Wolfram Function Repository
Instant-use add-on functions for the Wolfram Language
Function Repository Resource:
Determine if an expression is a valid front end object
ResourceFunction["FrontEndObjectQ"][expr,t] requires expr to be a valid front end object of type t. |
NotebookObject[…] | a currently open notebook |
CellObject[…] | a cell in an open notebook |
BoxObject[…] | a particular box in a cell |
$FrontEnd | an object representing global settings for the front end |
NotebookObject | checks if expr is a valid NotebookObject |
CellObject | checks if expr is a valid CellObject |
BoxObject | checks if expr is a valid BoxObject |
patt | checks if expr matches the given pattern and is a valid front end object |
"type" | checks if expr is a valid front end object of the named type |
{t1,…,tn} | checks if expr is a valid front end object and has type matching one of the ti |
"Notebook" or "NotebookObject" | NotebookObject |
"Cell" or "CellObject" | CellObject |
"Box" or "BoxObject" | BoxObject |
A NotebookObject that corresponds to a currently open notebook is a valid front end object:
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If the notebook is closed, it's no longer valid:
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Test if a CellObject is valid:
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If the cell is deleted, it's no longer valid:
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FrontEndObjectQ also works with BoxObject:
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Delete one of the boxes:
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Now only one of the boxes is valid:
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Test for a valid cell object:
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Accept only cells and boxes:
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Use a named type:
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Use a pattern:
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When a front end is available, $FrontEnd corresponds to a valid front end object:
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When evaluated in a standalone kernel, $FrontEnd does not correspond to a valid front end object:
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The full form of a valid cell object is CellObject[id], where id is an integer that corresponds to a serial number that is unique to that cell for the front end session:
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Not all expressions of the form CellObject[id] are valid front end objects:
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The full form of a valid box object is BoxObject[id], where id is an integer that corresponds to a serial number that is unique to that box structure for the front end session:
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Not all expressions of the form BoxObject[id] are valid front end objects:
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$FrontEndSession and $DefaultFrontEnd are symbols that represent particular front end states and are valid front end objects:
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These have options just like many other front end objects:
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If a cell is overwritten with another cell, it will be represented by a new CellObject:
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Overwrite the cell with an identical copy:
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The new cell has replaced the old one:
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Check the serial numbers:
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To preserve cell objects, overwrite the contents of cells instead of the cells themselves:
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Get a random BoxObject:
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View the box contents:
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Find the enclosing cell:
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View the cell contents:
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Get the notebook that contains the cell:
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Get the front end that owns the notebook:
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These are all valid front end objects:
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