REDCap now supports Action Tags

Action Tags are special terms that begin with the '@' sign that can be placed inside a field's Field Annotation. Each action tag has a corresponding action that is performed for the field when displayed on data entry forms and survey pages. Such actions may include hiding or disabling a given field (either on a survey, data entry form, or both). Below is a comprehensive list of all available action tags that you may use. You can use as many as you want for a single field, but if you do use more than one tag for a field, make sure to put a space or line break between them. Because the action tags are used as part of the Field Annotation, they are not displayed anywhere on the page.

For example, if you put @HIDDEN-SURVEY in a field's Field Annotation text box, then the field will always stay hidden when viewed on a survey page, but the field will be visible when viewing the same instrument as a data entry form, which might be helpful if you want to hide specific fields from your survey participants so that they do not see them. There are many different use cases for each action tag.

These are the action tags available in REDCap version 9. For an up to date list, see your REDCap system help pages.

@APPUSERNAME-APP 

In the REDCap Mobile App, it sets a field's value to the app username of the current mobile app user - i.e., their username in the mobile app, which is not necessarily the same as their REDCap server username that can be captured using @USERNAME. NOTE: For use only in the REDCap Mobile App.

@BARCODE-APP

Allows the REDCap Mobile App to capture the value of a barcode or QR code by scanning it with the device's camera. NOTE: For use only in the REDCap Mobile App.

@CHARLIMIT

Sets the maximum number of characters that can be entered into a Text field or Notes field, and also displays the number of characters remaining. The format must follow the pattern @CHARLIMIT=??, in which ?? is the desired max character count (alternatively, the number value can be inside single or double quotes). NOTE: This action tag cannot be used at the same time as @WORDLIMIT for the same field. NOTE: This action tag does *not* get applied during any data imports (via API or Data Import Tool) but only operates when viewing survey pages and data entry forms.

@DEFAULT

Sets a field's initial value. This allows a field to have a specified default value when viewing the field on a survey or data entry form that has not yet had any data saved for it (i.e., when the form status icon is gray or when a survey page has not had any data entered yet). The format must follow the pattern @DEFAULT="????", in which the desired default value should be inside single or double quotes. For checkbox fields, simply separate multiple checkbox values with commas - e.g., @DEFAULT='1,3,6'. For text fields, you may even perform Piping inside the default value to pipe data from another field in the project - e.g., @DEFAULT='Name: [first_name] [last_name], DOB: [dob]'. NOTE: The default value does *not* get applied during any data imports (via API or Data Import Tool) but only operates when viewing survey pages and data entry forms. NOTE: If being used on a date or datetime field, the date value inside the quotes must be in Y-M-D format - e.g., @DEFAULT='2007-12-25' - regardless of the field's set date format.

@HIDDEN

Hides the field on the survey page, the data entry form, and in the REDCap mobile app. Field will stay hidden even if branching logic attempts to make it visible.

@HIDDEN-APP

Hides the field only on the form ONLY on the REDCap Mobile App. Field will stay hidden even if branching logic attempts to make it visible.

@HIDDEN-FORM

Hides the field only on the data entry form (i.e., not on the survey page). Field will stay hidden even if branching logic attempts to make it visible.

@HIDDEN-SURVEY

Hides the field only on the survey page (i.e., not on the data entry form). Field will stay hidden even if branching logic attempts to make it visible.

@HIDEBUTTON

Hides the 'Now' or 'Today' button that is typically displayed to the right of date, time, and date/time fields.

@HIDECHOICE

Hides one or more choices of a multiple choice field. This action tag is useful if you wish to retire a particular choice after utilizing it for a while in data collection, thus allowing you to hide the choice from that point afterward without orphaning any of the choice's data, which would happen if you simply deleted the choice. The format must follow the pattern @HIDECHOICE='??', in which the coded values should be inside single or double quotes for the choice(s) you wish to hide. If more than one choice needs to be hidden, then provide all the coded values separated by commas. For example, to hide the choice 'Monday (1)', you would have @HIDECHOICE='1', but if you wanted to additionally hide 'Tuesday (2)', you would have @HIDECHOICE='1,2'. NOTE: If the hidden choice has already been selected for a given record, then the choice will not be hidden on the survey or form for that record/event. NOTE: Hidden choices will still appear in reports and data exports. NOTE: This action tag can only be utilized for the following field types: Checkbox, Radio, Drop-down, Yes-No, and True-False. NOTE: This action tag works only in limited fashion with a matrix of fields, in which it will simply hide the checkbox/radio for a field in the matrix but still display the column for that choice in the matrix.

@LATITUDE

Allows a Text field field to capture the latitude of the user, in which the user will be prompted on the webpage to allow or deny this. Once the value is captured, it will not be changed when visiting the page at a later time. The field will be disabled and will not allow users to edit the value, but it will allow them to remove the value altogether. NOTE: While the GPS value will be very accurate when captured on a mobile device, it will not be nearly as accurate when using a browser on laptops and desktop computers.

@LONGITUDE

Allows a Text field to capture the longitude of the user, in which the user will be prompted on the webpage to allow or deny this. Once the value is captured, it will not be changed when visiting the page at a later time. The field will be disabled and will not allow users to edit the value, but it will allow them to remove the value altogether. NOTE: While the GPS value will be very accurate when captured on a mobile device, it will not be nearly as accurate when using a browser on laptops and desktop computers.

