EF 4.3 Code First Migrations - Uncompress __MigrationHistory Model - ef-code-first

How can I uncompress/read the compressed models stored in the EF 4.3 Code First Migrations __MigrationHistory table?
I found a hint in this comment, that I can uncompress it using zip/gzip, but I don't know how exactly I should do this.
The problem is that I have changed something in my ef model classes, but when I call "add-migration" an empty migration ist generated. I think that is because the changes of my model classes are already assigned to an existing migration :(

(this may be a good starting point - won't work in your case)
I think you may find this useful - you 'just' need to work it out in the opposite direction, I think (I'm just hinting here as to what might be the direction, you'll have to check it out, test yourself)...
http://brice-lambson.blogspot.com/2012/05/using-entity-framework-code-first-with.html
It uses the following code...
private byte[] GetModel(TContext context)
{
using (var memoryStream = new MemoryStream())
{
using (var gzipStream = new GZipStream(
memoryStream,
CompressionMode.Compress))
using (var xmlWriter = XmlWriter.Create(
gzipStream,
new XmlWriterSettings { Indent = true }))
{
EdmxWriter.WriteEdmx(context, xmlWriter);
}
return memoryStream.ToArray();
}
}
to serialize the model.
However, as I understand (if I understand it properly) you need it in the other direction...
Quick search didn't show the equivalent reader - you can download the latest EF6 code - or also find EF5 one (I'll link in later if needed).
Reader:
Actually this may be closer to what you want:
http://edmxdom.codeplex.com/
(I haven't tried it out but was linked from MS)
http://social.msdn.microsoft.com/Forums/en-US/adodotnetentityframework/thread/1546548f-9f90-4cc2-b1b2-28cf7e9d1cb5/
And check the response about using MetadataWorkspace
If you need more info on the MetadataWorkspace I'll post some posts I made on that subject. You can get most info out - you'll need to sort 'reverse' what EdmxWriter is doing.
Essentially, you're looking for entity framework Edmx reader.
EdmxDOM:
I just checked it out fast - and it seems to be doing the Edmx format management you need.
It's a 'VB' project - but you can work through that
There is what seems to be a 'reader' (again, not sure, just went through this, as I know about the writer - but never worked w/ this part, direction)...
Public Sub LoadFile(ByVal fileName As String)
In the Edmx.vb

Related

Is there a way to import multiple enumerands in IBM Rhapsody?

I have an enumerand of around 150 entries, which I need to get into IBM Rhapsody.
Doing this by hand is clearly lengthy and error prone. I have google extensively but found only things that tell me how to edit the generated code -- not go the other way.
The question is: How is this done? And if there is no way -- please someone post that as an answer.
David,
I would jump into the Java API (plugin subsystem) and do it that way. If you haven't learned how to use the API, there is a bit of a learning curve. There are two ways to go about it: Implement a Java (or your favorite JVM language--I use Scala) app that realizes the Rhapsody Plugin framework and then you choose to package it up and deploy it so that it gets loaded when you load your model, or, if it is a one off job, do everything up to the point of packaging it up and then run it from within your IDE and you are done. If you are comfortable with Scala, I can post some code.
So what I did in the end was I edited the relevant .sbs file, used a small python program to generate the items I required, and then update the length of the array accordingly.
all_the_literals = ["enum_name = 0x4e", enum_name2 = 0xF2", ... ,]
for field1, waste, field1_value in map(lambda x: x.split(" "),
all_the_literals):
literal_string = f""" {{ IEnumerationLiteral
- _id = GUID {uuid.uuid4()};
- _name = \"{field1}\";
- codeUpdateCGTime = 5.16.2022::19:24:18;
- _modifiedTimeWeak = 5.16.2022::19:24:18;
- _value = \"{field1_value}\";
}}"""
print(literal_string)
Note the above "code" snippet purely prints the items, which you then copy-paste into the relevant field in the sbs file. YMMV -- this was the correct format for an enum in Rhapsody (and note how I fudged the update time, but it worked successfully, so you'll need to do the same if you use this answer).
Also note it's probably better to use bauhaus9's answer, but I definitely didn't have time for it.

