I am reading book, Practical JBoss Seam Project. In the page 74, author mentioned "motivation for conversations". The concept is to handle multiple pageflow that user can have different sessions for the same page. For details to click here. I google this idea about conversation but I can't get good answer. My question is if I don't use Seam, is there other way to perform the same result?
If I do not use Seam, is there other way to perform the same result ?
Short answer: Session attribute
But keep in mind conversation is handled transparently in a Seam application. You just especify its boundaries - begin-conversation and end-conversation.
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Currently i am creating a design for a new enterprise application. Right now we have a lot of different proprietary solution and we wanna create a new one to switch from them all.
Briefly it is a kind of data destribution system. We have a lot of clients who needs a lot of different data.
What do i want:
1) Common REST API service
2) Some synchronoyu(async?) enviroment to send task and get data back. On image below you could see i think to use spring kafka request/reply template. It helps to scale my application in future.
3) Different typec of calculators for every kind of data
I search a lot how to do the second point the best way but didn't find any ready solutions or advices. Is it good to use kafka here? Maybe some one could give me advice about best practice in such situations.
Plz, send me links for articles or something else, because it will be a big application and i wanna start to create it rightly from the beginning.
I've been using this site for quite a while, usually being able to sort out my questions by browsing through the questions and following tags. However, I've recently come across a question that is rather hard to lookup amongst the great number of questions asked - a question I hope some of you might be able to share your opinion on.
As my problem is a bit hard to fit into a single line, going in the title, I'll try to give a bit more details on the problem I've encountered. So, as the title says I need to filter, or limit, some of the response data my standard ASP.NET Soap-based Web service returns on invoking various web methods. The web service is used to return data used by other systems (a data repository more or less), where the client today is able to specify a few parameters on how the data should be filtered and in return a full-set of data back.
Well, easy enough I thought, just put additional filtering options on the existing web methods which needs a bit more filtered applied, make adjustments on the server-side and we are all set to go - well, unfortunately it turned out to be a bit more tricky then this.
The problem I am facing is that I'm working on a web service running in a production environment, which needs to be extended in such that additional filters can be applied to existing web method being invoked w/o affecting the calls already being made by other systems used by the customer using their client stubs. This is where I am a bit troubled, since I can't seem to find a "right solution" on extending the current web service.
Today, the filter is send as a custom data structure which holds information on which data should filtered, but I am not sure if I can simply just add more information to this data structure w/o breaking code at the clients? One of my co-workers suggested that I could implement a solution where I would extend the web.config on the server-side to hold a section with details on which data should be excluded (filtered out), but I don't find this to be a viable solution long-sighted - and I don't trust customers with such an option since this is likely to go wrong at some point. So the solution I am looking for is a way that I can apply a "second filter" to the data I am requesting from the client so instead of getting a full-set of data back it should only give a fraction, it implemented in such that the filter can be easily modified and it must not affect the current client calls.
Any suggestions on how I should approach this problem?
Thanks!
Kind regards,
E.
A pretty common practice is to create another instance of the application OR use part of the url to signify the version of the endpoint they are connecting to, perhaps the virtual directory is the date. That way old calls will go to the old API and new calls will come in on the new API.
http://api.example.com/dostuff
vs
http://api.example.com/6-7-2011/dostuff
For an MVC 2 app that relies on many partial views and almost exclusively uses Ajax for POSTs/GETs, what would be the best way to implement the setting, passing, retrieval and display (using a JavaScript modal) of these messages?
My forms all POST (by way of jQuery $.ajax) to actions that return partial views (html) that are used to update a in the "success:" part of the $.ajax function.
I was hoping for some sort of mechanism in the master view that could "listen" for any messages that any of these partial views might be "delivering"--through their ViewData, for instance.
Thanks.
Edit:
After lots more searching, I found similar people trying to achieve the same thing as me, but none of the questions had a good answer. This one states the question best.
Your "master view" wouldn't be able to have a mechanism like what you're thinking of simply because you're asking it to be aware of potential data that could be given to it based on a possible user interaction.
