OpenHAB
/
openhab-docs
mirror of https://github.com/openhab/openhab-docs.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
openhab-docs/configuration/blockly/index.md

297 lines
17 KiB
Markdown
Raw Permalink Blame History

This file contains ambiguous Unicode characters!

This file contains ambiguous Unicode characters that may be confused with others in your current locale. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to highlight these characters.

---
layout: documentation
title: Rules Blockly
---
<!-- markdownlint-disable MD036 -->
# Blockly Reference
One of the core feature that openHAB provides is writing rules to allow specific behaviour with the home automation system.
The usual way of developing rules is by coding them like described in the [Textual Rules](/docs/configuration/rules-dsl.html).
However, this art of programming may become intimidating early on and shy away away people with few or almost no experience in programming.
Therefore openHAB also provides a graphical way of writing rules which allows to put together rules in a rather visual way (even though some programming background may still help).
[[toc]]
## Introduction
The basic idea behind the visual paradigm and representation within openHAB is based on the [Google Blockly Support](https://developers.google.com/blockly) which has been integrated and which provides the basic blocks for programming like the ones on the left and the right side of the below images
_Blockly toolbox_
![blockly-toolbox-1](../images/blockly/blockly-toolbox-1.png)![blockly-toolbox-2](../images/blockly/blockly-toolbox-2.png)![blockly-toolbox-3](../images/blockly/blockly-toolbox-3.png)
All of these provide general functionality that is not specific to openHAB itself. If you want to learn more about how to use them, search for the many blockly tutorials that are available.
However, to leverage the full capabilities more than _50 specific blocks_ have been provided that are tailored for easy access of openHAB's capabilities.
This section provides a detailed description of the specific blocks and provides examples on how to use them. Note that some of the blocks (like voice, streaming or notifications) need some special setup within openHAB - in these case links to the respective documentation is provided.
Also see this ![youtube](../images/blockly/youtube-logo-small.png) [Intro](https://youtu.be/EdllUlJ7p6k?t=295) Quick Intro Blockly Rules
## Blockly is a code generator or how the 🦏 found the holy Grail
### Some history
Even though you may not notice it directly, the blocks are eventually used to automatically create code that can run on the openHAB server.
Please watch the ![youtube](../images/blockly/youtube-logo-small.png) video [Blockly as an ECMA-Script code generator](https://youtu.be/EdllUlJ7p6k?t=1739) for a live demo.
The code that is generated can be viewed when clicking the button ![showcode](../images/blockly/blockly-workspace-showcode-small.png) on the lower right corner of the blockly editor.
In general, the code that Blockly generates is JavaScript (aka ECMAScript) which exists in several flavours or versions.
The ECMAScript version that is used by Blockly in **openHAB 3** is **ECMAScript 5.1** and it is run by a component named **NashornJS** 🦏. [Nashorn JS](https://www.oracle.com/technical-resources/articles/java/jf14-nashorn.html) itself was part of Java until version 14 when it was dropped.
The generated rule code is run within the Java runtime (also known as JVM) on the openHAB server and as openHAB 4 has moved to Java 17, the old ECMAScript 5.1 is not directly available anymore within the JVM via Nashorn.
A replacement for the Nashorn JS is **GraalJS** ("the holy grail"), which is currently running **ECMAScript 2022** and therefore supports all modern JavaScript features, like arrow functions.
[**GraalJS**](https://github.com/oracle/graaljs) is already available in openHAB 3 when the [JS Scripting Addon](https://www.openhab.org/addons/automation/jsscripting/) is installed.
::: tip
Please convert your old rules as quickly as possible because only with GraalJS you can leverage the openHAB JavaScript library (aka _openhab-js_) in Blockly.
Using this library you can not only create much simpler code, it also allows **new functionality** that is not available with Nashorn.
**Note that some blocks are only available with the openhab-js library on GraalJS.**
:::
### openHAB 3 / openHAB 4 - Migration
#### Migrating Blockly rules to openHAB 4 is easy
From openHAB 4 on, the default script engine is GraalJS when Blockly creates new scripts.
From a technical perspective a rule internally holds a so-called MIME-type that tells openHAB how the generated JavaScript language has to be interpreted.
The (default) MIME-type `application/javascript` in openHAB 3 runs the rule with NashornJS, while this same MIME-type will run the Blocky rule with GraalJS in openHAB 4.
As a result when running a non-converted openHAB 3 Blocky rule on openHAB 4, openHAB 4 will run a rule that was meant for NashornJS with GraalJS, which will fail.
