Creating Method to call in Visualforce Page

Question

I'm having some difficulty creating a method to call in a VF page. I believe I should be doing this by creating an Apex Class as a controller extension, but please correct me if I'm wrong and help me understand where I can create a method. I think SalesForce doesn't always do well with covering the very basics.

Here is what I currently have in a new Apex Class, but I'm getting errors on the variables, although, I believe I'm accessing the Intake controller, where these variables exist, so I'm not sure.

public with sharing class ShouldShowSHSection {
    public ApexPages.StandardController Intake {get; set;}
    public Boolean getShouldShowSHSection() {
  if(
    record.Personal_Care__c.contains('Toileting/Bathing/Self-Care in Bathroom') && !record.Physical_Concerns__c.contains('Controlling Environment with Limited Mobility (turning on lights/opening doors)')
    ) 
    {
    return true;
    }

  if(
    record.Personal_Care__c.contains('Sleeping Routines/Up and About at Night') && !record.Physical_Concerns__c.contains('Controlling Environment with Limited Mobility (turning on lights/opening doors)')
    )  
    {
    return true;
    }

    if(
    record.Personal_Care__c.contains('Completing Daily Living Routines with Auditory Prompts like Laundry/Cooking/Cleaning') && !record.Physical_Concerns__c.contains('Controlling Environment with Limited Mobility (turning on lights/opening doors)')
    )  
    {
    return true;
    }
  
  if(
    record.Safety_Concerns__c.contains('Cooking Safety/Meal Prep') && !record.Physical_Concerns__c.contains('Controlling Environment with Limited Mobility (turning on lights/opening doors)')
    )  
    {
    return true;
    }

  if(
    record.Social_Concerns__c.contains('Having Privacy or Being Alone Part or All of Day or Night') && !record.Physical_Concerns__c.contains('Controlling Environment with Limited Mobility (turning on lights/opening doors)')
    )  
    {
    return true;
    }

    if(
    record.Social_Concerns__c.contains('Using Tech for Social Connection with Friends and Family') && !record.Physical_Concerns__c.contains('Controlling Environment with Limited Mobility (turning on lights/opening doors)')
    )  
    {
    return true;
    }


    if(
    record.Social_Concerns__c.contains('Using Tech for Entertainment (smart speakers/social media)') && !record.Physical_Concerns__c.contains('Controlling Environment with Limited Mobility (turning on lights/opening doors)')
    )  
    {
    return true;
    }


    if(
    record.Safety_Concerns__c.contains('Using Tech for Entertainment (smart speakers/social media)') && (
    !record.Physical_Concerns__c.contains('Controlling Environment with Limited Mobility (turning on lights/opening doors)') ||
    record.Personal_Care__c.contains('Toileting/Bathing/Self-Care in Bathroom') ||
    record.Personal_Care__c.contains('Sleeping Routines/Up and About at Night') ||
    record.Personal_Care__c.contains('Completing Daily Living Routines with Auditory Prompts like Laundry/Cooking/Cleaning') ||
    record.Safety_Concerns__c.contains('Cooking Safety/Meal Prep') ||
    record.Social_Concerns__c.contains('Having Privacy or Being Alone Part or All of Day or Night') ||
    record.Social_Concerns__c.contains('Using Tech for Social Connection with Friends and Family') ||
    record.Social_Concerns__c.contains('Using Tech for Entertainment (smart speakers/social media)') ||
    record.Physical_Concerns__c.contains('Getting in or Out of Bed or Chair')
    )
    )  
    {
    return true;
    }


    if(
    record.Safety_Concerns__c.contains('Wandering or Elopement/Running Way or Egress (Leaving the Home)') && (
    !record.Physical_Concerns__c.contains('Controlling Environment with Limited Mobility (turning on lights/opening doors)') ||
    record.Personal_Care__c.contains('Toileting/Bathing/Self-Care in Bathroom') ||
    record.Personal_Care__c.contains('Sleeping Routines/Up and About at Night') ||
    record.Personal_Care__c.contains('Completing Daily Living Routines with Auditory Prompts like Laundry/Cooking/Cleaning') ||
    record.Safety_Concerns__c.contains('Cooking Safety/Meal Prep') ||
    record.Social_Concerns__c.contains('Having Privacy or Being Alone Part or All of Day or Night') ||
    record.Social_Concerns__c.contains('Using Tech for Social Connection with Friends and Family') ||
    record.Social_Concerns__c.contains('Using Tech for Entertainment (smart speakers/social media)') ||
    record.Physical_Concerns__c.contains('Getting in or Out of Bed or Chair')
    )
    )  
    {
    return true;
    }

