Windows Workflow 4.0 for Simple Orchestration? - xaml

I have 4 classes, each with a couple of methods (all the same, they implement a common Interface) and a Dictionary<> containing stuff the instances need to know to do work. They operate serially, "A" finishes and then writes some stuff to state (either file or a DB), then "B" does its work, then "C", then "D". Right now a console app just runs each.
I will soon come on a time when I need to put something between "A" and "B", and later "C" and "D". You get the idea.
I thought that Windows Workflow on Framework 4.0 would be a good candidate for simple sequence orchestration. So I added a new XAML file, fired up the designer, and.... I'm not sure what to do next. I just want to instance objects and set their Dictionary and run them.
How can I get started with that? Simple orchestration searches on Google are not helping.
Thanks.

In order to help the next WF newbie:
Open the designer.
Drag a "Sequence" onto the design surface.
Drag an "InvokeMethod" inside the Sequence.
Target type should be null for Instance Types.
Target object should be "New my.namespace.my.class" (note New is VBasic syntax, required even if you are doing C#)
MethodName should have the name of the method you want to call.
Get Properties and click the elipsis and add the properties in the same order as they are specified in the class definition in your code.
Done.
I stumbled for a while until I found the right word to Bing for - InvokeMethod is the sweetness that lets you run custom code as an activity. There are at least 99e99 other ways to do it I am sure, but this is what works for me.
Thanks.

Related

How to differentiate if a TBO is called when importing new Document vs for any other operations

We are trying to add one additional feature to our method for TBO. The feature needs to be executed only when a new document for that object type is imported and should not be executed in any other case like checkin checkout or any changes in attributes.
However the new code is getting called everytime we make any changes to attribute to that document.
We have put that code in doSave() method.
I tried isNew method for distinguish between newly imported Document and other scenarios, however could not get success, may be missing the usage details of the method.
Can anyone suggest anything?
We are on Documentum version 7.2.
I always use isNew() method to check is object new or versioned, I don't remember having problems with it at any DFC version.
Only one thing that comes in mind is to make sure you don't use super.doSave() while inside the code since right after it method will return false.
But this is expected behaviour.
If you really need to do this - some calulations based on programatically preset data - make sure you use value saved within local variable throughout your code.
If you think you are experiencing bug with the method try with another DFC version or report a bug to the Support.

noflo-ui: Load and save projects/graphs/components from external database or api

I'm trying to create a custom build of noflo-ui that is effectively only a graph editor. Don't need it to connect to any runtimes.
I'm struggling to find where I can inject this code as it appears part of noflo-ui is written in noflo itself and I cannot find the scripts for those pieces.
For example, in graphs/main.fbp, there is this line:
'user,main,project,github,runtime,context' -> ROUTES Dispatch
Three questions on this:
Where is the source behind the Dispatch component?
If I add my own interface elements to Load data from an external api, where would be the best place to inject that data?
I see a lot of event driven code, so I'm guessing I would add a new polymer element, do my ajax call, the emit or fire something. I believe this is what happens when connecting to a noflo-nodejs runtime; I've traced the connection to line 51312 in a built noflo-ui.js
return port.send({
componentDefinition: definition
});
... but I can't figure out where it goes past here. A port on the main.fbp graph? As per my 1st question, I cannot find the source behind these core graphs.
And this leads to my last question
The code I pasted above from noflo-ui, I cannot find this code anywhere pre-build. I even searched the entire project tree for "componentDefinition: definition". Where is this coming from?
Any pointers on this would be greatly appreciated! Thanks
The FBP runtime protocol is the primary extension point of noflo-ui. You can implement a "runtime" which just provides components and graphs (for instance from a database), without a way to run these.
A network:persist message to let the UI indicate that "this is a good point to save the graphs" has been specced but is currently not implemented. For now you can just autosave latest state.

A program sharing TEXT with its copy (opened twice)

What i'm trying to do, is a simple program where i have 2 textboxes, and a button.(there is more but no need to say for resolving my problem)
When i write text in the 1st textbox and click the button, it will be written in the 2nd textbox. Everything is ok here.
Now, when i run this program more than once, i want the text to be written in the 2nd textbox of the others programs.
Sorry for the bad explaination i gave you before, hope it's better :)
OLD DESCRIPTION
i'm actually trying to make a program that works pretty much like a
messenger (basically 2 textboxes, 1 to send, 1 to view, and a button
to send) and i can't figure out how to link the program with itself
(copies). I want it to be able to read the textboxes contained
in the other copies and i don't want it to be 1 program with 2 forms,
but 1 single form, running severeal times (2 or more) How can i
do that? /!\ NOTE : It will be on a single computer, just like 2
forms!
I am assuming you are doing this in WinForms and only running one executable.
Sounds like you you want to create a single instance of a class that is shared between several forms. It should raise an event when the values change. After you create each instance of your form you pass in the class. In the form you would declare it With Events. When one form updates the class it would raise an event notifying the other forms to refresh themselves.
If you are familiar with WPF and MVVM this sort of design would be a little cleaner, but that takes some time to get up to speed on.
This design would not be appropriate if you want to run seperate applications and communicate between them.
You will have to do some kind of IPC, respectively remoting.
You could use:
anonymous pipes
named pipes
UDP
TCP
WCF (would be overkill IMHO)
windows messaging (would be the easiest way)

LINQPad Dump() method not working for Sharepoint Client Object Model

I'm using LINQPad (2.42) to test some snippets that make use of SharePoint Client Object Model.
Basically messing with SPSite, SPWeb, SPList, SPFolder and SPFile.
The problem is that LINQPad seems to dislike calling .Dump() for any of the previous objects. It just keeps "Executing" for ever without showing any results.
Does anyone experience the same problem? Any workaround or fix?
Thanks
Try calling .Dump(0) to only dump the first level of Properties, or dumping the results to a Grid.
I have not looked at the SharePoint Client Objects but if they are anything like the TFS API classes, some of the properties are lazy loaded. Calling .Dump() will walk it's way down each every single result making server calls for every property (and property of property, etc.). This is probably what's taking the time.

