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FieldCompletionFunction

is an option for InputField that specifies a function to apply to the input field's contents to generate a list of completions.

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FieldCompletionFunction

FieldCompletionFunction

is an option for InputField that specifies a function to apply to the input field's contents to generate a list of completions.

Details

  • The default value of FieldCompletionFunction->Automatic indicates that there will be no completion menu for the input field.
  • When a field completion function is specified, the front end will call the function with the current contents of the InputField. If the result of calling the function is a List, then the front end will display the elements of the list in a completion popup menu, which is typically positioned immediately below the input field.
  • If the completion function returns an empty list, no menu will be displayed.
  • The completion function will be called after every keystroke, even if ContinuousAction->False has been set.

Examples

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Basic Examples  (2)

Create an input field that offers a fixed set of completions:

Wolfram Language code: InputField[1, FieldCompletionFunction -> ({"fish", "fowl"}&)]

Use a completion function that modifies the existing input:

Wolfram Language code: InputField["a", String, FieldCompletionFunction -> ({# <> "?"}&)]

Applications  (2)

Create an input field that offers filename completions:

Wolfram Language code: InputField["", String, FieldCompletionFunction -> (FileNames[FileNameTake[#] <> "*", {DirectoryName[#]}]&)]

Create an input field that offers completions of all matching System` functions:

Wolfram Language code: InputField[N, FieldCompletionFunction -> (Names["System`" <> ToString[#] <> "*"]&)]

Possible Issues  (1)

A completion function that returns one item will not work if it is not wrapped in a list:

Wolfram Language code: InputField[1, FieldCompletionFunction -> ("the completion"&)]

The solution is to simply wrap it in a list:

Wolfram Language code: InputField[1, FieldCompletionFunction -> ({"the completion"}&)]
Wolfram Research (2017), FieldCompletionFunction, Wolfram Language function, https://reference.wolfram.com/language/ref/FieldCompletionFunction.html.

Text

Wolfram Research (2017), FieldCompletionFunction, Wolfram Language function, https://reference.wolfram.com/language/ref/FieldCompletionFunction.html.

CMS

Wolfram Language. 2017. "FieldCompletionFunction." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/FieldCompletionFunction.html.

APA

Wolfram Language. (2017). FieldCompletionFunction. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/FieldCompletionFunction.html

BibTeX

@misc{reference.wolfram_2026_fieldcompletionfunction, author="Wolfram Research", title="{FieldCompletionFunction}", year="2017", howpublished="\url{https://reference.wolfram.com/language/ref/FieldCompletionFunction.html}", note=[Accessed: 12-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_fieldcompletionfunction, organization={Wolfram Research}, title={FieldCompletionFunction}, year={2017}, url={https://reference.wolfram.com/language/ref/FieldCompletionFunction.html}, note=[Accessed: 12-June-2026]}