Logic Dictionary

This page includes a basic break down of all the different logic commands available in the authoring tool along with basic examples to illustrate.

Key Commands (text in red) and Commands (text in pink) should be written as they appear in the examples.

Key commands (red)

after

The after key command is used after a page to perform functions that relate to that page.

The most common way of user the after key command is with the if and goto key commands in the following formula:

show page1

after page1 if (any commands you want to relate to this page) goto page2

Example

after page1 if (any functions you want to relate to this page) goto page2

Note: the after key command is also used at the end of the logic formula for save and graph

begin

The begin key command is always used with the end key command

If your intervention has separate sessions or groups (e.g. different weekly sessions in your behavioural intervention, or a different set of pages for different user groups) then splitting your pages into sections can make it easier for you to organise parts of your intervention and find sections easily.

Things to remember when splitting you intervention into sections:

• If you begin a section, you should always end the section.
• All the logic related to the section must be between begin sectionname and end
• The name of the section should not be the same as any unique name that has been given to an object or page in your intervention.
• As you can only ever end the section that you are currently in you do not need to write the section name after end.

Example 1

begin session1

show page1

show page2

end

This will begin session1, show page1 and page2, and will end session1. All the pages related to session1 (page1 and page2) are between begin session1 and end.

Example 2 – Beginning and ending a section within another section

begin stress

begin causes

show page1

show page2

end

begin relieve

show page3

show page4

end

end

This will begin the section stress. The section causes will then begin and page1 and page2 in the section causes will be shown. he first end will end the section causes. The section relieve will then begin and page3 and page4 will be shown. The next end will end the section relieve. The final end will end the section stress.

end

See begin

for

The for key command is used with the save and graph key commands.

goto

The goto key command always follows the after key command. See above.

graph

The graph key command is used when you have used the graph interaction. It is used to plot the information given by end-users to the graph.

This key command always follows the same formula and requires users to set up a user account.

graph value to "data variable determined on the graph interact" for unique identifier for the end-user e.g. username after the page that the value has been generated from

Another line of logic is then needed for the page where the graph occurs. This will also always follow the same formula:

set pagename.graph-1 to graph "data variable determined on the graph interact" for username

Here, pagename.graph-1 is the automatically generated name of the graph that has been put on the page where the graph occurs.

Example1

In this example the number entered in the interaction ‘kg’ on the page ‘progresschart’ will be used as the data for the “weight” variable for the graph. The variable username has been set earlier in the logic as the unique identifier for the end-user (see the set key command for more information).

show progresschart graph progresschart.kg to "weight" for username after progresschart

Later in the logic the following line is needed after the page where the graph occurs:

show weightgraph set weightgraph.graph-1 to graph "weight" for username

A full tutorial for using graphs will soon be available.

if

The if key command is always used with the set or after key commands.

named

Use this key command to re-show a page you have already shown.

For example, if you had a page that you need to keep showing back to your users you could use the named key command as so (note that in the example below the line [etc, etc] has been used to indicate that there would be other lines of logic here).

Example

show page1

[etc, etc]

show page1 named page2

[etc, etc]

show page1 named page3

set

The set key command can be used to set variables within the logic or for performing calculations.

Example 1

The most common use of setting variables will be to set a username for the user. Many of the logic commands such as save will need a username to be set. This will need to be done at the start of your logic file.

Set username to login.loginuname

This will set the variable username to whatever the end-user enters into the interaction uniquely named loginuname on the login page. The word username can then be used any time throughout the logic to mean whatever the person entered in that interaction.

Example 2

The set key command can also be used to set a variable based on how end-users respond to certain interactions. This can then be used to tailor the intervention based on this variable.

show page1

set condition1 to and (page1.chooseoptions contains "optiona", page1.chooseoptions contains "optiond")

after page1 if condition1 goto page3

So in example 2, the variable ‘condition1’ is set if end-users select options a and d from the interaction ‘chooseoptions’ on page1. Then those that are in this condition are sent to page 3 where they will receive tailored information based on the options they selected.

Example 3

In this example, the set key command is used to set a score based on the calculation that follows. In this calculation the number that the end-user selects in the interaction ‘dailyexercise’ on page1 is multiplied by 5 to create their exercise score

set exercisescore to (page1.dailyexercise * 5)

show

The show key command is the first and most important logic command you will need to know. It is also probably the most common one that you will use.

This key command shows each of the pages that you have created. Pages will be shown in the order they are mentioned in the logic. When an end-user clicks on a Next button on a page, they will be moved to the next page written in the logic.

Example 1

show page1

show page2

show page3

show page4

In the example above the end-user will first be presented with the page uniquely named ‘page1’. Then, when they click on the next button on page1 they will see the page called ‘page2’. This is followed by ‘page3’ and finally ‘page4’.

