ColdFusion 9 and CFFEED
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I've complained (quite a bit) about some of the warts around the CFFEED tag. Looks like my complaining may have helped a bit. ColdFusion 9 adds a new feature to CFFEED that I think is pretty darn nice.
Previously, if you tried to create a feed and it contained "bad" characters (Microsoft Smart Quotes, etc), then you ended up with invalid XML. Here is a simple example.
First, I'll create a feed with one entry. The entry content is contained in a file called bad.txt:
Here is the code I used to include and create a feed from the text file.
<cfscript> // Create the feed data structure and add the metadata. myStruct = {}; mystruct.link = "http://www.coldfusionjedi.com"; myStruct.title = "My Blog"; mystruct.description = "It wears sunglasses at night"; mystruct.pubDate = Now(); mystruct.version = "rss_2.0";
/* Add the feed items. A more sophisticated application would use dynamic variables and support varying numbers of items. */ myStruct.item =[]; myStruct.item[1] = {}; myStruct.item[1].description = {}; myStruct.item[1].description.value = fileRead(expandPath("../bad.txt")); myStruct.item[1].link = "http://www.cnn.com";
myStruct.item[1].pubDate = Now(); myStruct.item[1].title = "Title";
</cfscript>
<cffeed action = "create" name = "#myStruct#" escapechars="false" xmlVar = "myXML">
<cfoutput> #htmlCodeFormat(myXML)# </cfoutput>
This is standard CFFEED stuff, so I won't describe each line. I don't normally make feeds this way though - normally I create it from a query. Note that I've included escapechars, and set it to false, which makes it match ColdFusion 8 behavior. The result is a bit funky:
Switching escapechars to true though results in:
Nice. There are other ways to handle this but this is certainly a bit simpler.
There is another new ColdFusion 9 that indirectly helps CFFEED as well. One of the things I do at ColdFusionBloggers is called a HTTP Conditional Get. This is basically a 'smart' HTTP call in that I can say: "Hey URL, I last hit you at 5PM, if you haven't updated, send me a nice short message, otherwise send me all your data." This helps streamline some of the network traffic I incur when fetching 500+ RSS feeds. However, there is a problem. If the data is new, and I get the RSS XML back, I have it in a variable. CFFEED only supports parsing URLs and files, it doesn't support parsing a string. This is a bit silly, but, it is what it is.
However - in ColdFusion 9 we now have a RAM based file system called the VFS (Virtual File System). I can use this as a temporary storage for the XML, and point CFFEED at it. Here is a trivial example:
<cfset source = "http://feedproxy.google.com/RaymondCamdensColdfusionBlog"> <cfhttp url="#source#"> <cfset randFileName = "ram:///#createUUID()#.txt"> <cfset fileWrite(randFileName, cfhttp.filecontent)><cffeed action="read" source="#randFileName#" query="feed"> <cfdump var="#feed#" top="1">
<cfset fileDelete(randFileName)>
I begin by grabbing my RSS feed. I want to save it to the VFS and so I just pick a random file for the name. I then point CFFEED at it and convert the RSS into a query. At the end, I clean it up by deleting the file.
Archived Comments
Great idea for the use of the RAM drive.
Thanks Ray.
Thanks Ray, once again you've turned what I thought was going to be a 2 hour job into a 30 minute job!
Thank Adobe - they added it. :)
That's true, let me give credit where credit is due ...
THANK YOU ADOBE for continuing to invest in CF, it has saved me hours of dev time! I keep saying I should learn another language just to have the knowledge and you keep giving me reasons not to.
THANK YOU RAY for the giving us easy examples of how to use these great tools!
Hi Ray
is it somehow possible to write german Umlautes into the meta-Datas like:
mystruct.description = "Nichts ist unmöglich...ColdFusion!";
thanx in Adv.
This may be a dumb question, but did you try?
Have you published an example of creating an RSS feed in CFScript? I notice that this example drops out of CFScript to create the feed...
Nope. It was added in CF901 actually (I wrote the CFC ;). It's pretty trivial though. Take your query and pass it to the feed CFC instance. Need one? (A full example I mean.)
I worked it out. I'll be posting my own example soonish.
I've posted an example on my blog at http://www.brilang.com/2012...
This example combines an RSS feed with a MySQL database query to create a combined RSS feed. The example is in 100% pure CFScript.