Webservice on Navision / Microsoft Dynamics versio

问题:

Go bounty!

This question has earned me a tumbleweed badge (7 views in 7 days!), which is somehow a strong confirmation that Navision has a very limited market share, which - I suspect - should be a confirmation Navision is neither all that great piece of software...

But hey... that's what we got as a back-end, so I am ready to fight with this. :-O

If there is some daring navision developer who is able to shed light onto this... the bounty is there for you! :)

---

Original Post

I have recently implemented a rather complex e-commerce system that interacts with a legacy back-end based on Navision 5. So far the exchange of data between the two platform has happened via XML files, but this method is quite clumsy and very much prone to mishaps.

Our needs are:

1. To expose certain elements of the business logic of each platform to the other one (for example: "what's the total amount ever purchased by this customer?", "what are the products currently on offer?", "how many new customers have registered on the website?", etc...).
2. To have mechanisms of feed-back / validation for the various transactions (for example: "Here's the a new order from customer X" ... "Ok, got it, the order will now start to be processed" ... "Ok, copy that, bye!").
3. If possible, avoid playing around with files, but keeping all of this happening in terms of calls/ports/services...

The most natural way I could think of would be to integrate the two systems via webservice, but Navision 5 does not support this natively. So I did my "due diligence" and found a few things on MSDN including this article and this other one.

According to these articles it should not be that difficult to create a webservice on Navision 5, but when I suggested this solution to the team in charge of the legacy system, they told us that it is "pure theory" and they do not know of anybody who ever implemented it.

I have no reason to doubt their word, but mileage can vary... and I thought that maybe in the SO community there are professionals from other countries who actually implemented something similar and are available to share their experience.

So, my question is two-folded:

1. Is there anybody who has tried this at home and would be available to share a bit on what have been the greatest difficulties, if the final result is reliable, if they think the outcome is worth the effort, etc... ?
2. Is there anybody who faced a similar problem but solved it with a different approach and that would be available to present their solution ("I never did it myself, but if I had to do it I would do it like this..." type of answers are also welcome)?

Thank you in advance for your time! :)

回答1:

I too will chime in with a not-too helpful answer about Nav 6 :)

I've just completed a project using Nav 6. Suprisingly, the webservices are VERY easy to expose and consume. It's really a trivial matter to go find a object in the webservices interface and tick a box to tell it to expose itself.

Unsuprisingly, the webservices don't work as you'd expect, you have to often use some trial-and error to get objects and properties to persist, as it's really touchy as to the sequence of events you use to save and object. And each object seems to work slightly differently. eg: To create a customer, I eventually found out that you have to create and save a blank customer, massage this new record with a codeunit, then fetch the record and then write the customer's attributes and save again. I expected to just create a new customer(), set the attributes and save in one quick swoop.

I guess you're not too keen on upgrading to Nav6, but off the top of my head, Here is how you could simulate web services:

Sharepoint can already consume and expose webservices, so that tier isn't a problem. Nav 5 doesn't have them 'naturally', but you could cook up your own program that acts as a webservice 'broker' - you're already getting info into and out of nav, via mostly XML. You could build this broker to take input as the xml files and massage them to use in a webservice call. You could even forgo the XML and write and read directly from the Db, as all the Nav info is stored there anyway. So here's what I'm thinking:

NAV <-> SQL SERVER <-> New 'broker' webservice <-> Sharepoint

Or if you already have the NAV API down pat and want to resuse your XML:

NAV <-> XML files <-> New 'broker' webservice <-> Sharepoint

If you are using XML and use filewatchers, the latency shouldn't be too bad, usually filewatchers pick up on a drop or change in milliseconds.

Hmm, but I'm thinking you are probably supposed to use BizTalk for stuff like this: NAV <-> BizTalk <-> Sharepoint

But I don't know how easy it would be to set up BizTalk to communicate with Nav. I'll bet that it's pretty straighforward to get comms working, but this is speculation.

In any case, I don't know how helpful this post is, but maybe it gives you a few ideas to go with.

Cheers, Lance

回答2:

Where I work, we were able to use one of the web services from NAV 6 to integrate with SharePoint, so you can look up a customer or record and show it in a web part in SharePoint. I know your question is about NAV 5 in particular, but I have only seen this working on NAV 6. And I wasn't the developer who worked on this, so I don't have any more specifics I'm afraid.

Did you try asking on mibuso.com? They're much more Navision-focused.

回答3:

When you say expose business logic, does this include executing AL code (e.g. a CodeUnit)? If you only need to perform queries against the database you could use NODBC & System.Data.Odbc or the CFront .NET API. Either of these can easily be wrapped using a .NET web service, and both support the native NAV database. To pass messages back you would still need to use COM, as described in the first article you mention.

Any of the above are entirely possible, and relatively easy depending on your proficiency in .NET, COM and NAV.

The second article you linked to describes using the NAS. I'm no expert on this, but I think this might require a special license granule. Before spending time implementing anything its worth checking whether your license includes the NAS, CFront or NODBC.

回答4:

You can actually do a "technical upgrade" of NAV 5 to NAV 2009 and then use the native webservices. Meaning replacing the exe-files and the entire application (but not the objects, which will still be version 5), and a couple of other tricks. But it works, and thus you have 2009-webservice-functionality on your NAV 5 :-)

回答5:

For the benefit of anyone googling this, if you're still on Navision 6 with the native database, a good way of connecting it is via the windows message queue.

You can write your own web service that puts XML requests into the queue and then wait for the reply to pop up. On the Navision side, you have one clients that pulls the queue and puts answers into the reply queue. There's a special non-GUI client called NAS for that.

I've been using this approach for 15 years to connect booking engines to out Navision back end. It works very well and has the advantage that you can peek at requests before they reach Navision, so you can protect your back end from too many or faulty requests.

The only problem with this approach is that the COMMIT command within Navision is super expensive. It's difficult to serve high volumes of requests. As soon as the back end needs committing, you are down to just a few requests per second. This may be fine for low volume.

For high volume you need to implement caching or getting some of the business logic out. For me it was getting hit by price comparison websites, so here the solution is serve those from web services written in Python and only pass on the requests if someone buys something...