Re: [Webmacro-devel] Input wanted!

[Lane S. <la...@op...>]

Hi Marc,

I only parsed out some of your post.

I have a servlet that maps *.tml files. And, it tries to find the 
template in the usual suspect places. I also have an action servlet to 
handle posts of data. Here is my mapping.

      <servlet-mapping url-pattern='/action/*' 
servlet-name='action-servlet'/>
      <servlet-mapping url-pattern='*.tml' servlet-name='template' />

If you want I can send you both servlets to take a look at. They are, of 
course, supported by composition. Nothing really smart inside the 
servlet per se.

-Lane



Marc Palmer wrote:

>
> Hi guys,
>
> I'd appreciate it if I could get a bit of input from anybody 
> interested in this webapp I am writing which has the potential (if 
> people agree) to become a core WM project.
>
> The issue I'm currently wrestling with is using a servlet mapping to 
> tie the webapp's servlet to a file type, i.e. 
> <servlet-mapping>*.wmt</servlet- mapping>, so that templates in the 
> webapp root (not WEB-INF) can be returned without referencing the 
> servlet name. i.e. a URI like:
>
> http://yourserver/wmwebapp/mypage.wmt
>
> (wmwebapp is the context path)
>
> Now I'm questioning how useful this is - because I have already 
> implemented, because it is required, URIs of the form:
>
> http://yourserver/wmwebapp/ignition/mypage.wmt
>
> (where ignition is the name of the servlet mapping i.e. /ignition/*)
>
> ...with the difference that in this case the template comes from the 
> normal template location mechanisms - i.e. from the classpath etc.
>
> There is also (nearly implemented) the ability to define "modules" 
> which are segregated mini-apps (each has its own set of actions, 
> helpers, templates etc) which means that you would not need to have 
> all templates on the normal webapp classpath - the plan is that each 
> module can have its own WebMacro.properties and therefore can use 
> explicit template paths / alternative template provider schemes. A 
> page served from a specific module would have a URI like:
>
> http://yourserver/wmwebapp/ignition/mymodule1/mypage.wmt
>
> Anything
> Now, back to the first scenario - templates served from the webapp 
> root - if implemented - will have a couple of problems:
>
> 1. Where do they get their included templates from? A custom template 
> provider could be used to load templates from the context root (not 
> under WEB-INF) if not already supported by WM. It would seem odd to 
> allow pages to be served from the context root but not allow them to 
> be included from that location also.
>
> 2. Having templates in the context/webapp root is a security risk. The 
> nature of this webapp is such that people will likely to a bit more 
> than the usual MVC work in templates and as such sensitive info might 
> be available in templates, and if the web.xml is fouled or the servlet 
> container freaks out, it could return raw template files instead of 
> processing them.
>
> 3. How do I know reliably how the servlet is being called? I need 
> HttpServletRequest.getServletPath() to work so that I can 
> automatically formulate correct URIs from my helper placed into the 
> web context. Using a /ignition/* servlet mapping means this works - 
> getServletPath returns things like "/ignition" and getPathInfo() 
> returns the template requested i.e. "mymodule1/mypage.wmt". However if 
> using a *.wmt servlet mapping, getServletPath returns 
> "mymodule1/mypage.wmt" and getPathInfo returns null! Also 
> getPathInfo() can return null under normal operation (/ignition/* 
> mapping) if there is no template name as part of the URI (not forced 
> by the webapp) - so I am not sure how I can tell whether the servlet 
> was called as a result of a "/ignition/mymodule1" URI or a 
> "/mywebappsubdir/mypage.wmt" URI, both of which would have null PathInfo.
>
> Basically I don't like the way this all feels so I am thinking of not 
> supporting *.wmt mappings of the servlet, and using the module 
> mechanism described throughout. We can of course change the web.xml so 
> that we have slightly nicer URIs - i.e. 
> http://myserver/ignition/execute/mymodule1/mypage.wmt - but even that 
> is somewhat lengthy for me. If I use a /* mapping for the servlet then 
> we stop people being able to efficiently serve resource files like 
> images from the webapp.
>
> I suppose I can call getPathTranslated when using a *.wmt mapping and 
> then call File.exists() on it to see if there is a resource with that 
> name, and if so parse that and return it... and if not then I can try 
> to see if I can pass a valid module out of it - but the same thing 
> applies here... my helper object placed into the templates needs to 
> know the base URI of the servlet (including context path) to produce 
> URIs for the designer without them having to hardcode it. Currently it 
> works like this:
>
> #set $action1 = $Ignition.newAction( "sendEmail")
> #set $action1.ToAddress = "ma...@an..."
> #set $action1.FromAddress = "server@localhost"
> #set $action1.BodyTemplate = "emailtemplate.wmt"
> #set $action2 = $Ignition.newAction( "viewTemplate")
> #set $action2.Template = "thankyouforemail.wmt"
>
> <a href="$Ignition.execute( [$action1, $action2])">Send the email</a>
>
> ...so you never deal with URIs or the syntax needed to munge and 
> namespace the params for each action. Sorry probably very confusing 
> all this because I haven't explained much about the webapp yet...
>
> I am very keen however that it is as easy as possible to return 
> templated pages - I would love it to be as simple as 
> http://myserver/ignition/myshop/mytemplate.wmt but I can't see how I 
> can do that without using a "/*" mapping and all the performance 
> problems with doing that if non-template files are also served from 
> the app.
>
> Maybe I'm being dumb. Any ideas / encouragement welcome :-)
>
>

-- 
Lane Sharman
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