I have a requirement to perform a callout, get response (byte array) that is a PDF base 64 encoded. Then, i need to show the pdf, without saving any data in Salesforce. I just need to view the response in PDF.
So, is there a way to achieve this?
What i have done is:
I have created an LWC to perform the callout on rowaction of a Lightning data table. So onRowAction a JS function is called which calls Apex. Apex performs the callout, gets response and then i need to render the result in PDF. I have tried opening a Visualforce page (calling it either from JS Controller of LWC or from Apex, but i could not find solution... I could not pass my parameter to the page so the PDF was always blank. 
Please find below a high level diagram of the problem that i am facing and what i want to do..


Any suggestions??

I have a flow where it has:

1. Screen flow consisting of some inputs (text, picklist, etc...)
2. Assignment to a new lead record variable (All input values are assigned to the respective fields of the lead)
3. Apex Action to perform some validations and return the valid lead (e.g. validate text fields do not consist of mixed greek and latin characters and also capitalize characters etc)
4. Condition (If apex returns that we have a validation error (mixed characters), i want to navigate to the first screen, and also update the screen elements with the capitalized characters.

My problem is, i cannot find a way to assign the capitalized characters to the screen elements. For example, if the user input on FirstName field is 'Giorgos', apex will return 'GIORGOS'. This will also update my lead record returned, however i want also to update the screen Element from 'Giorgos' to "GIORGOS". How can this be achieved?

I have a flow to create a lead record. I have several fields, some of them are picklists where i have 2 choices, one choice for --None--, and another choice with the values of this field. For example, like the picture below:


In my flow, the steps are the following:
Screen -> New Lead (provides all the necessary fields to the user in order to fill them in)
Assignment -> Assign all the values inserted by the user to a Lead Record
Call apex function where this lead record is given as input and perform a custom validation
In case of validation error, return back to the initial screen but the values need to be as filled in by the user.

Problem: When navigating back to the initial screen, all the values of picklist fields are returned to the --none-- choice, however i want to keep the previous one selected by the user.
I don't want to have all the choices separately, since they may change often, so i want to get all the picklist values dynamically.
I want this flow to be able to be functional on partner communities.
How could i resolve this issue? Any suggestions ?

I need to override standard Create and Edit Actions on Account object with Lightning Component. Is there a way or a type of field that we could cover the following requirement? Have a field with some predifined values but letting user if he wants to enter free text. I would actually like something like Subject field on Task object but i cannot find any way to implement it. Any ideas please ?
Example: I have a picklist field for Citizenship that has some values for Countries (England, Germany, France, ...etc...). But i want to let user enter his own value (for example: German). i have tried using the following but without success:
 

<!--05/09/2019 George Galaios: Code for Iteration Picklist: Citizenship -->
                        <lightning:select aura:id="accCitizenship" label="{!$Label.c.ea_citizenship}" value="{!v.accountRecord.ea_Citizenship__c}" disabled="{!and(v.noExtraPermission, v.noPermAndCleansed)}" class="slds-size--1-of-2 slds-p-horizontal_x-small">
                            <aura:iteration items="{!v.ea_Citizenship_Values}" var="item">
                                <option value="{!item}" selected="{!item==v.accountRecord.ea_Citizenship__c}">{!item}</option>
                            </aura:iteration>
                        </lightning:select>                
                        <!-- End of Code for Iteration -->