuyer@buyer.com"
}
],
"completedorder": {
"orderNumber": "5678",
"completed": true,
"email": "secondBuyer@buyer.com"
}
}
```
Once iterations over the completed orders complete, workflow execution finishes as our ForEach state is an end state (has the end property set to true).
So in this example, our ForEach state will send two confirmation emails, one for each of the completed orders
defined in the orders array of its data input.
### Filter Definition
| Parameter | Description | Type | Required |
| --- | --- | --- | --- |
| inputPath | Input path (JSONPath) | string | yes |
| resultPath | Result Path (JSONPath) | string | no |
| outputPath | Output Path (JSONPath) | string | no |
| inputPath |Input path (JSONPath) | string | yes |
| resultPath |Result Path (JSONPath) | string | no |
| outputPath |Output Path (JSONPath) | string | no |
<details><summary><strong>Click to view JSON Schema</strong></summary>
@ -1637,121 +1955,7 @@ to test if your workflow behaves properly for the case when there are people who
</details>
Filters are used for managing workflow data flow.
This is described in detail in the [Information Passing](#Information-Passing) section.
### Loop Definition
| Parameter | Description | Type | Required |
| --- | --- | --- | --- |
| inputCollection | Selects a collection of the states inputPath | string | yes |
| outputCollection | Selects a collection of the states outputPath | string | no |
| completionCondition | Boolean expression (evaluated after each iteration) that controls the loop. If this expression is true looping stops even if not all collection elements are processesd | string | no |
| timeDelay | Amount of time (ISO 8601 format) to wait between each loop | string | no |
<details><summary><strong>Click to view JSON Schema</strong></summary>
```json
{
"type": "object",
"description": "Defines state Looping Information",
"properties": {
"inputCollection": {
"type": "string",
"description": "JSONPath, selects a collection of the states inputPath"
},
"outputCollection": {
"type": "string",
"description": "JSONPath, selects a collection of the states outputPath"
},
"completionCondition": {
"type": "string",
"description": "Boolean expression (evaluated after each iteration) that controls the loop. If this expression is true looping stops even if not all collection elements are processesd."
},
"timeDelay": {
"type": "string",
"description": "|Amount of time (ISO 8601 format) to wait between each loop "
}
},
"required": ["inputCollection"]
}
```
</details>
Loop definition allows states to be executed in a loop until a completion condition becomes true.
Looping happens over each element of the inputCollection parameter. This parameter must evaluate to a collection
of the states input data.
If the completionCondition expression is defined, this expression must be checked after each loop iteration.
If it evaluates to true, looping must stop even if looping over all elements of the inputCollection have not finished.
In addtion, the time delay property defines a wait period betwen each loop iteration.
If the state defines a result, the outputCollection parameter must resolve to a collection element of the states
output data. After each iteration the state data result is added to the collection evaluated by this expression.
Once looping has completed the state may transition to the next state defined, or end the workflow in case of an end state.
Here is an example of an Operation state which sends a confirmation email for each completed sales order
```json
{
"name": "Send order confirmation email",
"description": "Send email for each confirmed order",
"startsAt": "sendConfirmationEmail",
"functions": [
{
"name": "sendConfirmationEmailFunction",
"resource": "functionResourse"
}
],
"states":[
{
"name":"sendConfirmationEmail",
"type":"OPERATION",
"actionMode":"SEQUENTIAL",
"actions": [
{
"functionref": {
"refname": "sendConfirmationEmailFunction"
}
}
],
"end": true,
"loop": {
"inputCollection": "$.orders[?(@.completed == true)]"
}
}
]
}
```
The data input to the "sendConfirmationEmail" state could be for example:
```json
{
"orders": [
{
"orderNumber": "1234",
"completed": true,
"email": "firstBuyer@buyer.com"
},
{
"orderNumber": "5678",
"completed": true,
"email": "secondBuyer@buyer.com"
},
{
"orderNumber": "9910",
"completed": false,
"email": "thirdBuyer@buyer.com"
}
]
}
```
in which case this state will loop two times for each of the completed orders.
Filters are used for data flow through the workflow. This is described in detail in the [Information Passing](#Information-Passing) section.
### Transitions