Customizing the File Reader

This is good example how we can Eliminate bottlenecks with IguanaX. This is the problem. A large lab needs to have a file reading component which can feed files from different customers based on prefix of the file, i.e. some files start with JJ333, others XYZ etc. depending on the source.

How can we make a super streamlined component which:

Matches the requirements
Is easy to implement
Simplifies operations

Let’s do it!

Import a custom version of the file reader from git@bitbucket.org:interfaceware/file_tutorial.git

Create component from Git URL - leave the component as Editable

Copy paste the URL from here:

git@bitbucket.org:interfaceware/file_tutorial.git

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

Open the component in the translator with the customize link

See Customizing components to see how done if you have not done this before.

Build a custom configuration

See Custom Fields - We can add ClientList which will be a comma delimited list of the prefixes we want to filter on:

We need to modify the matching algorithm - what do we start with?

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

https://bitbucket.org/interfaceware/fromfile/src/main/MatchRules.lua

function MatchFile(FileName)
   return true
end

Let's extract the filename so we can look at it:

Change the matching to add in two lines:

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

Start the new MatchFile logic with getting the list of prefixes and removing white space

We’ll apply /wiki/spaces/IXB/pages/3181903910 and write this as a function:

function APPidList()
   local IdList = component.fields()["ClientList"]
   IdList = IdList:split(",")
   for i = 1, #IdList do
      IdList[i] = IdList[i]:trimWS()
   end
   return IdList
end

function MatchFile(FileName)
   local IdList = APPidList();
   return true
end

These are the concepts we have used:

Writing a function
Using APP as a prefix, see Using prefixes for naming code
Custom Fields
String:split()
Iterating through a Lua table as list
Trimming white space

Make a function which takes the ID and sees if the filename starts with it

So now we make a function to determine if the file name matches

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

Concepts used:

Now put all the matching logic together

We write the new MatchFile function based on the functions we have written already:

function MatchFile(FileName)
   local IdList = APPidList()
   local JustFileName = FILfilename(FileName)
   for i = 1, #IdList do
      if APPmatchPrefix(IdList[i], JustFileName) then 
         return true;
      end
   end
end

Concepts used:

A function
FIL Library used to get the file name
For loop with Lua table as list using # Operator on Lua Tables
if statements

Commit your changes, alter the component to run on the new commit and run it!

Commit and Push Changes to Git and go to the component card for Choosing the code to run for your component.