What I think #cottsak is trying to say is to have delegate functions in your JS code that handle error and success events. Thus you can have 100 Ajax requests but only 2 functions actually handling the response. Within these functions you'll have to normalize the way you deal with the responses so that you don't have to write conditionals for specific forms for example. This might require normalizing your forms to have identical structures and base functionality and differ only on their input content.
For example I use "Wizards" in some of my sites that deal with modal forms:
<div class="Wizard">
<form>
<!-- Any and all possible content -->
</form>
</div>
All my forms of course differ on the actual inputs they have, but they're all normalized in the sense that there's dedicated elements in them for messaging and such. Every single form however is controlled by the same JS with a few exceptions for special scenarios.
You should take a look at the Dropbox web interface. Get yourself a free account and use the interface for 10 mins - copy, move, delete a file. The messaging and validation system is great. And it's largely ajax on their site too. Perfect example of the user experience you want it sounds like.
As for the technical implementation, i have been thinking about this for some time:
I'd use a broker system on the client for which all page ajax requests go through. This way all responses can be collated within a single function (/object, however you design it) and thus the responses too. It's obviously the responses that are key so that Error messages and Status messages can be handled in the same place and rendered to the user in a uniform way.
Server side it wouldn't be too hard. I'd suggest that you have a graceful degradation solution to those actions that return JSON or other ajax responses, in that they can function (and return Error/Status messages) without the client having JavaScript enabled.
This question already has answers here:
Closed 13 years ago.
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How should I choose between GET and POST methods in HTML forms?
When do you use POST and when do you use GET?
Obviously, you should. But apart from doing so to fulfil the HTTP protocol, are there any reasons to do so? Less overhead? Some kind of security thing?
because GET must not alter the state of the server by definition.
see RFC2616 9.1.1 Safe Methods:
9.1.1 Safe Methods
Implementors should be aware that the
software represents the user in their
interactions over the Internet, and
should be careful to allow the user to
be aware of any actions they might
take which may have an unexpected
significance to themselves or others.
In particular, the convention has been
established that the GET and HEAD
methods SHOULD NOT have the
significance of taking an action other
than retrieval. These methods ought to
be considered "safe". This allows user
agents to represent other methods,
such as POST, PUT and DELETE, in a
special way, so that the user is made
aware of the fact that a possibly
unsafe action is being requested.
If you use GET to alter the state of the server then a search engine bot or some link prefetching extension in a web browser can wreak havoc on your site and (for example) delete all user data just by following links to your site.
There is a nice paper by the W3C about this: URIs, Addressability, and the use of HTTP GET and POST.
1.3 Quick Checklist for Choosing HTTP GET or POST
Use GET if:
The interaction is more like a question (i.e., it is a safe operation such as a query, read operation, or lookup).
Use POST if:
The interaction is more like an order, or
The interaction changes the state of the resource in a way that the user would perceive (e.g., a subscription to a service), or
The user be held accountable for the results of the interaction
Because, if you use GET to alter state, Google can delete your stuff.
When do you use POST and when do you use GET?
How should I choose between GET and POST methods in HTML forms?
If you accept GETs to perform write operations then a malicious hacker could inject somewhere links to perform an unauthorized operation. Your user clicks on a link - and something is deleted from a database. Or maybe some amount of money is transferred away from the user's account if he's still logged in to their online banking.
http://superbank.com/TransferMoney?amount=1000&recipient=2342524
Send a malicious email with an embedded image referencing this link, and as soon as the document is opened, something funny has happened behind the scenes.
GET is limited by the length of URL the browser/server can handle. This used to be as short as 256 characters.
There is atleast one situation where you want a GET to change data on the server. That is when a GET returns data, and you need to record which data was given to a user and when it was given.
If you use complex data types then it must be in a POST it cannot be in a GET. For example testing a WCF web service in a browser can only be done when the contract uses simple data types.
Using GET and POST where it is expected helps to keep your program understandable.
