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This component generates some test files to make it easier to learn how to make a custom file reader.

You can useCreate component +FROM URL to import the component.

Copy paste the URL from here:

git@bitbucket.org:interfaceware/file_tutorial.git

Refer to Customizing components Edit a Component to see how it's done if you have not done this before.

Navigate to MatchRules.lua in the Project Tree. This is the function we need to alter:

function MatchFile(FileName)
   return true
end

The file reader component is deliberately simple and uses /wiki/spaces/IXB/pages/3181903910 separation of concerns to make it more obvious how to modify the code to meet new needs. We need this function to return true when the matching criteria are met.

Change the matching to add in two lines so we can see the filenames we need to filter on.

function MatchFile(FileName)
   local JustFileName = FILfilename(FileName)
   trace(JustFileName)
   return true
end

These are the concepts we have used:

• A function

• FIL Library used to get the file name

• Using trace() function

Create a second function, APPidList, to extract the ClientList prefixes from the custom fields and update MatchFile to call APPidList.

You can replace the contents of the MatchRules.lua file with this new code:

function APPidList()
   local IdList = component.fields()["ClientList"]
   return IdList
end

function MatchFile(FileName)
   local IdList = APPidList()
   trace(IdList)
   local JustFileName = FILfilename(FileName)
   trace(JustFileName)
   return true
end

Concepts used:

• /wiki/spaces/IXB/pages/3181903910

• Writing a function

• Using trace() function

• Using APP as a prefix, see Using prefixes for naming code to maintain a common naming convention

• Custom Fields

Create a third function, APPmatchPrefix, to determine if the filename matches the prefix. You can copy the code below:

function APPmatchPrefix(Prefix, FileName)
   local Part = FileName:sub(1, #Prefix)
   trace(Part, Prefix)
   return (Part == Prefix)
end

See the screenshot below and add a line to MatchFile to call and invoke AppmatchPrefix.

Concepts used:

• A function

• https://interfaceware.atlassian.net/wiki/spaces/IXB/pages/2684813341/Operator+on+# Operator on Strings to get the length of the prefix

• String:sub()

• Equality and inequality operators