Variable: servlet (See also: Javadoc page)

For example, to get the file system root of your web application you can do the following:

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1 def root = servlet.getRealPath("/")

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Variable: faces (See also: Javadoc page)

To force the current view to be rendered, you could do the following:

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1 faces.renderResponse()

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Variable: el (See also: Javadoc page)

To force el resolution on an object you could call the following:

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1 el.getValue(elCtx, someObject, "someProperty")

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Variable: ef (See also: Javadoc page)

To create a value expression object you could call the following:

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1 ef.createValueExpression(elCtx, "#{someExpression}", Object.class)

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Variable: elCtx (See also: Javadoc page)

To get the current variable mapper:

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1 def vm = elCtx.variableMapper

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Variable: viewId

This can be helpful for debugging or other purposes where you need to know what the view id is:

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1 log.info("Current view: $viewId")

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Variable: path

This can be helpful when needing information about the file system location of the current view:

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1 println "Current source for this view:"  2 print new File(path).text

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Variable: parentPath

If you need to access files based off where your current view is located, this can be helpful. For instance if you wanted to access some xml file next to the view you could do this:

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1 def xml = parentPath."someFile.xml".text

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Variable: servletRoot

If you need to access files based off where your web application is located, this can be helpful. For instance if you wanted to access some xml off a certain directory in your web app:

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1 def xml = servletRoot."WEB-INF".conf."someFile.xml".text

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Variable: actionURL

When you need to post back and maybe want to write your own forms you can easily get the post back url with this variable (this can be especially helpful when writing library components, in particular form renderers):

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1 xh.form(action: actionURL, method: "post") { ... }

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Variable: external (See also: Javadoc page)

If you don't want to deal directly with the servlet implementation, you can use the faces external context object available via this variable. For example, you could get remote user info by using the following:

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1 print { "Current remote user: $external.remoteUser" }

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Variable: request

This can be used to access the servlet request object directly (the same as external.request). For example, to get the request headers you could do this:

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1 request.headerNames.each { println "$it: " + request.getHeader(it); }

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Variable: response

This can be used to access the servlet response object directly (the same as external.response). For example, to add a response header you could do this:

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1 response.addHeader("Pragma", "no-cache")

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Variable: param

This can be used to access posted variables for the current request. On some pages you may prefer to use only use get's together with passed parameters, maybe to show some document, you could do this:

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1 def data = someController.getDocument(Integer.parseInt(param['id'])).data

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Variable: paramNames

This can be used to access posted variables names for the current request. To loop through the posted variable names you could do the following:

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1 paramNames.each { par -> print par + "=" + param[par] }

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Variable: varCtx

When a local variable interferes with something in the variable context, or even if one of the above variables does, you can force variable context resolution by using this variable. The following would assign the context variable 'myLocalVar' to the value variable instead of getting the local variable:

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1 def myLocalVar = 100  2 def value = varCtx.myLocalVar

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Variable: headers

You can easily debug the request headers with this variable:

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1   2 headers.each { header ->  3     println "Header: $header.key"  4     header.value.each { println "Value: $it" }  5 }  6

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Variable: cookies

You can easily check for the existence of a cookie with this variable:

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1   2 if (!cookies.myCompanyCookie) {  3     response.addCookie("myCompanyCookie", "someValue")  4 }  5

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Variable: useragent

You can check/anaylize the User-Agent (browser) by simply referencing this variable:

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1   2 if (useragent =~ /MSIE/) {  3     ...  4 }  5

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Variable: *Context

You can force access to set/get a variable in a particular scope. The available scopes depend on the framework you are using (etc, Seam, Spring). Gracelets comes with a set of default scopes (view, request, conversation (default), session, application) that you can use. So for instance if you wanted to hold state in a variable in the current view context, you could make sure it is stored in that scope by doing the following:

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1 viewContext.someVar = 'someValue'