Sagar Ganatra's Blog

I was working on creating a CRUD application with REST and wanted to retrieve records with a GET request. The GET request would contain the ARTID for which the record has to be retrieved in the URL itself. To do this I had added an argument to the method implementing the GET request with ‘restargsource’ attribute set to path. The URL would be of the form: http://localhost:8500/rest/restapp/artService/getart/1 However, in another scenario I wanted to retrieve all the records from the ART table when there is no ARTID specified in the URI i.e. with the URL: http://localhost:8500/rest/restapp/artService/getart/ PathParams are always required and if they’re not specified then a ‘404 Not found’ error would be thrown. I thought of adding another method to handle this GET request with no PathParams. But, it would have made my code look clumsy and semantically not correct. However, I was able resolve this by providing a regular expression for the PathParam argument.

A quick post on the new function arraySlice added to the list of functions in ColdFusion 10. The arraySlice function is used to  select a part of the array. It takes three arguments – array, offset and length.

In ColdFusion 10, one can restrict the type of file being uploaded to the server when using CFFILE to upload the files. The new attribute accept allows the user to specify various MIME types or extensions of the file that can be accepted by the server. If the user tries to upload a file with a .txt extension but it contains xml data (application/xml MIME type) then the server would accept or throw an exception based on the value specified for the strict attribute. 'strict' is a boolean attribute added to the CFFILE tag. By default it is true and therefore wouldn't allow the user to upload a file whose contents are of different MIME type. When the strict attribute is set to false it would allow the user to upload a file irrespective of its content. However, an error would be thrown if the extension of the file doesn't match the ones specified in the accept attribute.

There are a couple of variables that have been introduced in Application.cfc which are REST specific. These are this.restsettings.cfclocation and this.restsettings.skipCFCWithError . If you have a list of directories containing REST enabled CFCs then you can specify the same in the variable this.restsettings.cfclocation. At the time of registration, the specified directories and its subdirectories will be scanned for REST enabled CFCs and then deployed. If any of these CFCs contain compilation errors then an error is thrown and the registration would fail. To tackle this another variable this.restsettings.skipCFCWithError is provided. When set to true, the CFCs with compilation errors would be skipped. Only those without any compilation errors would be deployed successfully.

Today, I wrote a post on the new lifecycle method - ‘onAbort’, which can be defined in an Applicaiton.cfc file . It is invoked when the cfabort tag is executed. David Boyer , asked me whether the onRequestEnd method is also invoked on executing the cfabort tag. In CF 9.0.1 it did invoke the onRequestEnd method. See Ben’s post: http://www.bennadel.com/blog/2221-CFAbort-And-OnRequestEnd-Behavior-In-ColdFusion-8-And-ColdFusion-9.htm Now in CF 10, this behavior has changed. The onRequestEnd method is no longer invoked when cfabort, cflocation or cfcontent tag is executed. The onAbort handler method defined in Application.cfc file would be invoked on executing these tags. Also, the onRequestEnd method would not be invoked even if the abort handler(onAbort) is not defined in Application.cfc.

I was experimenting with a new method 'onAbort' introduced in ColdFuion 10 which can be defined in an Application.cfc file. This method is invoked when cfabort is called. What if showerror attribute is also present in the cfabort tag? Would it still invoke the onAbort method and then onError? The onAbort method would be ignored and the onError method would be invoked. Even in a case wherein the onError method is not defined in Application.cfc, the onAbort method wouldn't be invoked. In this case the error message would be shown on the standard error template.

There are various complex types in ColdFusion – Array, Struct, Query. When a REST service in ColdFusion returns one of these complex types, it has to be serialized to either JSON or XML format. As explained in my previous post , the HTTP protocol can be used in content type negotiation. You can specify the desired content type either by specifying it at the end of the URL or in the Accept header of HTTP request. In this post, I’ll explain the format in which the complex types are returned from a ColdFusion REST service.