Go Template Engine
Receiver SenderThis module implements the bpmn / template flow-service.
docker pull registry.goingrid.io/flow/gotmplengine:v0.1.0Table of Content
Properties
Controls
There are no Controls for the Template Engine.
However, you can access Controls from the Templates via the Functions provided for Controls:
- getRequestControl
- setRequestControl
- newControl
Protocol
The common Protocol used in ingrid can be accessed via the Templatefunctions. The Protocol is documented here Protocol
API
The flow service api lets you do the following:
- Implement Logic in the Templates. To Interact with all the other Services and Workers.
You have to pass a Template to the worker. The Worker will the run the Template against the Data he receives from a Channel and Execute the Commands from the Template
Service configuration
Like every other service, the log service includes all properties of the service configuration and since it listens on input the input configuration and also the output config.
In addition those are the following file service properties for the service:
| Parameter | Default value | Description |
|---|---|---|
| “Template” | "dispatcher.tmpl" |
“Template for File Import or Export” |
| “RequestTimeout” | 60s |
“Add a ‘filesum’ Attribute in the Document with the current File Filesum” |
| “StartTag” | "[[" |
“Template Start Tag” |
| “StopTag” | "]]" |
“Template Stop Tag” |
| “MultiThreading” | false | “Enable multi threading. Experimental (Not recommended/Not all Features will work as expected)” |
| “QueueManagement” | false | “Enable queue mangement. This need a dispatcher to be running” |
| “RegisterChannel” | "register" |
“Queue Manegement Register Channel” |
QueueManagement
If you intend to run Recursions with “Go Template Engine” you need to make sure, there are enought ‘workers’ running for the Job As all Workers are ‘blocking’ while running and the Hive does Round Robin Loadbalancing, there is a possibilitie of a deadlock. To prevent the system from deadlocks you should use “controlled entries” , “dispatcher” and a minimum of needed ‘flows’ for the Job.
For QueueManagement see the Service dispatcher
Template
The Template can be configured as
| Type | Notation |
|---|---|
| String | string://yourtemplate-content |
| Hive | hive://template-name.tmpl |
| File | file:///you/dir/template-name.bpmn |
The Template can either be an BPMN/XML Template containing a valid BPMN XML definition. See BPMN.
Or a simple golang Template.
Template functions
The following Template Functions are implemented.
Sprig has been added to. You can use all the Sprig Template functions
Example Template
The following code is the default dispatcher.
_debug Dispatch Request to Queue
[[- $queue := (printf "%s_%s" .Data.Class .Data.Operation) ]]
_debug [[- print " " $queue ]]
Request Class: [[ print .Data.Class ]] | Operation: [[ print .Data.Operation ]]
[[- $result := goodCall $queue .Data]]
Result Code: [[ print $result.Result.Code ]] | Message: [[ print $result.Result.Message]]
[[- $_ := setCurrentResult $result.Result ]]
A simple Echo Workflow would like this
[[ $name := getValue (getRequestData (getRequest)) "name" ]]
[[ $res := newResult ]]
[[ $res = setResultCode $res 200]]
[[ $res = setResultMsg $res ( print "Echo back from " $name) ]]
[[ $_ := setResult $res]]
Cheat Sheets