Note: Before you can preview your intervention you will need to have the show key command in the logic file for each page you want to view.

As the logic requires you to use unique names for each page in your logic, you can only use the show key command once for each page. However, see the named key command above for how to re-show the same page to users.

You can also reshow pages to your end-user by using a jump button on a previous page.

to

The to key command is used with the set key command to set variables.

Commands (pink)

add

The add command is used when performing calculations in the logic. This may also be written as sum or +).

Example 1

This can be used to perform a calculation using the end-user's responses to specific numeric value interactions:

set score1 to add (page1.interaction1, page1.interaction2, page1.interaction3)

Example 2

The add or sum commands can also be used to calculate variables that have been set earlier in the session:

set overallscore to sum (score1, score2, score3)

and

The and command can be used for a number of reasons:

1. . if there is more than one response that is involved in presenting tailored advice to end-users, i.e. if one response and another response is needed to show feedback to an end-user.
2. . if you need to perform a number of logic commands after a page

Example 1

show page6 if (and(page3.exercise = yes, page3.intensity = moderate, page3.frequency = three)

End-users will be shown pagename6 if they selected yes to the interaction exercise on page3, moderate to the interaction intensity on page3 and three to the interaction frequency on page3.

Example 2

append

The append command allows you to attach strings of logic together or to attach a variable within a string.

Example 1

In this example the append function is used to attach a person's username (which has been set in a previous part of the logic) to the text used in an email message:

after login if sendemail ("welcomeemail", login.uname, "Welcome to the lifestyle study", append ("Thank you for registering for the study", username, "remember to chart your progress everyday"), 60) goto page1

authenticateuser

This is important logic for ensuring that a user is registered with the intervention and is usually found after the login page of an intervention.

The authenticateuser command can be used in the logic (intervention.lgil) file or in the error message logic.

cancelemail

This command is used to cancel an email that has already been set up earlier on in the logic. For example if you set up e-mail reminders for people to login to upcoming sessions in the intervention then you will need to then cancel them if they subsequently login before the e-mail is due to be sent out.

This command uses the same basic formula:

after pagename if cancelemail ("unique name for email", e-mail address) goto nextpage

Example

after session2welcome if cancelemail ("session 2 reminder", login.email) goto session2page1

cancelsms

This command cancels an SMS message that has already been set up earlier on in the logic.

It uses the same basic formula that is used for cancelling emails except it uses the cancelsms command:

after pagename if cancelsms ("unique name for email", e-mail address) goto nextpage

changepassword

This command enables users to change their password. The formula for using this command would be:

after pagename1 if changepassword (username, pagename1.name_of_interaction_for_entering_old_password, pagename1.name_of_interaction_for_entering_new_password) goto pagename2

Example

after passworddetails if changepassword (username, passworddetails.old, passworddetails.new) goto confirmchange




checkemailvalidity

Checks that the e-mail that a user has entered is valid (i.e. contains an @ symbol).

checkphonenumbervalidity

checkuserenabled

checkuserexists

comparetimes

contains

countif

currenttime

divide

hasseen

hasseen is used to show end-users pages based on what they have or have not seen before.

Example 1

If you wanted to show end-users a different page each time they logged in depending on what sessions they had seen before you may use the hasseen command like so:

show login

show s1welcome if (not(hasseen (username, "s1welcome"))) show s2welcome if (not(hasseen (username, "s2welcome"))) show s3welcome if (not(hasseen (usernme, "s3welcome")))

This would mean that the first time they login they would see the session 1 welcome page which is labelled s1welcome. The next time they log in, because they have already seen the s1welcome page the logic will skip that line of logic and show them s2welcome because they have not yet seen the s2welcome page.

isempty

or

lessthan

This command can be used when performing calculations in the logic to check if one value is lower than another. The symbol < can also be used.

lessthanequal

This command can be used when performing calculations in the logic to check if one value is lower than or equal to another. The symbol <= can also be used.

loadvalue

makenewuser

The makenewuser is very important; it is used to set up an account for the user using a username (or e-mail address) and password.

Example

show signup

after signup if (makenewuser(signup.signup_username, signup.signup_password)) goto thankyou

So in the example above the information that the end-user enters into the interactions 'signup_username' and 'signup_password' is used to create a user account.

morethan

morethanequal

multiply

not

patternmatch

printtime

The printtime converts a value from a number to a string

randomnumber

This command allows you to randomise your users into different groups.

replaceall

This command can be used to do text replacements inside a string.

Example

In the following example the replaceall command is used to replace all the 'a's in a string to 'b's. So this would change 'I like apples a lot' to 'I like bpples b lot'

replaceall ("a", "b", "I like apples a lot")

resetpassword

savevalue

sendemail

sendtext

size

stringlength

sum

timesincelogin