Entity Framework Core SQLite How to use relative Data Source

In a current Project of mine I am using Entity Framework Core together with SQLite in an ASP.Net-Project.
My Problem is, that the Database in the project-files is used, instead of the one in the ./bin-Directory
I followed the instructions of the docs.microsoft-page to create the database:
https://learn.microsoft.com/de-de/ef/core/get-started/overview/first-app?tabs=visual-studio
This is the Connectionstring I am using.
protected override void OnConfiguring(DbContextOptionsBuilder options)
=> options.UseSqlite("Data Source=MySqliteDatabase.db");
I let the created Database be copyied over, when newer.
I browsed through a number of pages, looking for ways to provide a relative Database path, but I couldnt find a solution to this. It either still uses the project-DB-File, or it wont create the new Database, because it cant be opened, or so.
Does anyone have a solution to this? I noticed that Entity-Framework-Core-5 is kind of a new release, could this be a bug or similar of this particular version?
Thanks #Sergey and #ErikEJ.
So to solve this, I really needed to provide the full path of the directory.
Since Directory.GetCurrentDirectory returned the wrong path, that is, the path to the project-directory instead of the /bin/Debug/... , I looked at the path that is named in the Config-File, as #Sergey suggessted, using the following Code:
AppDomain.CurrentDomain.SetupInformation.ApplicationBase
I got this from the following Stackoverflow page:
How to find path of active app.config file?
It said there, to access the ConfigurationFile-Property, but for ASP.Net it is ApplicationBase I guess.
In there was the correct path, the one of the /bin/Debug/... .
Put together, my new Method looked like this:
protected override void OnConfiguring(DbContextOptionsBuilder options)
{
string databasePath = $"{AppDomain.CurrentDomain.SetupInformation.ApplicationBase}MySqliteDatabase.db";
options.UseSqlite($"Data Source={databasePath}");
}
This works for me as intended, thanks alot for the support, maybe this will help someone else as well.

Are there solutions for streamlining the update of legacy code in multiple places?

I'm working in some old code which was originally designed for handling two different kinds of files. I was recently tasked with adding a new kind of file to this code. Most of my problems were solved by filling out an extensive XML file with a new entry that handled everything from what lists were named to how the file is written in plural lower case. But this ended up being insufficient, as there were maybe 50 different places in 24 different code files where I had to update hardcoded switch-statements that only branched for the original two file types.
Unfortunately there is no consistency in this; there are methods which operate half from the XML file, and half off of hardcode. Some of the files which look like they would operate off of the XML file don't, and some that I would expect that I'd need to update the hardcode don't need it. So the only way to find the majority of these is to run through testing the whole system when only part of it is operational, finding that one step to fix (when I'm lucky that error logging actually tells me what is going on), and then running the whole thing again. This wastes time testing the parts of the code which are already confirmed to work, time better spent testing the new parts I have to add on top of it all.
It's a hassle and a half, and to my luck I can expect that I will have to add yet another new kind of file in the near future.
Are there any solutions out there which can aid in this kind of endeavour? Something which I can input some parameters of current features, document what points in a whole code project actually need to be updated, and run something nice the next time I need to add a new feature to the code. It needn't even be fully automated, something that'll help me navigate straight to the specific points in everything and maybe even record what kind of parameters need to be loaded.
Doubt it matters specifically, but the code is comprised of ASP.NET pages, some ASP.NET controls, hundreds of C# code files, and a handful of additional XML files. It's all currently in a couple big Visual Studio 2008 projects.
Not exactly what you are describing, but if you can introduce a seam into the code and lay down some interfaces you can break out and mock, a suite of unit/integration tests would go a long way to helping you modify old code you may not fully understand well.
I completely agree with the comment about using Michael Feathers' book to learn how to wedge new tests into legacy code. I'd also strongly recommend Refactoring, by Martin Fowler. What it sounds like you need to do for your code is to implement the "Replace conditionals with polymorphism" refactoring.
I imagine your code today looks somewhat like this:
if (filetype == 23)
{
type23parser.parse(file);
}
else if (filetype == 69)
{
filestore = type69reader.read(file);
File newfile = convertFSto23(filestore);
type23parser.parse(newfile);
}
What you want to do is to abstract away all the "if (type == foo)" kinds of logic into strategy patterns that are created in a factory.
class FileRules : pReader(NULL), pParser(NULL)
{
private:
FileReaderRules *pReader;
FileParserRules *pParser;
public:
void read(File* inFile) {pReader->read(inFile);};
void parse(File* inFile) {pParser->parse(inFile);};
};
class FileRulesFactory
{
FileRules* GetRules(int inputFiletype, int parserType)
{
switch (inputFiletype)
{
case 23:
pReader = new ASCIIReader;
break;
case 69:
pReader = new EBCDICReader;
break;
}
switch (parserType)
... etc...
then your main line of code looks like this:
FileRules* rules = FileRulesFactory.GetRules(filetype, parsertype);
rules.read(file);
rules.parse(file);
Pull off this refactoring, and adding a new set of file types, parsers, readers, etc., becomes as simple as writing one exclusive to your new type.
Of course, go read the book. I vastly oversimplified it here, and probably got stuff wrong, but you should get the general idea of how to approach it from this. I can also recommend another book, "Head First Design Patterns", which has a great section on the Factory patterns (if you like those "Head First" kinds of books.)

array of loaders?

