Question

Important: This question isn’t actually really an ASP.NET question. Anyone who knows anything about URLS can answer it. I just happen to be using ASP.NET routing so included that detail.

In a nutshell my question is :

‘What URL format should I design that i can give to external parties to get to a specific place on my site that will be future proof. [I’m new to creating these ‘REST’ URLs].’

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I need an ASP.NET routing URL that will be given to a third party for tracking marketing campaigns. It is essentially a ‘gateway’ URL that redirects the user to a specific page on our site which may be the homepage, a special contest or a particular product.

In addition to trying to capture the referrer I will need to receive a partnerId, a campaign number and possibly other parameters. I want to provide a route to do this BUT I want to get it right first time because obviously I cant easily change it once its being used externally.

How does something like this look?

routes.MapRoute(    '3rd-party-campaign-route',    'campaign/{destination}/{partnerid}/{campaignid}/{custom}',    new    {        controller = 'Campaign',        action = 'Redirect',        custom = (string)null // optional so we need to set it null     } );  

campaign : possibly don’t want the word ‘campaign’ in the actual link — since users will see it in the URL bar. i might change this to just something cryptic like ‘c’.

destination : dictates which page on our site the link will take the user to. For instance PR to direct the user to products page.

partnerid : the ID for the company that we’ve assigned – such as SO for Stack overflow.

campaignid : campaign id such as 123 – unique to each partner. I have realized that I think I’d prefer for the 3rd party company to be able to manage the campaign ids themselves rather than us providing a website to ‘create a campaign’. I’m not completely sure about this yet though.

custom : custom data (optional). i can add further custom data parameters without breaking existing URLS

Note: the reason i have ‘destination’ is because the campaign ID is decided upon by the client so they need to also tell us where the destination of that campaign is. Alternatively they could ‘register’ a campaign with us. This may be a better solution to avoid people putting in random campaign IDs but I’m not overly concerned about that and i think this system gives more flexibility.

In addition we want to know perhaps which image they used to link to us (so we can track which banner works the best). I THINK this is a candiate for a new campaignid as opposed to a custom data field but i’m not sure.

Currently I am using a very primitive URL such as http://example.com?cid=123. In this case the campaign ID needs to be issued to the third party and it just isn’t a very flexible system. I want to move immediately to a new system for new clients.

Any thoughts on future proofing this system? What may I have missed? I know i can always add new formats but I want to use this format as much as possible if that is a good idea.

Answer 1

This URL:

'campaign/{destination}/{partnerid}/{campaignid}/{custom}', 

…doesn’t look like a resource to me, it looks like a remote method call. There is a lot of business logic here which is likely to change in the future. Also, it’s complicated. My gut instinct when designing URLs is that simpler is generally better. This goes double when you are handing the URL to an external partner.

Uniform Resource Locators are supposed to specify, well, resources. The destination is certainly a resource (but more on this in a moment), and I think you could consider the campaign a resource. The partner is not a resource you serve. Custom is certainly not a resource, as it’s entirely undefined.

I hear what you’re saying about not wanting to have to tell the partners to ‘create a campaign,’ but consider that you’re likely to eventually have to go down this road anyway. As soon as the campaign has any properties other than the partner identifier, you pretty much have to do this.

So my first to conclusions are that you should probably get rid of the partner ID, and derive it from the campaign. Get rid of custom, too, and use query string parameters instead, should it be necessary. It is appropriate to use query string parameters to specify how to return a resource (as opposed to the identity of the resource).

Removing those yields:

'campaign/{destination}/{campaignid}', 

OK, that’s simpler, but it still doesn’t look right. What’s destination doing in between campaign and campaign ID? One approach would be to rearrange things:

'campaign/{campaignid}/{destination}', 

Another would be to use Astoria-style indexing:

'campaign({campaignid})/{destination}', 

For some reason, this looks odd to a lot of people, but it’s entirely legal. Feel free to use other legal characters to separate campaign from the ID; the point here is that a / is not the only choice, and may not be the appropriate choice.

However…

One question we haven’t covered yet is what should happen if/when the user submits a valid destination, but an invalid campaign or partner ID. If the correct response is that the user should see an error, then all of the above is still valid. If, on the other hand, the correct response is that the user should be silently taken to the destination page anyway, then the campaign ID is really a query string parameter, not a part of the resource. Perhaps some partners wouldn’t like being given a URL with a question mark in it, but from a purely REST point of view, I think that’s the right approach, if the campaign ID’s validity does not determine where the user ends up. In this case, the URL would be:

'campaign/{destination}', 

…and you would add a query string parameter with the campaign ID.

I realize that I haven’t given you a definite answer to your question. The trouble is that most of this rests on business considerations which you are probably aware of, but I’m certainly not. So I’m more trying to cover the philosophy of a REST-ful URL, rather than attempting to explain your business to you. 🙂