Variables in a visualization project
- Reinhard Mayr (Unlicensed)
- Robert Schneider
- Paul Furtak
The Visualization Editor provides means to work with variables. This allows you to reuse visualization elements in a parameterized way. Variables will significantly shorten your visualization development efforts.
Basically, there are two major types of a variable that differ in the point of time when the variable is substituted by a specific value:
design-time substitution: The variable is used in a block that is added to a library. When the block is used, that is, it is dragged from the library listing onto the visualization page, then the user is prompted to provide specific values for the used block variables. This is useful e.g. to prepare a lighting control block in the library. When the block is instantiated on a page then specific parts of ItemIDs are replaced while other properties remain constant.
run-time substitution: The variable is used in a visualization element. When the element is displayed, the variable is substituted by its specific value. Variables of this kind can be defined for layers, pages, groups and other visual elements.
Variables for design-time substitution
Code | Syntax | Description |
|---|---|---|
BK | {BK:<var name>} | Defines a block variable. |
Block variables are replaced during design-time when a library element is instantiated on a visualization page.
Set up the library-element-to-be and insert the variable syntax when needed, e.g. as part of an item ID.
Add the element to the library
Use the library element by dragging it onto the page. You will be prompted to enter specific values for the used block variables:
All occurrences of variables in the inserted block are replaced by the provided values.
Variables for run-time substitution
Click menu Views → Variables to show the Variables pane. It contains a list of variables available to the current selection. Following variable types are available:
Code | Syntax | Description | Notes |
|---|---|---|---|
MA | {MA:<var name>} | Variable of parent object (sequence: GR/LA/PG/WS) |
|
GR | {GR:<var name>} | Variable of a group object |
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LA | {LA:<var name>} | Variable of a layer object |
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PG | {PG:<var name>} | Variable of a page object |
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WS | {WS:<var name>} | Variable of a workspace object |
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OB | {OB:<var name>} | Variable of the current graphic object |
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OV | {OV:<graphic object id>.<var name>} {OV:this.<var name>} | Object variable of the graphic object with the given ID. The referenced object has to be on the same visualization page as the referencing object. Use "this" for the <graphic object id> to get properties of the current object. | |
IV | {IV:<Item ID>} {IV:this} | Item value "this" uses the value of the last item ID written to the control | |
IP | {IP:<Item ID>.<Property ID>} {IP:this.<Property ID>} | Value of an item’s property (e.g. "this" uses the last item written to the control | |
CH | {CH:<character code>} | Special character. Possible character codes are
| |
SV | {SV:<var name>} | System variable. Possible variable names are
| available since 4.2.2061 |
VT | {VT:<key>.<index value>} | Variable of Excel file nxaVarTable.xslx (in Visualization project's DataFiles folder) | available since 4.1.2000 |
OT | {OT:<index value>} | The control name must be identical with the variable name within the first column of the Excel file. | available since 4.1.2000 |
EV | {EV:<mathematical expression>} | Evaluates a mathematical expression, e.g. {EV:"(500+200)/{PG:Eval}"}adds the constants 500 and 200 and divides the result by the value of the page variable (PG) "Eval". The original expression is replaced by the arithmetic result before further processing. | available in web from 4.1.2010 internally, a .NET DataColumn.Expression is used |
TT | {TT:<translation key>} | Yields the translation of the provided translation key depending on the value of the NXA_LANGUAGE workspace variable. | available since 4.2.1010 |
PR | {PR:<prop name>} | Property value of the current graphic object (e.g. | available since 4.2.1000 |
OP | {OP:<graphic object id>.<prop name>} {OP:this.<prop name>} | Property value of the graphic object (e.g. The referenced object has to be on the same visualization page as the referencing object. Use this for the graphic object id to get properties of the current object. | available since 4.2.1000 |
IE | {IE:<Item ID>} | Item Exists - Variable provides existence of Item ID or Item Branch. (e.g. | available since 4.2.2065 |