Therefore a conversion has to take place which in fact is not a lot of work:
There is the choice to
- convert each rule to GraalJS
- or keep the NashornJS Rules
but both need some work on each blockly rule you have.
#### Migration to GraalJS (recommended)
- Make sure the [JS Scripting Addon](https://www.openhab.org/addons/automation/jsscripting/) addon is installed.
- **To convert / migrate a rule that was created in openHAB 3 (NashornJS) to a GraalJS-compatible one for openHAB 4, simply open each Blockly rule once in openHAB 4 and save it - that's it.**
- In this case, nothing more needs to be installed additionally to openHAB 4.
#### Running openHAB 3 Blockly rules without migrating them right away
- If you still want to run the Blockly rules that were created in openHAB 3 for the time being without changing them (see above), you have to install the [JavaScript Scripting (Nashorn) Addon](https://www.openhab.org/addons/automation/jsscriptingnashorn/) which provides backwards compatibility until you have converted all rules.
- Open each Blockly rule or go to the Code TAB or Search for type: application/javascript;
- Replace it by `application/javascript;version=ECMAScript-5.1`.
Open the Blockly rule, find the following symbol and click on it.
![javascript-dialog](../images/blockly/blockly-javascript-dialog.png)
to choose the old version of JavaScript and then save the rule.
![choose-javascript](../images/blockly/blocky-choose-javascript.png)
- After the installation of the Addon both old rules created in openHAB 3 and new rules created in openHAB 4 can run on openHAB 4 at the same time.
- After all scripts of the rules have been converted, like explained above, please uninstall the JavaScript Scripting (Nashorn) addon to save memory.
- Note that this allows you to mix rules that run with NashornJS and some that run with GraalJS (see above).
## Looking for help
A special mention should go towards the **Help** entry in a block context menu [right click on any block](rules-blockly-before-using.html#block-context-menu) that links to a resource that is usually very helpful to understand the context of that particular block.
To retrieve the particular help for a block right click on a block to open the context menu and click on the **help**-entry:
![context-help](../images/blockly/blockly-context-help.png)
There is also a help-button available in each section that links to the documentation of the whole section.
![main-help-button](../images/blockly/blockly-main-help.png)
Please read this information first before asking questions in the forum. _In case you ask for help please always post the respective code that is being generated._
Also there is a good intro about that topic can be viewed at ![youtube](../images/blockly/youtube-logo-small.png) [Various Help Documentation available in openHAB Blocky](https://youtu.be/EdllUlJ7p6k?t=1589)
## Before using blockly
Please visit [Getting started with openHAB Blocklies and creating a rule](rules-blockly-before-using.html) before asking questions in the forum.
## Blockly Youtube Tutorials
Three Youtube tutorials have been made available via the [openHAB Youtube channel](https://www.youtube.com/c/OpenhabOrg):
- [Episode 1](https://www.youtube.com/watch?v=EdllUlJ7p6k)
- [Introduction](https://www.youtube.com/watch?v=EdllUlJ7p6k)
- [Quick Intro Blockly Rules](https://youtu.be/EdllUlJ7p6k?t=295)
- [Debugging Rules with openHAB Developer Tools to watch Item-Status](https://youtu.be/EdllUlJ7p6k?t=325)
- [Creating a Blockly Rule](https://youtu.be/EdllUlJ7p6k?t=429)
- [Overview of the Blockly Sections](https://youtu.be/EdllUlJ7p6k?t=558)
- [Logging](https://youtu.be/EdllUlJ7p6k?t=670)
- [Working with Items](https://youtu.be/EdllUlJ7p6k?t=790)
- [Working with Text-Blocks](https://youtu.be/EdllUlJ7p6k?t=975)
- [Sending Commands](https://youtu.be/EdllUlJ7p6k?t=1077)
- [Using Color-Blocks and HSB-Conversion](https://youtu.be/EdllUlJ7p6k?t=1366)
- [Waiting in Rules](https://youtu.be/EdllUlJ7p6k?t=1600)