When you use POST, you can see the information being "posted" in the address-bar of the web browser. This is [apparently] not the case when you use the GET method.
This article was somewhere on http://www.w3schools.com/ Once I've found the exact page it was on, I'll repost. :-)
I am working on a design spec for a new application that will be heavily workflow driven.
Before I re-invent the wheel, is there a decent lightweight workflow engine that plugs into ASP.NET already around?
Basically, I'm looking for something that handles moving through a defined set of workflow pages while handling state management automatically.
If this isn't around already, I'll definitely try to abstract the engine from my app and put it on codeplex, as it would be really handy.
Any suggestions?
Note: .NET 2.0, so no WWF, though I think WWF is overkill for my needs.
EDIT: Seems like there is a legitimate need for this, and there isn't a product out there...So I might build this.
Here is what I'm picturing:
Custom Page class called WebFlowPage
All WebFlowPage's are registered in a Workflow mapper.
Each WebFlowPage has some form of state object.
A HttpHandler handles picking the appropriate WebFlowPage based upon the workflow, and populating it from the state object.
Is the workflow dynamic, or static?
If the workflows are simple, you could roll your own workflow engine.
In certain situations, it can be fairly simple, and just a couple of data tables to handle the rules, processing and state.
Alot of workflow engines are built for large scale processing (credit card applications, for example). For small scale, you should at least consider your own, which would eliminate the overhead and dependency of/on an engine.
Not sure exactly what you wish to do here, but Ra-Ajax can easily keep state at least if you want your solution ajaxified...
For reference purposes you might want to check out the Ajax Calendar sample or even the (banalistically implemented) Ajax Wizard sample. It surely beats the hell out of doing it with JavaScript...
And every time you "do something" you're in "server-land" which means you can store temporaries all the time as you wish...
The project is LGPL
(PS!
Yes I do work with it)
Building a custom workflow engine is not trivial, although it may seem simple at first. We've tried that. It depends a lot on the complexity of the logic you need it to cover.
Given the current state of the Windows Workflow Foundation and the lack of another framework that abstracts the workflow concepts, I would choose WF if you need complex logic, asynchronous handling or branches in your workflows.
Tracking your state through the workflow can be accomplished by carrying some kind of xml payload or storing the state in a database,
If your workflow is actually a sequential set of forms that need to be filled in by the user, tracking the steps and guiding the user to the next step can be accomplished with some simple custom solution.
You could take a look at the InRule engine too.
Also, there is nxBRE.
These too are mostly used for business rules.
InRule is proprietary, whereas nxBRE supports RuleML (the defacto standard).
You might need to make your own implementation for the pages, and use the rule engine as the "structure".
At this moment, I know that Sharepoint 2007 supports page workflows (using WF), but this would imply using .NET Framework 3 and deployng sharepoint.
My suggestion would be to use whatever you find more light and easier to use.
I think the term "workflow" is very open to interpretation. I have been working lately with a type of workflow that is very different from what you seem to be describing. Mine is a state machine based workflow where the state of a particular record determines what actions a user can take to move the record to the next step in the business process. So "workflow" in this instance means how the record flows from one state to another until it is finally completed.
Your usage of workflow seems to have more to do with moving a user from one page to another in a linear multi-step process, which is a completely different use case (correct me if I'm wrong). So before coming up with a general purpose "workflow" engine that anyone could use, I would recommend defining a little bit better exactly what types of situations this system would handle.
I've been using this for a few months http://objectflow.codeplex.com. Not asp specific but it may fit your needs
While browsing the web for some workflow & BPM resources, I found the following project: NetBPM. Unfortunately, the project seems to be stopped.
I don't think there is a workflow engine that will automatically handle state for you, but if you are moving through a set of pages like a process such as checkout on an ecommerce site, perhaps the ASP.NET wizard control could help you?
There are few workflow options. "Aspose" and "Skelta" are the offers I´m evaluating.
Fábio
you can use WorkFlow Engine, just read the document and run the Demo.
all of the features you need for a dynamic workflow engine they added in there.