How should one class request info from another one?

I am working on a VB.NET batch PDF exporting program for CAD drawings. The programs runs fine, but the architecture is a mess. Basically, one big function takes the entire process from start to finish. I would like to make a separate class, or several, to do the exporting work.
Here's the problem:
Sometimes the pdf file which will be created by my program already exists. In this case, I would like to ask the user if he/she would like to overwrite existing PDFs. I only want to do this if there is actually something which will be overwritten and I only want to do this once. In other words, "yes" = "yes to all." It seems wrong to have the form (which will be calling this new PDF exporting class) figure out what the PDF files will be called and whether there will be any overwrites. In fact, it would be best to have the names for the PDF files determined as the individual CAD drawings are processed (because I might want to use information which will only become available after loading the files in the CAD program in the background).
Here's the question:
How should I handle the process of prompting the user? I would like to keep all GUI logic (even something as simple as a dialog box) out of my PDF exporting class. I need a way for the PDF exporting class to say, "Hey, I need to know if I should overwrite or skip this file," and the form class (or any other class) to say, "Um, ok, I'll ask the user and get back to you."
It seems there ought to be some pattern to handle this situation. What is it?
Follow-ups:
Events: It seems like this is a good way to go. Is this about what the code should look like in the PDF exporting class?
Dim e As New FileExistsEventArgs(PDFFile)
RaiseEvent FileExists(Me, e)
If e.Overwrite Then
'Do stuff here
End If
A crazy idea: What about passing delegate functions to the export method of the PDF exporting class to handle the overwrite case?
You could use an Event, create a custom event argument class with a property on it that the application can call. Then when your app is handling the event prompt the user and then tell the exporter what to do. I'm a c# guy so let me give you a sample in there first:
void form_Load(object sender,EventArgs e)
{
//We are subscribing to the event here. In VB this is done differently
pdfExporter.FileExists+=new FileExistsEventHandler(pdfExporter_fileExists)
}
void pdfExporter_fileExists(object sender, FileExistsEventArgs e)
{
//prompUser takes the file and asks the user
if (promptUser(e.FileName))
{
}
}
Your PDF making class should raise an event. This event should have an eventargs object, which can have a boolean property called "Overwrite" which the GUI sets in whatever fashion you want. When the event returns in your PDF class you'll have the user's decision and can overwrite or not as needed. The Gui can handle the event anyway it likes.
Also, I commend you for working to keep the two seperate!
So the appropriate method on your class needs an optional parameter of
[OverwriteExisting as Boolean = False]
However your form will need to handle the logic of establishing whether or not a file exists. It seems to me that this would not be a function that you would want encapsulated within your PDF export class anyway. Assuming that your form or other function/class ascertains that an overwrite is required then the export methos is called passing True as a Boolean to your export class.
You could do a two phase commit type of thing.
The class has two interfaces, one for prepping the filenames and filesystem, and another for doing the actual work.
So the first phase, the GUI calls the initialization interface, and gets a quick answer as to whether or not anything needs over-writing. Possibly even a comprehensive list of the files that will get over-written. User answers, the boolean variable in the other responses is known, and then the exporter gets to the real work, and the user can go do something else.
There would be some duplication of computation, but it's probably worth it to get the user's part of the operation over with as soon as possible.
You can't keep the GUI stuff out of the PDF Exporting Code. but you can precisely define the minimum needed and not be tied to whatever framework you are using.
How I do it is that I have a Status class, and a Progress class. The two exist because Status is design to update a status message, and the Progress Bar is designed to work with a indicator of progress.
Both of them work with a object that has a class type of IStatusDisplay and IPrograssDisplay respectfully.
My GUI defines a object implementing IStatusDisplay (or IProgressDisplay) and registers as the current display with the DLL having Status and Progress. The DLL with Status and Progress also have two singleton called NullStatus and NullProgress that can be used when there is no UI feedback wanted.
With this scheme I can pepper my code with as many Status or Progress updates I want and I only worry about the implementations at the GUI Layer. If I want a silent process I can just use the Null objects. Also if I completely change my GUI Framework all the new GUI has to do is make the new object that implements the IStatusDisplay, IProgressDisplay.
A alternative is to raise events but I find that confusing and complicated to handle at the GUI level. Especially if you have multiple screen the user could switch between. By using a Interface you make the connection clearer and more maintainable in the longe.
EDIT
You can create a Prompt Class and a IPromptDisplay to handle situation like asking whether you want to overwrite files.
For example
Dim P as New Prompt(MyPromptDisplay,PromptEnum.YesNo)
'MyPromptDisplay is of IPromptDisplay and was registered by the GUI when the application was initialized
If PromptYesNo.Ask("Do you wish to overwrite files")= PromptReply.Yes Then
'Do stuff here
End If