- [Various Help Documentation available in openHAB Blockly](https://youtu.be/EdllUlJ7p6k?t=1589)
- [Blockly as an ECMA-Script code generator](https://youtu.be/EdllUlJ7p6k?t=1739)
- [Loops in Blockly](https://youtu.be/EdllUlJ7p6k?t=1947)
- [Playing sounds on audio sinks](https://youtu.be/EdllUlJ7p6k?t=2035)
- [Using Text-to-speach easily with blocks](https://youtu.be/EdllUlJ7p6k?t=2395)
- [Streaming Music](https://youtu.be/EdllUlJ7p6k?t=2538)
- [Episode 2](https://www.youtube.com/watch?v=hSRfooBKn9A)
- [Introduction](https://youtu.be/hSRfooBKn9A)
- [Functions](https://youtu.be/hSRfooBKn9A?t=60)
- [Parameters](https://youtu.be/hSRfooBKn9A?t=170)
- [Play Stream](https://youtu.be/hSRfooBKn9A?t=335)
- [IF ELSE](https://youtu.be/hSRfooBKn9A?t=445)
- [Timers](https://youtu.be/hSRfooBKn9A?t=630)
- [Burglar Alarm Example](https://youtu.be/hSRfooBKn9A?t=1046)
- [Disable Rules](https://youtu.be/hSRfooBKn9A?t=1668)
- [Episode 3](https://www.youtube.com/watch?v=KwhYKy1_qVk)
- [Datetimes and Cron-Triggers](https://youtu.be/KwhYKy1_qVk?t=45)
- [Copy-Of, Datetime-Now with Math-Operations](https://youtu.be/KwhYKy1_qVk?t=375)
- [Datetime - Temporal Units](https://youtu.be/KwhYKy1_qVk?t=410)
- [Date comparison](https://youtu.be/KwhYKy1_qVk?t=520)
- [Creating Datetimes and other datetime blocks](https://youtu.be/KwhYKy1_qVk?t=2010)
- [Convert item states to Datetimes](https://youtu.be/KwhYKy1_qVk?t=570)
- [Send Notifications to the openHAB mobile app](https://youtu.be/KwhYKy1_qVk?t=930)
- [Using Ephemeris information](https://youtu.be/KwhYKy1_qVk?t=1275)
- [Using Persistence data](https://youtu.be/KwhYKy1_qVk?t=1440)
- [Wrap up and short overview on basic blocks](https://youtu.be/KwhYKy1_qVk?t=1680)
- [Basic: Logic, Loops, Variables overview](https://youtu.be/KwhYKy1_qVk?t=1730)
- [Basic: Math](https://youtu.be/KwhYKy1_qVk)
- [Basic: Text](https://youtu.be/KwhYKy1_qVk?t=1835)
- [Basic: Lists, Colors](https://youtu.be/KwhYKy1_qVk?t=1910)
- [openHAB Blocks Wrap up](https://youtu.be/KwhYKy1_qVk?t=1945)
- [Global Value Storage](https://youtu.be/KwhYKy1_qVk?t=2060)
- [Run & Process blocks, transform](https://youtu.be/KwhYKy1_qVk?t=2110)
- [Inline Scripts](https://youtu.be/KwhYKy1_qVk?t=2165)
- [Outro](https://youtu.be/KwhYKy1_qVk?t=2257)
## Blocks Overview
Also view ![youtube](../images/blockly/youtube-logo-small.png) [Overview of the Blockly Sections](https://youtu.be/EdllUlJ7p6k?t=558)
### Items and Things
_Items_ and _Things_ are the [major entities of openHAB](https://www.openhab.org/docs/concepts/) to control and monitor the home.
[![Items and Things](../images/blockly/blockly-items-and-things-small.png "Items and Things")
](rules-blockly-items-things.html)
See [Items & Things](rules-blockly-items-things.html) section
### Timers and Delays
Timers and Delays are a little more complex but add important functionality to rules. Whilst the “Wait-For”-block is straightforward, the timer blocks should be well understood before being used - they may behave differently than expected.
This chapter explains what these blocks do, sometimes displaying generated code to explain what is happening behind the scenes.
[![Timers and Delays](../images/blockly/blockly-timers-and-delays-small.png "Items and Things")
](rules-blockly-timers-and-delays.html)
See [Timers and Delays](rules-blockly-timers-and-delays.html) section.
### Voice and Multimedia
This section deals with _playing or streaming audio_ to an audio sink e.g a speaker or _saying a text_ via using any Text-to-Speech API (e.g. Google's API)
[![Voice and Multimedia](../images/blockly/blockly-voice-and-multimedia-small.png "Voice and Multimedia")
](rules-blockly-voice-and-multimedia.html)
See [Voice and Multimedia](rules-blockly-voice-and-multimedia.html) section.
### Units of Measurements
[![Units of Measurement](../images/blockly/blockly-uom-small.png "Units of Measurement")
](rules-blockly-uom.html)
See [Units of Measurement](rules-blockly-uom.html) section.
### Date Handling
Date blocks are used as input parameters for other blocks.
