Roles

Interviews with multiple users

docassemble allows you to create multi-user interviews.

For example:

  • In a legal application, a client uses the interview to answer questions about the facts of a case, and then an attorney reviews the responses, answers questions about how the law applies to the facts, and then the client comes back to the interview to receive a legal advice letter.
  • If a user’s language is not English, a translator will be invited to join the interview to translate the user’s textual responses into English before the interview process is completed.
  • Two parties who are negotiating with one another will fill in answers to an interview, and when both are done, the interview will suggest a resolution based on the answers of both parties.

Multi-user interviews are implemented through the user login feature and three authoring features that were introduced in other sections:

  • role modifier: designates certain questions as being answerable only by a particular user (or group of users).
  • default role initial block: sets the role modifier for questions that do not have a role explicitly set. The code within this block is run as initial code. The responsibility of this code is to set the special variable role depending on the circumstances, which can include the identity and privileges of the person logged in, which can be retrieved with the functions user_logged_in(), user_info(), user_privileges(), and user_has_privilege().
  • event variables: when the current user cannot proceed further with the interview because the interview needs input from a different user, docassemble will display a message for the current user. It finds this message by looking for a question marked with event: role_event. Mako template commands can be used in this question to say different things depending on who the current user is and who the new user needs to be.

The following example of a three-role interview demonstrates how multi-user interviews are created in docassemble.

The interview starts with an organizer, who clicks past an introductory screen and is asked for the e-mail addresses of two participants who will bid on a contract. The organizer is then asked to invite the participants to bid by clicking on a particular link and logging in. Once both bidders have entered their bids, the winner (the participant with the lowest bid) is announced. Until both participants have entered bids, users will see a page telling them to wait and to press the “Check” button to see if both bids have been made yet (except for bidders who haven’t bid yet, who will be asked for their bids).

---
modules:
  - docassemble.base.util
---
default role: organizer
code: |
  multi_user = True
  role = 'organizer'
  if introduction_made and participants_invited:
    if user_logged_in():
      if user_info().email == first_person_email:
        role = 'first_person'
      elif user_info().email == second_person_email:
        role = 'second_person'
---
event: role_event
question: Waiting on another participant
subquestion: |
  % if 'first_person' in role_needed or 'second_person' in role_needed:
  We are waiting for a participant to put in a bid.
  % else:
  We are waiting for the organizer.
  % endif

  % if not user_logged_in():
  If you were invited to participate, please click "Sign in."
  % endif

  Press **Check** to check on the status.
buttons:
  - Check: refresh
---
mandatory: True
code: |
  if role == 'first_person':
    first_person_bid
  if role == 'second_person':
    second_person_bid
  announce_winner
---
field: introduction_made
question: |
  Welcome to a test of the multi-user system!
subquestion:
  This is the start of a test of the multi-user system.
  You are the organizer.  To continue, press **Continue**.
---
code: |
  if first_person_email == second_person_email:
    organizer_messed_up
  else:
    recipients_ok = True
---
field: participants_invited
need: recipients_ok
question: |
  Invite the bidders
subquestion: |
  Ok, organizer, send e-mails to ${ first_person_email } and
  ${ second_person_email } inviting them to submit bids.

  Tell them to go to the following URL:

  [${ interview_url() }](${ interview_url() })
---
sets: announce_winner
role:
  - organizer
  - first_person
  - second_person
question: And the winner is...
subquestion: |
  % if first_person_bid < second_person_bid:
  The winning bidder is First Person!
  % elif first_person_bid > second_person_bid:
  The winning bidder is Second Person!
  % else:
  Sorry, no winner.  The bids matched.
  % endif
---
question: |
  What are the e-mail addresses of the participating bidders?
fields:
  - First Person: first_person_email
    datatype: email
  - Second Person: second_person_email
    datatype: email
---
role: first_person
question: |
  How much will you bid for the contract?
fields:
  - Amount: first_person_bid
    datatype: currency
---
role: second_person
question: |
  How much will you bid for the contract?
fields:
  - Amount: second_person_bid
    datatype: currency
---
sets: organizer_messed_up
question: |
  That won't work.
subquestion: |
  Please try again.  This time enter different e-mail addresses
  for the participants.
buttons:
  - Restart: restart
...

Most of the code is self-explanatory, but a few of the blocks warrant explanation.

