Function Repository Resource:

ValidatedInputField

Create an input field that handles erroneous inputs gracefully and responds to the Enter/Return key

Contributed by: Jayanta Phadikar

ResourceFunction["ValidatedInputField"][Dynamic[var],test,msg]

creates an editable input field with dynamically updated field value var, that performs a validity check for the input using test and shows msg in case the test fails.

ResourceFunction["ValidatedInputField"][Dynamic[var],test,msg,action]

creates an input field that performs action when Enter/Return is pressed.

Details

The function accepts an argument test that represents a validity check for the input value. If the input is not valid, an error dialog is displayed containing the message msg.

The input is interpreted as a Wolfram Language expression. Therefore, entering a sequence of letters is interpreted as a symbol name, rather than a string.

An optional task can be specified using action which will be executed after typing in the value and hitting Enter/Return.

ResourceFunction["ValidatedInputField"] accepts most of the options of the built-in InputField.

Examples

Basic Examples (2)

Create an input field that accepts a number between 0 and 10; trying to enter a value outside the range will result in an error message:

In[1]:=

DynamicModule[{x = 5},
ResourceFunction["ValidatedInputField"][
Dynamic[x], (NumberQ[#] && (0 <= # <= 10)) &, "Please enter a number between 0 and 10"]
]

Out[1]=

An input field that prints the current number upon hitting Enter/Return:

In[2]:=

DynamicModule[{x = 10},
ResourceFunction["ValidatedInputField"][Dynamic[x], NumberQ[#] &, "",
Print[x]]
]

Out[2]=

Options (8)

Appearance (1)

Change the appearance:

In[3]:=

Out[3]=

BaselinePosition (1)

Set the baseline position:

In[4]:=

Out[4]=

Enabled (1)

Disable the input field:

In[5]:=

Out[5]=

FieldMasked (1)

Mask the contents:

In[6]:=

DynamicModule[{x = 1000},
ResourceFunction["ValidatedInputField"][Dynamic[x], NumberQ[#] &, "Please enter a number", Echo["Secret number recorded"], FieldMasked -> True]
]

Out[6]=

FrameMargins (1)

Set a larger frame margin:

In[7]:=

Out[7]=

ImageMargins (1)

Set a larger image margin:

In[8]:=

Out[8]=

FieldSize (1)

Alter the field size:

In[9]:=

Out[9]=

ImageSize (1)

Alter the image size:

In[10]:=

Out[10]=

Applications (2)

Show an error dialog when an entered value for a plot range is not a number or is less than zero:

In[11]:=

DynamicModule[{xr = 10, yr = 10, msg},
msg = "Please enter a number greater than 0";
Column[{
Row[{"Range x: ", ResourceFunction["ValidatedInputField"][
Dynamic[xr], (NumberQ[#] && # > 0) &, msg]}],
Row[{"Range y: ", ResourceFunction["ValidatedInputField"][
Dynamic[yr], (NumberQ[#] && # > 0) &, msg]}],
Dynamic[
Plot3D[Sin[x] Cos[y], {x, 0, xr}, {y, 0, yr}, ImageSize -> Medium]]
}]
]

Out[11]=

Show an error dialog when an entered radius is not a number between 1 and 2:

In[12]:=

DynamicModule[{disks, rad = 1.5}, disks = {RandomColor[], Disk[RandomReal[{-18, 18}, 2], 1]}; Column[{
ResourceFunction["ValidatedInputField"][
Dynamic[rad],
(NumberQ[#] && # >= 1 && # <= 2) &,
"Please enter a number between 1 and 2",
disks = Append[disks, {RandomColor[], Disk[RandomReal[{-18, 18}, 2], rad]}]
],
Spacer[10],
Framed[
Graphics[Dynamic[disks], PlotRange -> {{-20, 20}, {-20, 20}}, ImageSize -> Medium]]
}]
]

Out[12]=

Properties and Relations (2)

The built-in InputField responds to Enter/Return only when the value is changed. The following prints the value in the input field for a new value only:

In[13]:=