Skip a component based on condition in Talend - talend

Question

I have a scenario where I would like to skip a component to execute based on the condition and run its consecutive components in Talend.
Is it at all possible?

Answer 1

You have two options available to you for conditionally executing parts of your job.
Where the component that follows your conditional check can be a starting component (if you drop it to the canvas then it should have a green background) then you can use the Run if connector to link it to the previous part of your job like so:
In this example we simply call another tJava component conditionally but this could be any component that is startable.
Where the first tJava component (Set condition boolean) is configured with the following code:
Boolean condition = false;
globalMap.put("condition",condition);
And the two Run if connectors are set as ((Boolean)globalMap.get("condition")) == true and ((Boolean)globalMap.get("condition")) == false respectively.
A better option may be to use the filtering in a tMap or tFilterRow component and this also allows you to link to components that aren't starting components. To do this you would set your job up as below:
In this job I have hard coded some tabular data in a tFixedFlowInput component:
We then use a tMap to filter the flows of data to any following components:
In which we test the value of the boolean condition column of our data. As an illustration I have also applied some simple, conditional transformation to the data where "true" rows have 1000 added to their value and "false" rows have 100 subtracted from their value.
From here you can then carry on the flow of your job as normal, in this case we link to a tSystem component to execute system commands as per your comment.

Answer 2

I've mocked up a job for you:
I have a context variable called: startFrom
It can be accessed with context.startFrom
I've placed a tJava with a few tWarns:
I use 4 context settings:
Default
Normal
Opt
two
So my Job:
Does nothing
Start from "Start"
Start from "Optional_Start"
Start from "RecoverFromHere"
If settings are the following:
context.startFrom.equals("opt")
Recovery and Recovery1 prints out their names using System.out
If I start my job I can select where I want to start it. If I don't select anything: context value is null, it won't do anything.

Answer 3

you can not use prejob as it does not have runif trigger, but you can do like this
prejob -->oncomponentok-->tJava (in here you poupulate you evaluate your condition say as given below)---->RUN IF Trigger - you put your condition here..((String)globalMap.get("var_myCondition")).equals("true") --->component to run in true condition
--->RUN IF Trigger on (tJava) ---((String)globalMap.get("var_myCondition")).equals("false")--->component to run in false condition
in short your job would be like
prejob-->tJava---(RUNIF TRIGGER)------>component/flow to run in true condition
---(RUNIF TRIGGER)------>component/flow to run in false condition
tJava code
String myCondition="false";
globalMap.put("var_myCondition",myCondition);