Making Session Variables Work in .NET Core

The Problem

As noted, I work with Legacy and often have to bring in variables from the API that must be sustained across session.. (and I’m sure there might be a better way, comment and advise!).  Where I am at now, is I query the API and bring in the variables, but how do I keep from calling these over and over?  The old solution was session variables and so, that’s where I am at.

When I started to do this on Core, the most helpful article was this (and it’s in my comments):

https://adamstorr.azurewebsites.net/blog/are-you-registering-ihttpcontextaccessor-correctly

He leads you through the basic setup of a HttpContext helper class (that I still use today) and how to configure the startup..  Today, though, I came across a problem: I was able to Set session variables, but the Get was pulling null.

The Reason

Order.  Yes, you’ll see 1000 stackflow responses about order in Configure (and I was careful to do this in that method), but now in ConfigureServices (contrary to the example, as I am now using Core 2.2?), order again comes into play:

public void ConfigureServices(IServiceCollection services)
{
    //this MUST be before add mvc or session returns null
    services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
    services.AddMvc();

First Heroku App: Small API in PHP to Talk to .Net Core

I’ve recently been curious about switching to a time API for my time stamps and removing any dependency the app might have on the server for a timestamp.  Upon Googling I found some paid services, some free and of the free ones, I noticed one was hosted on Heroku.  I’ve heard of Heroku, but never had a reason to attempt to use it.  This was the perfect chance.

How I Created a Small “GetTime” API

First, I created a free account on Heroku, nothing special.  After verifying my email, I logged in to my Heroku Dashboard and up on the right hand corner, selected Create New App.  I named it my company-api and out popped an app.

I decided on just plain, legacy PHP and a simple DateTime string passed thru JSON encode, just to get started.  No authentication, no timezone,  just a simple spit out if a request to the site came, like this:

<?php
    header('Content-type:application/json;charset=utf-8');

    $DateTime = new DateTime();
    $currentTime = $DateTime->format("Y-m-d H:i:s");
    echo json_encode($currentTime);
?>

I created a Git repo for this brand new file and pushed it out.  Then, I went back to Heroku, Dashboard, My App and Deploy.  I selected Github as my deploy “resource” …

Share Azure Blobs with Search and Tree View

The idea behind this was to create a nice, easy UI that users can download media files they request often.  We moved it to Azure to prevent killing our on-prem bandwidth, but then I had to deal with the flat file structure, etc.  The end result was simply: a fast search of all the blobs (with link) and underneath that, a tree structure of the blobs that they can browse through.

The Set Up

First, I created a Storage container through Azure Portal, then I used Azure Storage Explorer to create a Blob Container under that storage account.  I also set read-only permissions to my blobs by right clicking the container in Azure Storage Explorer, then: Set Container Public Access Level > Public Read Access for Blobs Only.

To make this code work, I needed to setup an environment variable for my connection string.  I used the prefix CUSTOMCONNSTR_ on my variable name as it comes in handy when deploying to Azure Web Apps.  To get the connection string:  Azure Portal > Storage Account you created > Access Keys.

setx CUSTOMCONNSTR_storageConnectionString "<yourconnectionstring>"

Finally, I got a folder I wanted to share and dragged and dropped it into my …

Using Libman Providers to Coral Front End Libraries

The first package management system I learned to use was Bower.  It was great for the short love affair we had together, but it stopped being supported and I was weary of learning to use one of its replacements.  Fortunately, I haven’t had to with Libman.  Libman’s (Library Manager) simple JSON approach to bringing front end dependencies has been the easiest for me quickly implement and it has been a great addition to Visual Studio.  I implemented it possibly too quickly, however, and overlooked one powerful configuration setting:  provider.

.Net Core – Drop Down (Select) Won’t Populate

I had a recent bug that took me much too long to solve and the root of the cause was me. I got a bit too delete happy and deleted a crucial file that allows me to use Razor Tag Helpers to bring a List into a View as a Drop Down (Select).

The Error

Here’s how the error presented itself:

  • SelectList won’t populate
  • Select or DropDown is empty
  • value = Microsoft.AspNetCore.Mvc.Rendering.SelectList or
  • System.Linq.OrderedEnumerable2 [Microsoft.AspNetCore.Mvc.Rendering.SelectListItem, System.String]

Print PDF’s on Azure Using an API and RazorLight

The Problem

I recently had an issue with printing a report to PDF using Microsoft Reporting Service and a RDLC file, etc. Something similar to this. Unfortunately, it worked great in development, but refused to work once deployed into Azure. No matter what I did, I could not duck the GDI errors I kept getting, and apparently this continues through a line of various PDF exporting extensions, all of which rely on GDI for export. Turns out, I’m not alone in facing this problem and so, I decided to find a solution.

The Solution

My general idea was to use something to render my PDF view, send that view as one long html string to a free PDF microservice and get the PDF in return.…