Consider the second block:

---
default role: organizer
code: |
  multi_user = True
  role = 'organizer'
  if introduction_made and participants_invited:
    if user_logged_in():
      if user_info().email == first_person_email:
        role = 'first_person'
      elif user_info().email == second_person_email:
        role = 'second_person'
---

Here, we set the default role to organizer. This simply means that questions in the interview that do not have a role specified will require the organizer role.

The code is initial code, the primary purpose of which is to set the role variable, which is the role of whichever user is currently in the interview. This code runs every single time the page loads for any user.

This code block also sets the special variable multi_user to True, which tells docassemble that multiple users will be using this interview. When multi_user is True, docassemble will not encrypt the answers on the server. This reduces security somewhat, but is necessary in order for multiple users to participate in the same interview.

First, note that the role for all users will remain organizer until the organizer has seen the introductory page and the participants have been invited.

Second, note that the flow of the interview is being controlled here. The references to introduction_made and participants invited mean that questions will be asked to define those variables if they are undefined. This is the code that causes those questions to appear for the organizer. After the role is set, the mandatory code block controls the flow of the interview.

Third, note that by requiring participants invited to be set before we consider whether the user’s e-mail address is equal to first_person_email, we ensure that the interview flow proceeds the way we want it to. Suppose we did not check for participants invited before doing this. If the organizer was logged in and gave his own e-mail address as that of a participant, he would assume the role of a participant before learning the URL that he needs to give to the other participant.

There are times when you just want docassemble to figure out the interview flow implicitly, and there are times when you want to be explicit about it. Setting up roles is one situation where you want to be pretty explicit, so that users do not see role_event screens unnecessarily.

Another block that warrants explanation is the mandatory code block:

---
mandatory: True
code: |
  if role == 'first_person':
    first_person_bid
  if role == 'second_person':
    second_person_bid
  announce_winner
---

This code block sets a goal for the interview: finding the value of announce_winner. Note that if we took out the two if statements, the interview could still get done, because announce_winner implicitly asks for both firth_person_bid and second_person_bid. The problem with that (or the inconvenience) is that announce_winner looks for the value of first_person_bid before it looks for the value of second_person_bid. This means that the second participant would have to wait to enter his bid until the first participant had done so. This would be arbitrary and could cause unnecessary delay. The additional code here will ask each participant for his bid regardless of which one is first to log in.

The URL that is created through interview_url() contains the secret “session key” of the interview, which was created when the organizer started the interview. When someone goes to this URL, they will enter the interview that is already in progress, whatever the current state of the interview is. Note that the URL in the location bar of the web browser will be shortened after the first page load, but the interview-specific information in the URL will not be forgotten (essentially, it is moved from the location bar into a cookie in the web browser).

Interviews with an unknown number of users

In the example above, there were two participants in the interview (other than the organizer): first_person and second_person. But what if you will have more than two participants? Do you have to create roles up to ten_thousandth_person? No – there are other ways to handle multi-user interviews.

Consider the following example, which uses generic objects:

---
modules:
  - docassemble.base.util
---
objects:
  - respondents: DADict
---
initial: True
code: |
  multi_user = True
  if user_logged_in():
    if user_info().email not in respondents:
      respondents.initializeObject(user_info().email)
    user = respondents[user_info().email]
    final_page
  else:
    must_be_logged_in_page
---
sets: final_page
question: |
  <%
    cat_count = 0
    for email in respondents:
      respondent = respondents[email]
      if respondent is user or hasattr(respondent, 'number_of_cats'):
        cat_count += respondent.number_of_cats
  %>
        
  % if cat_count == 0:
  There are zero cats so far.
  % elif cat_count == 1:
  There is only one cat so far.
  % else:
  There are ${ cat_count } cats in all.
  % endif
subquestion: |
  Share this link with others!

  [${ interview_url() }](${ interview_url() })
buttons:
  - Check: refresh
---
generic object: DAObject
question: How many cats do you have?
fields:
  - Number of cats: x.number_of_cats
    datatype: integer
---
sets: must_be_logged_in_page
question: Please log in
subquestion: |
  Please click "Sign in" to continue.  If you do not have
  an account, you can register for one.
buttons:
  - Sign in: signin
...

This interview asks every user how many cats he or she has, and then tells the user the total number of cats of all of the interview respondents.

Note that this interview allows multiple users but does not make use of the role and default role features. The purpose of those features is to put one user on hold while waiting for input from another user. There are some situations, like the above interview, that do not require one user to wait for another user. In that case, it is not necessary to set user roles.

The initial code block makes sure that the user is logged in, and sets the user variable to a DAObject.