Some of these blocks are used by ephemeris blocks, whilst others are used in the persistence section. Therefore blocks are _typed_ to assure correct connection to other blocks.
[![Date Handling](../images/blockly/blockly-date-handling1-small.png "Dates part 1")
](rules-blockly-date-handling.html) [![Date Handling](../images/blockly/blockly-date-handling2-small.png "Dates Part 2")
](rules-blockly-date-handling.html)
See [Date Handling](rules-blockly-date-handling.html) section.
### Ephemeris
The ephemeris category provides blocks with calendar functionality. The blocks can be used to determine what type of day today is, or a number of days before or after today is.
For example, a way to determine if today is a weekend, a bank holiday, someone’s birthday, trash day, etc.
[![Ephemeris](../images/blockly/blockly-ephemeris-small.png "Ephemeris")
](rules-blockly-ephemeris.html)
See [Ephemeris](rules-blockly-ephemeris.html) section.
### Notifications
For use with your [openHAB cloud](https://www.openhab.org/addons/integrations/openhabcloud/) account, these blocks can be used to send notifications to relevant connected devices.
Notifications can be used as push message to devices running the openHAB client.
[![Notifications](../images/blockly/blockly-notifications-small.png "Notifications")
](rules-blockly-notifications.html)
See [Notifications](rules-blockly-notifications.html) section.
### Persistence
Persistence blocks enable access of historical data stored by the default persistence service.
[![Persistence](../images/blockly/blockly-persistence-small.png "Persistence")
](rules-blockly-persistence.html)
See [Persistence](rules-blockly-persistence.html) section.
### Value Storage
These blocks enable storing information _for a rule_ that is kept after the rule has run, so it can be reused when the rule is run again later in stateful way.
[![Value Storage](../images/blockly/blockly-value-storage-small.png "Value Storage")
](rules-blockly-value-storage.html)
See [Value Storage](rules-blockly-value-storage.html) section.
### Run & Process (Rules, Scripts and Transformations)
This section allows calling rules or other scripts, retrieving attributes provided by the rule context or transforming values via different conversion methods (e.g. map, regex, jsonpath)
[![Run & Process](../images/blockly/blockly-run-and-process-small.png "Run & Process")
](rules-blockly-run-and-process.html)
See [Run and Process](rules-blockly-run-and-process.html) section.
### Logging
This section allows calling rules or other scripts, retrieving attributes provided by the rule context or transforming values via different conversion methods (e.g. map, regex, jsonpath)
[![Logging](../images/blockly/blockly-logging-overview-small.png "Logging")
](rules-blockly-logging.html)
See [Logging](rules-blockly-logging.html) section.
### openHAB Extensions to the Standard
This section explains only the blocks that have been added to the standard blocks by openHAB
[![openHAB Extensions to the standard](../images/blockly/blockly-text-overview-small.png "openHAB Extensions to the Standard")
](rules-blockly-standard-ext.html)[![openHAB Extensions to the standard](../images/blockly/blockly-colors-overview-small.png "openHAB Extensions to the Standard")
](rules-blockly-standard-ext.html)[![openHAB Extensions to the standard](../images/blockly/blockly-lists-dictionary-overview-small.png "openHAB Extensions to the Standard")
![lists-overview-concat](../images/blockly/blockly-lists-concatenate.png)
](rules-blockly-standard-ext.html)
[![openHAB Extensions to the standard](../images/blockly/blockly-bitwise.png "openHAB Extensions to the Standard")
](rules-blockly-standard-ext.html)
See [openHAB Extensions to the standard](rules-blockly-standard-ext.html) section.
### openHAB Blocks provided by the community
The core openHAB are meant to cover most of the functionality that is needed to write rules.
However, there might be functionality that is not available (yet).
These can be provided by the community.
A good explanation on how to write custom blocks can be found at [How to write openHAB Blockly Libraries](https://community.openhab.org/t/tutorial-how-to-write-block-libraries/130074)
All published custom blocks can be found at [Published Blockly Libraries](https://community.openhab.org/c/marketplace/block-libraries/76) and can be directly downloaded within your openHAB installation in the [Settings -> Automation section](/docs/settings/addons.html#automation)
## Tutorials or other useful information
- [Getting Started: Rules - Blockly](https://community.openhab.org/t/getting-started-rules-blockly/132453)
- [Extending Blockly with new openHAB commands](https://community.openhab.org/t/extending-blockly-with-new-openhab-commands/127169)
Reference in New Issue View Git Blame Copy Permalink