How to Add a Custom Table Footnote

This article describes how to go from a standard table...

...to a table that appends a custom note to the table footer....

...and additionally matches a cell marker to signify low sample size...

...or points of interest:

Requirements

• A table with columns
• You have read How to Create a Custom Rule

Please note this requires the Data Stories module or a Displayr license.

Method - Add text to footer

1. Select your table.

2. Go to Appearance > RULES on the object inspector.

3. Click the Plus (+) button. 

4. Click New custom rule (write your own JavaScript) > Edit JavaScript.

5. Paste the below into the dialog:

form.setHeading("Add custom footnote");
form.setSummary("Add custom footnote");

var footers = table.extraFooters;
footers.push("Warning: Some cells are less than 100");
table.extraFooters = footers;

• In this code, we first pull the existing footer text and declare it as footers.
• We then use the push function to append our text to this variable.
• Finally, we set our table footer with the updated footers variable.

6. Press the Play button > OK > OK.

Method - Less than a specified threshold

1. Select your table.

2. Go to Appearance> Rules on the object inspector.

3. Click the Plus (+) button. 

4. Click New custom rule (write your own JavaScript) > Edit JavaScript.

5. Paste the below into the dialog:

form.setHeading("Add custom footnote");
form.setSummary("Add custom footnote");

var target = 100;
table.addFootNoteForCellsLessThan('Column Sample Size', target, '*', '* sample size <' + target);

7. Press the Play button > OK > OK.

Method - Identify columns of interest

form.setHeading("Add custom footnote");
form.setSummary("Add custom footnote");

var target_column_labels = ['25 to 34','35 to 49'];
for (var i = 0; i < target_column_labels.length; i++) {
  var column = table.columnIndex(target_column_labels[i]);
  // Confirm that the column index was found. If not found, the index will be -1.
  if (column != -1) {
  // Yes, it was found. Now go through each row in the column,
  // adding the footnote marker.
  for (var row = 0; row < table.numberRows; row++)
    table.addFootNote(row, column, '*', null, '* This is our target market');
  }
}

• In this code, we first set the target column labels to apply the condition to. These must match those in the table.
• Next, we loop through each column until we find the specified column labels.
• We then loop through the rows and use the addFootNote function to pass the following arguments: row index, column index, footnote marker, index of statistic to display marker next to, and footnote text. 
• The text from the last argument will be added to the footer text and the marker will be added to all cells within the specified columns.

3. OPTIONAL: Change target_column_labels to refer to the appropriate column labels in your table.

4. OPTIONAL: Change the marker argument in addFootNote to specify a different character.

5. OPTIONAL: Change the index of statistic to display marker next to argument in addFootNote by using the zero-based index. Here. we will set this to null in order to place the marker alongside the first statistic.

6. OPTIONAL: Change the footnote text argument in addFootNote.

7. Press the Play button > OK > OK.

Next

How to Custom Sort Tables

See Also

How to Use Rules in Displayr

How to Customize a Rule

How to Create a Custom Rule

How to Add a Footnote for Cells with Small Sample Sizes

How to Add a Column Header Footnote Indicating Small Sample Sizes