Solara•2mo ago

Creating a form when I don't know how many user inputs there will be at development time

message.txt

3 Replies

Brian•2mo ago

Sorry for the bad formatting... Discord won't let me paste text without adding it as an attachment. I want to create a form that has a few questions for a user to answer. I want to store the questions in a database, which means that the application won't know ahead of time how many questions there will be. So let's say a have a table like:

| question_id | question_text                |
|-------------|------------------------------|
| 1           | What is your name?           |
| 2           | What is your quest?          |
| 3           | What is your favorite color? |

| question_id | question_text                |
|-------------|------------------------------|
| 1           | What is your name?           |
| 2           | What is your quest?          |
| 3           | What is your favorite color? |

On application start, I would expect to read these questions into a dictionary {question_id: question_text}. When constructing my form (using solara.lab.ConfirmationDialog), I would loop through the list of questions to create a prompt (solara.Text) and an input text box (solara.InputText). When the user submits the form, I want to capture the responses and write them to a table in my database like:

| submission_id | answer_id | question_id | answer_text           |
|---------------|-----------|-------------|-----------------------|
| 1             | 1         | 1           | Sir Lancelot          |
| 1             | 2         | 2           | I seek the Holy Grail |
| 1             | 3         | 3           | Blue                  |
| 2             | 4         | 1           | Sir Galahad           |
| 2             | 5         | 2           | I seek the Grail      |
| 2             | 6         | 3           | Blue...               |

| submission_id | answer_id | question_id | answer_text           |
|---------------|-----------|-------------|-----------------------|
| 1             | 1         | 1           | Sir Lancelot          |
| 1             | 2         | 2           | I seek the Holy Grail |
| 1             | 3         | 3           | Blue                  |
| 2             | 4         | 1           | Sir Galahad           |
| 2             | 5         | 2           | I seek the Grail      |
| 2             | 6         | 3           | Blue...               |

My issue/question is: how do I create the reactive variable(s) to capture the user input? I would expect that the value that I want to pass to the InputText should be a reactive variable (?), or else that I would create a reactive variable that is a dictionary and have it be keyed by question_id with the values being the text in the InputText. I've tried creating a dict of reactive variables and a reactive dict, but it doesn't seem to work. Here is a minimal example. It "works," except that when you click "Answer" nothing happens -- the print statements do not execute.

import pandas as pd
import solara

# assume that we have a table in a database, and
# we read the data into _something_ like this:
#
question_table = pd.DataFrame(
    data=[
        [1, "What is your name?"],
        [2, "What is your quest?"],
        [3, "What is your favorite color?"]
    ],
    columns=["question_id", "question_text"]
)

# or else it can be treated like a list of dicts
#
questions = question_table.to_dict(orient="records")
# questions
# [{'question_id': 1, 'question_text': 'What is your name?'},
#  {'question_id': 2, 'question_text': 'What is your quest?'},
#  {'question_id': 3, 'question_text': 'What is your favorite color?'}]

import pandas as pd
import solara

# assume that we have a table in a database, and
# we read the data into _something_ like this:
#
question_table = pd.DataFrame(
    data=[
        [1, "What is your name?"],
        [2, "What is your quest?"],
        [3, "What is your favorite color?"]
    ],
    columns=["question_id", "question_text"]
)

# or else it can be treated like a list of dicts
#
questions = question_table.to_dict(orient="records")
# questions
# [{'question_id': 1, 'question_text': 'What is your name?'},
#  {'question_id': 2, 'question_text': 'What is your quest?'},
#  {'question_id': 3, 'question_text': 'What is your favorite color?'}]

@solara.component
def BridgeOfDeath(is_open, on_ok, questions):
    # normally, I would create some reactive variables here, but I don't know
    # how many (apart from `len(questions)`). I also need to associate those
    # reactive variables with to the question IDs so that I can save the data.