A DAObject is the most basic type of docassemble object. Its definition is in [docassemble.base.util]. The fact that the user is a DAObject means that the user can have attributes and those attributes can be gathered with generic object questions.

The initial code block also keeps track of all the users that have used the interview (i.e. by either starting the interview from scratch or clicking on the link given by interview_url) so that the Mako code in the final_page question can loop over all of the users and tally up the number of cats.

These lines in the initial block define the user variable and keep track of each user:

if user_info().email not in respondents:
  respondents.initializeObject(user_info().email)
user = respondents[user_info().email]

user_info() is a special function that returns information about the logged-in user. If the user was not logged in, the email would not be known. The email is a unique identifier for each user in the login system.

The objects block defines respondents as an object of type DADict. A DADict acts much like an ordinary Python dictionary, except that it has special properties that allow docassemble to set its attributes using generic object questions.

The second line in the excerpt above defines an entry in this Python dictionary, respondents[user_info().email] as a new object of type DAObject. The initializeObject() method effectively does this:

respondents[user_info().email] = DAObject()

However, it does not work to actually write that; the initializeObject() method takes care of the docassemble internals that allow docassemble to set undefined attributes.

Note that the modules block is necessary in this interview; otherwise we could not refer to names like DAObject and DADict.

The Mako code contains this line:

if respondent is user or hasattr(respondent, 'number_of_cats'):
  cat_count += respondent.number_of_cats

The hasattr function is a built-in Python function that returns True if respondent has an attribute called number_of_cats, and False if not. We are saying here that we want to tally the total number of cats for the user and all respondents who have answered the question about the number of cats they have. If we did not exclude respondents who had not yet indicated their number of cats, then the user might be asked for the number of cats belonging to a different respondent. It would be rare that this would ever happen – it would happen if the user checked the number of cats between the time another respondent logged in and the time the respondent entered his number of his cats – but it is important to anticipate and control for rare cases.

A two-user interview that does not use the roles system

You do not need need to use the role-switching system to have a multi-user interview. It helps, though, to use the user login system to keep track of who the user is. Here is an example of an interview where two users each sign a document:

modules:
  - docassemble.base.util
---
objects:
  firstparty: Individual
  secondparty: Individual
---
initial: true
code: |
  multi_user = True
  if user_logged_in():
    if not defined('firstparty.email'):
      firstparty.email = user_info().email
    if user_info().email == firstparty.email:
      firstparty.endpoint      
    elif user_info().email == secondparty.email:
      secondparty.endpoint
    else:
      user_kicked_out
  else:
    user_must_log_in
---
event: firstparty.endpoint
code: |
  firstparty.name.first
  secondparty.name.first
  firstparty.thing
  firstparty.signature
  if not defined('secondparty.signature'):
    waiting_on_second_party
  final_screen
---
event: secondparty.endpoint
code: |
  secondparty.consents
  secondparty.signature
  final_screen
---
question: |
  What is your name?
fields:
  - First Name: firstparty.name.first
  - Last Name: firstparty.name.last
---
question: |
  What is the name and e-mail address
  of the other party to the contract?
fields:
  - First Name: secondparty.name.first
  - Last Name: secondparty.name.last
  - E-mail: secondparty.email
    datatype: email
---
question: |
  If you agree to convey
  ${ secondparty.thing }
  to ${ firstparty },
  press Continue.
field: secondparty.consents
---
generic object: Individual
question: |
  What is your least valuable possession?
fields:
  - no label: x.thing
---
generic object: Individual
question: |
  Please sign your name below.
signature: x.signature
under: |
  ${ x.name }
---
event: user_must_log_in
question: |
  In order to use this interview,
  you need to log in.
subquestion: |
  If you have not yet created an
  account, press register.
buttons:
  Register: register
  Log in: signin
prevent going back: True
---
event: user_kicked_out
question: |
  You are not authorized.
subquestion: |
  I'm not sure how you got here,
  but you do not belong.  Scram!
---
event: waiting_on_second_party
question: |
  Done for now.
subquestion: |
  Please ask ${ secondparty } to go to
  [this link](${ interview_url() })
  and register with the e-mail
  address ${ secondparty.email }.

  After ${ secondparty } has done this,
  you can come back to this interview
  (using the
  [same link](${ interview_url() }))
  and retrieve the signed agreement.
---
event: final_screen
question: |
  Here is the signed contract.
attachment:
  name: |
    An agreement between
    ${ firstparty } and
    ${ secondparty }
  filename: agreement
  docx template file: Agreement_To_Transfer.docx
multi-user