    if(
    record.Safety_Concerns__c.contains('Confusion or Dementia') && (
    !record.Physical_Concerns__c.contains('Controlling Environment with Limited Mobility (turning on lights/opening doors)') ||
    record.Personal_Care__c.contains('Toileting/Bathing/Self-Care in Bathroom') ||
    record.Personal_Care__c.contains('Sleeping Routines/Up and About at Night') ||
    record.Personal_Care__c.contains('Completing Daily Living Routines with Auditory Prompts like Laundry/Cooking/Cleaning') ||
    record.Safety_Concerns__c.contains('Cooking Safety/Meal Prep') ||
    record.Social_Concerns__c.contains('Having Privacy or Being Alone Part or All of Day or Night') ||
    record.Social_Concerns__c.contains('Using Tech for Social Connection with Friends and Family') ||
    record.Social_Concerns__c.contains('Using Tech for Entertainment (smart speakers/social media)') ||
    record.Physical_Concerns__c.contains('Getting in or Out of Bed or Chair')
    )
    )  
    {
    return true;
    }

    if(
    record.Safety_Concerns__c.contains('Accessing Help for an Emergency') && (
    !record.Physical_Concerns__c.contains('Controlling Environment with Limited Mobility (turning on lights/opening doors)') ||
    record.Personal_Care__c.contains('Toileting/Bathing/Self-Care in Bathroom') ||
    record.Personal_Care__c.contains('Sleeping Routines/Up and About at Night') ||
    record.Personal_Care__c.contains('Completing Daily Living Routines with Auditory Prompts like Laundry/Cooking/Cleaning') ||
    record.Safety_Concerns__c.contains('Cooking Safety/Meal Prep') ||
    record.Social_Concerns__c.contains('Having Privacy or Being Alone Part or All of Day or Night') ||
    record.Social_Concerns__c.contains('Using Tech for Social Connection with Friends and Family') ||
    record.Social_Concerns__c.contains('Using Tech for Entertainment (smart speakers/social media)') ||
    record.Physical_Concerns__c.contains('Getting in or Out of Bed or Chair')
    )
    )  
    {
    return true;
    }

    if(
    record.Physical_Concerns__c.contains('Walking or Mobility') && (
    !record.Physical_Concerns__c.contains('Controlling Environment with Limited Mobility (turning on lights/opening doors)') ||
    record.Personal_Care__c.contains('Toileting/Bathing/Self-Care in Bathroom') ||
    record.Personal_Care__c.contains('Sleeping Routines/Up and About at Night') ||
    record.Personal_Care__c.contains('Completing Daily Living Routines with Auditory Prompts like Laundry/Cooking/Cleaning') ||
    record.Safety_Concerns__c.contains('Cooking Safety/Meal Prep') ||
    record.Social_Concerns__c.contains('Having Privacy or Being Alone Part or All of Day or Night') ||
    record.Social_Concerns__c.contains('Using Tech for Social Connection with Friends and Family') ||
    record.Social_Concerns__c.contains('Using Tech for Entertainment (smart speakers/social media)') ||
    record.Physical_Concerns__c.contains('Getting in or Out of Bed or Chair')
    )
    )  
    {
    return true;
    }

    if(
    record.Physical_Concerns__c.contains('Getting in or Out of Bed or Chair') && (
    !record.Physical_Concerns__c.contains('Controlling Environment with Limited Mobility (turning on lights/opening doors)') ||
    record.Personal_Care__c.contains('Toileting/Bathing/Self-Care in Bathroom') ||
    record.Personal_Care__c.contains('Sleeping Routines/Up and About at Night') ||
    record.Personal_Care__c.contains('Completing Daily Living Routines with Auditory Prompts like Laundry/Cooking/Cleaning') ||
    record.Safety_Concerns__c.contains('Cooking Safety/Meal Prep') ||
    record.Social_Concerns__c.contains('Having Privacy or Being Alone Part or All of Day or Night') ||
    record.Social_Concerns__c.contains('Using Tech for Social Connection with Friends and Family') ||
    record.Social_Concerns__c.contains('Using Tech for Entertainment (smart speakers/social media)') ||
    record.Physical_Concerns__c.contains('Getting in or Out of Bed or Chair')
    )
    )  
    {
    return true;
    }

  return false;
}

}

My VisualForce Page will be calling this like this:

<apex:pageBlockSection rendered="{!shouldShowSHSection}">

Answer 1

You don't need to create a method to access data in Visualforce; you need to expose a property. You've really already done this, because Visualforce understands a method named getShouldShowSHSection() to be the "getter" for a property named shouldSHowSHSection, which you can access in a Visualforce expression. Note that this is largely equivalent to the get/set style getters and setters that you can also use.

The problem here is that the variable record does not exist. You'd need to access it by doing this.Intake.getRecord() to ask the standard controller for it.

Note that you have to ensure that the standard controller queries all of the fields you wish to use when it acquires record data. The easiest way to do so is to reference the field in your page's markup; if you do not reference the fields you are using here in markup, you would need to call the standard controller's addFields() method on the standard controller instance when you receive it in your extension class's controller.

Edit

Your Apex and Visualforce are correct, saving only that you are referencing an undefined record variable in Apex. You have to assign it via Intake__c record = (Intake__c)this.Intake.getRecord().

Also bear in mind the note above about field access, though; if you get an error about a field not being retrieved via SOQL, that's the problem.