@MAXCHECKED

Allows a checkbox field to have a maximum number of checkboxes that can be checked. If other checkbox options are clicked after the maximum has been reached, those choices will not be able to be checked. The format must be @MAXCHECKED=#, in which # is a positive integer. For example, @MAXCHECKED=3 will allow a maximum of 3 checkbox choices to be checked. NOTE: This action tag can only be utilized by Checkbox fields, and it does not get enforced during data imports.

@MAXCHOICE

Causes one or more specified choices to be disabled (i.e., displayed but not usable) for a checkbox, radio button, or drop-down field after a specified amount of records have been saved with that choice. For example, @MAXCHOICE(0=50,1=75,2=50) would imply that once 50 records have selected the '0' coded choice, that choice will become disabled for any record viewed afterward that does not have that choice saved, such as when the form/survey is opened for a new record, and thus 75 records for choice '1', 50 for choice '2', etc. The format must be the action tag name followed by the choice designations inside parentheses, in which each will follow the format of ChoiceCode=MaxCount with each choice separated by commas. Note: For longitudinal projects, when counting the number of choices saved for records, it will treat all events as separate, meaning that in the example above, choice '0' can have a max number of 50 selections in EACH event in the project.

@NONEOFTHEABOVE

Allows for the designation of a checkbox choice to be a 'none of the above' option, thus ensuring that no other choices are checked if that one choice is selected. This means that if that particular option is selected, it will alert the user that all other checked-off choices will be unchecked. And if the 'none of the above' option is already checked when the user checks off another choice, it will automatically uncheck the 'none of the above' option. This action tag makes it possible to have a 'none of the above' option without the risk of users mistakenly having other choices selected at the same time. The format must follow the pattern @NONEOFTHEABOVE=??, in which ?? is the coded value of the 'none of the above' checkbox choice - e.g., @NONEOFTHEABOVE=98. Alternatively, it is possible to set multiple options as a 'none of the above' option at the same time, in which the coded values must be comma delimited inside single or double quotes - e.g., @NONEOFTHEABOVE='45,99'. This is useful for certain situations, such as if you have a 'none of the above' option and also have a 'refuse to answer' option, thus allowing either of those to be the only option that can be selected at a time. NOTE: This action tag can only be utilized by Checkbox fields.

@NOW (e.g., 2017-08-01 12:34:56)

Loads the current user's date+time into a blank Text field - similar to the @TODAY tag but additionally includes the time portion. If the field has validation, the value will adjust to match the date format. NOTE: The time used will be the user's local time, which is derived from their device/computer and might be different from the server if in another timezone. Also, do not use this tag on fields with branching logic because it will always prompt the user to erase the value, so look at using @HIDDEN instead if you wish to hide the field.

@PASSWORDMASK

Masks the value of a Text field so that the true value is not visible on the webpage after it has been entered (like password fields on login pages)

@PLACEHOLDER

Is used to specify a short hint that describes the expected value of a Text field or Notes field (e.g. a sample value or a short description of the expected format). The placeholder is displayed inside the field before a value is entered. The format must follow the pattern @PLACEHOLDER='????', in which the text to be displayed should be inside single or double quotes.

@RANDOMORDER

Randomizes the order of multiple choice field options as displayed on survey pages and data entry forms, in which their order will always be different each time the page is loaded by any given user. NOTE: This action tag can only be utilized for the following field types: Checkbox, Radio, Drop-down, Yes-No, and True-False. This tag also works for enhanced radios and checkboxes on surveys. However, this tag does *not* work for a matrix of fields.

@READONLY

Makes the field read-only (i.e., disabled) on the survey page, the data entry form, and in the REDCap mobile app so that its value cannot be changed.

@READONLY-APP Makes the field read-only (i.e., disabled) on the form ONLY on the REDCap Mobile App so that its value cannot be changed.

@READONLY-FORM

Makes the field read-only (i.e., disabled) only on the data entry form (i.e., not on the survey page or mobile app) so that its value cannot be changed.

@READONLY-SURVEY

Makes the field read-only (i.e., disabled) only on the survey page (i.e., not on the data entry form or mobile app) so that its value cannot be changed.

@SYNC-APP

Can be used only for File Upload and Signature fields. If the project is initialized in the REDCap Mobile App, this will cause any image files uploaded to a record to be sent to the app so that they are viewable in the app when editing the record. NOTE: For use only in the REDCap Mobile App.

@TODAY (e.g., 2017-08-01)

Loads the current user's date into a blank Text field - similar to the @NOW tag but without the time portion. If the field has validation, the value will adjust to match the date format. Also, do not use this tag on fields with branching logic because it will always prompt the user to erase the value, so look at using @HIDDEN instead if you wish to hide the field.

@USERNAME

Sets a field's value to the username of the current REDCap user. If this is used on a survey, the value will be '[survey respondent]'. Once the value is captured, it will not be changed when visiting the page at a later time.

@WORDLIMIT

Sets the maximum number of words that can be entered into a Text field or Notes field, and also displays the number of words remaining. The format must follow the pattern @WORDLIMIT=??, in which ?? is the desired max word count (alternatively, the number value can be inside single or double quotes). NOTE: This action tag cannot be used at the same time as @CHARLIMIT for the same field. NOTE: This action tag does *not* get applied during any data imports (via API or Data Import Tool) but only operates when viewing survey pages and data entry forms.