How does one create an array of loaders?
The bigger picture:
I have written a mapping program in flex. I want to change my mapping program so that all I need to do is drop in a new xml file instead of going into my flex file and adding the exact number of item loaders I need. So I guess I'm looking for an array of loaders that can load the image files that are within my XML file.
xml file example:
<locations>
<location>
<name>Big Star</name>
<street>123 Some St.</street>
<city>City</city>
<state>XX</state>
<zip>555555</zip>
<lat>12.34567</lat>
<long>-67.54321</long>
<iconFile>bigStar_icon.gif</iconFile>
<imageFile>bigStar_img.swf</imageFile>
<motion>no</motion>
<featured>yes</featured>
<category>Grocery</category>
</location>
</locations>
this xml can sometimes have 2000 locations.
Yeah, that's a pretty bad question. Literally (if facetiously):
var loaders:Array = [new Loader(), new Loader()];
Trying to read into what you asked, it sounds like you are trying to load up a whole bunch of stuff and handle them all loading together somehow... and if you have to ask, you're going to struggle.
You could try using the Bulk Loader library though, which does this for you reasonably well. There are probably others.
Not a direct answer to the question since it's a bit vague + #alecmce already gave an answer (I would go for a loader queue such as BulkLoader in this situation as well).
However, since I noticed a similar question some time ago I just wanted to point out that instantiating all the loaders at once just feels a bit wrong.
Wouldn't it be a bit appropriate to just store the urls and handle process them one by one ?
Basic example :
(beware I typed it in without testing...)
// So here's the point: only Strings are stored ...
var urls:Array = new Array('image1.jpg','image2.jpg',image3.jpg);
loadNext();
function loadNext()
{
if(urls.length() == 0)
return;
load(urls.shift())
}
function load(url:String):void
{
// The loader is created lazily just before before we need it
var loader:Loader = new Loader(new URLRequest(url));
loader.contentLoaderInfo.addEventListener(Event.COMPLETE, onLoaded)
loader.load(url);
}
function onLoaded(e:Event):void
{
event.target.removeEventListener(Event.COMPLETE, onLoaded);
addChild(event.target.content); // ... or whatever has to happen here.
loadNext();
}

Can't set up asp.net mvc 2 RC and spark view engine

Does omebody has ideas how to fix "Method not found: 'Void System.Web.Mvc.ViewContext..ctor(System.Web.Mvc.ControllerContext, System.Web.Mvc.IView, System.Web.Mvc.ViewDataDictionary, System.Web.Mvc.TempDataDictionary)'." exception. This solution doesn't work http://dotnetslackers.com/articles/aspnet/installing-the-spark-view-engine-into-asp-net-mvc-2-preview-2.aspx.
Thans for all.
I had to download the spark view engine source code (http://sparkviewengine.codeplex.com/Release/ProjectReleases.aspx?ReleaseId=27600). Once I did that I went through each of the projects that had a reference to the 1.0 version of System.Web.Mvc assembly and updated to reference to point to System.Web.Mvc 2.0. From there you can build the solution (in visual studio) and you will find that a whole bunch of tests start to fail. You can attempt to fix them (by adding the additional TextWriter parameter you will find is now needed). You will also see that the SparkView.cs file complains about a missing parameter. In the Render method (line 100 of the source code I downloaded) I had to update the instantiation of the wrappedViewContext to look like this (add writer to the end of the list of parameters):
public void Render(ViewContext viewContext, TextWriter writer)
{
var wrappedHttpContext = new HttpContextWrapper(viewContext.HttpContext, this);
var wrappedViewContext = new ViewContext(
new ControllerContext(wrappedHttpContext, viewContext.RouteData, viewContext.Controller),
viewContext.View,
viewContext.ViewData,
viewContext.TempData,
writer); // <-- add the writer to the end of the list of parameters
...
}
Once the code is updated you can run the build.cmd script that is in the root of the source you downloaded. The build process will create a zip file in the build/dist folder. Take those new dll's and add them to your website. Things should work once again.
At the time of this answer, MVC 2 RC2 bits are available at sparkviewengine.codeplex.com
http://sparkviewengine.codeplex.com/releases/view/41143
It was actually Erik from the post mentioned by R0MANARMY who helped get those bits out there.
Looks like you can also download compiled binaries from here. As the post says, it isn't a final (or official) release, but at least it seems like the unit tests pass.

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