    # Should it be a reactive dict, like:
    # answers_by_question_id = solara.use_reactive({})

    # Or a dict of reactive variables like:
    answers_by_question_id = {
        question["question_id"]: solara.use_reactive("")
        for question in questions
    }

    def _on_ok():
        print("_on_ok called")
        on_ok(answers_by_question_id)
    
    with solara.lab.ConfirmationDialog(
        is_open,
        ok=solara.Button(
            label="Answer",
            on_click=_on_ok,
            # disabled=  # if any question is unanswered
        ),
        on_ok=_on_ok,
        title="Answer",
        max_width=1000,
    ):
        
        for question in questions:
            question_id = question["question_id"]
            question_text = question["question_text"]
            
            with solara.Card():
                solara.Text(question_text)
                solara.v.Spacer()
                solara.InputText(
                    label=f"Question #{question_id}",
                    value=answers_by_question_id[question_id].value,
                    on_value=answers_by_question_id[question_id].set,
                    continuous_update=True,
                )

@solara.component
def BridgeOfDeath(is_open, on_ok, questions):
    # normally, I would create some reactive variables here, but I don't know
    # how many (apart from `len(questions)`). I also need to associate those
    # reactive variables with to the question IDs so that I can save the data.

    # Should it be a reactive dict, like:
    # answers_by_question_id = solara.use_reactive({})

    # Or a dict of reactive variables like:
    answers_by_question_id = {
        question["question_id"]: solara.use_reactive("")
        for question in questions
    }

    def _on_ok():
        print("_on_ok called")
        on_ok(answers_by_question_id)
    
    with solara.lab.ConfirmationDialog(
        is_open,
        ok=solara.Button(
            label="Answer",
            on_click=_on_ok,
            # disabled=  # if any question is unanswered
        ),
        on_ok=_on_ok,
        title="Answer",
        max_width=1000,
    ):
        
        for question in questions:
            question_id = question["question_id"]
            question_text = question["question_text"]
            
            with solara.Card():
                solara.Text(question_text)
                solara.v.Spacer()
                solara.InputText(
                    label=f"Question #{question_id}",
                    value=answers_by_question_id[question_id].value,
                    on_value=answers_by_question_id[question_id].set,
                    continuous_update=True,
                )

@solara.component
def Page():
    def save_answers(answers):
        print(f"Method to save answers to the database: {answers}")
    
    bridge_of_death_is_open = solara.use_reactive(False)

    with solara.Card(
        "Who would cross the Bridge of Death must answer me "
        "these questions three, ere the other side ye see:"
    ):
        BridgeOfDeath(
            bridge_of_death_is_open,
            on_ok=save_answers,
            questions=questions,
        )
    
        solara.Button(
            label="Ask me the questions, I am not afraid.",
            on_click=lambda: bridge_of_death_is_open.set(True),
        )

Page()

@solara.component
def Page():
    def save_answers(answers):
        print(f"Method to save answers to the database: {answers}")
    
    bridge_of_death_is_open = solara.use_reactive(False)

    with solara.Card(
        "Who would cross the Bridge of Death must answer me "
        "these questions three, ere the other side ye see:"
    ):
        BridgeOfDeath(
            bridge_of_death_is_open,
            on_ok=save_answers,
            questions=questions,
        )
    
        solara.Button(
            label="Ask me the questions, I am not afraid.",
            on_click=lambda: bridge_of_death_is_open.set(True),
        )

Page()

rob-vh•2mo ago

Here is an example of a table driven editor, using a dataframe. https://py.cafe/rob.on.lists/solara-inventory-tracker-using_dummy_reactive To display the updates to the df, I use a reactive that I just increment. I could also have stored the whole dict in the reactive, but then updates (!) to the dict are not taken as changes, unless I first overwrite the reactive with None. https://py.cafe/rob.on.lists/solara-inventory-editor-only-works-first-time I believe is issue is here https://github.com/widgetti/solara/issues/245

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GitHub

Event not firing when reactive variable is set · Issue #245 · widge...

I'm trying to create a solara=1.19.0 component in jupyterlab=4.0.5 with ipywidgets=8.1.0 (on Windows) I have from_date = sol.use_reactive(cast(Optional[str], None)) which will be set to (a stri...

Brian•2mo ago

Thank you for this example -- I was able to get it working by following what you did. Very helpful!

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Creating a form when I don't know how many user inputs there will be at development time