Common features of the WebStudio widgets.
Every widget needs to have a unique id
. In case no id
is set, WebStudio will generate one automatically. Feel free to adjust the id
as long it is unique.
{
"type": "widget type",
"id": "yLtC", // Unique identification of the widget.
"name": "NAME", // Will be shown in the caption bar.
"description": "",
"layout": {
"w": 7,
"h": 15,
"x": 0,
"y": 0,
"locked": false
}
}
In case layout
is not provided, WebStudio will try to auto layout the widget.
To hide the caption bar:
{
"captionBar": false
}
Advanced properties:
{
"captionBar": {
"hidden": true,
"title": "Widget Title", // Will be used instead of the name field.
"showModelEditorButton": false
}
}
When title
is not defined, the title will be "name
" or type
when name
is not defined.
When showModelEditorButton
is set to false, the editor of the widget becomes unavailable.
refreshInterval
lets the widget automatically refresh. Value is given in seconds. Minimum value is 0.5 seconds. The value 0 means that the refresh interval is disabled.
Every widget can be styled by setting the style
object. The style
object accepts a wide range of CSS styles. The CSS properties are only accepted in camelCase. Some examples:
{
"options": {
"refreshInterval": 10,
"style": {
"backgroundColor": "transparent",
"border": "1px solid blue"
}
}
}
Other border
options are:
none
1px dashed red
1px dotted white
4px double grey
5px ridge white
3px solid blue
See more over here CSS Borders.
The widgets can perform logic in the form of actions. This can be a single action or a sequence of actions which we call an action pipeline. The data which is passed to and from one action to the other is called a message.
Actions can be defined within the actions field and in specific parts in the model. This is documented per widget type.
Performing multiple pipelines in parallel can be achieved by defining multiple arrays on the pipeline field.
The input message of a pipeline action contains:
{
"topic": "", // Could be provided by the widget.
"payload": {} // Typically an object.
}
The payload
can be any type. Keep in mind that in order to be able merged with the input message it needs to be an object. The topic
tells the executing / receiving widget what to do with the payload
.
In case the output of an action doesn't return an object with topic
or a payload
the output will be set to the input message payload
of the next action.
With the next example only the payload is provided to the action.
{
"type": "ACTION_TYPE"
}
In order to merge additional fields into the payload
a pipeline action can be defined like:
{
"type": "ACTION_TYPE",
"message": {
"payload": {
"additionalValue": 42
}
}
}
In order to merge additional fields into the message a pipeline action can be defined like:
{
"type": "ACTION_TYPE",
"message": {
"payload": {
"additionalValue": 42
},
"additionalField": "Hello"
}
}
If you want to skip an action step during testing you can set the skip
field to true
.
Data sources can be defined in the widget model to fetch and write data from and to the system. It can also be an action pipeline.
Obvious actions:
function
: Invokes an Advanced Endpoint.read
: Reads the dynamic value or a property value of an object.read-write
: Reads and writes the dynamic value or a property value of an object.subscribe
: Subscribes to theOnDataChanged
event of a dynamic value.write
: Writes the dynamic value or a property value of an object.
Typically a dataSource
has a single action.
{
"dataSource": {
"type": "read",
"path": "/System/Core/Examples/Variable"
}
}
In order to transform
the output message of the read
action, an action pipeline can be defined.
{
"dataSource": [
{
"type": "read",
"path": "/System/Core/Examples/Variable"
},
{
"type": "transform",
"aggregateOne": [] // See transform docs.
}
]
}
To invoke an Advanced Endpoint. The payload
in the output contains the data returned by the Advanced Endpoint.
{
"dataSource": {
"type": "function",
"lib": "LIBRARY NAME",
"func": "FUNCTION NAME", // Optional function name in case library is Lua table.
"farg": {}, // Optional function argument.
"ctx": "" // Optional system object path.
}
}
Reads the dynamic value of an object or the value of an object property. The payload
in the output contains the dynamic or property value.
{
"dataSource": {
"type": "read",
"path": "/System/Core/Examples/Demo Data/Process Data/FC4711"
}
}
Reads and writes the dynamic value of an object or the value of an object property.
{
"dataSource": {
"type": "read-write",
"path": "/System/Core/Examples/Demo Data/Process Data/FC4711"
}
}
Subscribes to the OnDataChanged
event of a dynamic value. The payload
in the output contains the dynamic value.
{
"dataSource": {
"type": "subscribe",
"path": "/System/Core/Examples/Demo Data/Process Data/FC4711"
}
}
The actions
is an object which fields are known hooks, like the Life Cycle Hooks, or custom action names. The value can be a single action object or an array with action objects.
{
"actions": {}
}
Widgets supports life cycle hooks. During loading, updating and refreshing many hooks are invoked. Hooks can contain any number of pipeline actions.
Overview of all the general hooks:
didLoad
: Widget loaded on screen.willUpdate
: Widget will update view.didUpdate
: Widget did update view.willRefresh
: Widget will perform a refresh.didRefresh
: Widget did perform a refresh.willFetch
: Widget will perform a fetch.didFetch
: Widget did perform a fetch.
The hookswillFetch
and didFetch
are only invoked if the widget has a data source defined. Note that some widgets have root properties, like path
on a Faceplate widget, which are considered as a data source.
The load life cycle flow is:
didLoad
willFetch
Execution of the data source action (pipeline)didFetch
willUpdate
Screen updateddidUpdate
The refresh life cycle flow is:
willRefresh
willFetch
Execution of the data source action (pipeline)didFetch
willUpdate
Screen updateddidUpdate
didRefresh
Refresh can be executed by e.g. a refresh button, refresh interval and send action.
The update life cycle flow is:
willUpdate
Screen updateddidUpdate