SWITCH Task development

Switch task workflow step as follows

User-defined expressions and branch information are stored in taskParams in taskdefinition. When the switch is executed, it will be formatted as SwitchParameters
SwitchTaskExecThread processes the expressions defined in switch from top to bottom, obtains the value of the variable from varPool, and parses the expression through javascript. If the expression returns true, stop checking and record The order of the expression, here we record as resultConditionLocation. The task of SwitchTaskExecThread is over
After the switch task runs, if there is no error (more commonly, the user-defined expression is out of specification or there is a problem with the parameter name), then MasterExecThread.submitPostNode will obtain the downstream node of the DAG to continue execution.
If it is found in DagHelper.parsePostNodes that the current node (the node that has just completed the work) is a switch node, the resultConditionLocation will be obtained, and all branches except resultConditionLocation in the SwitchParameters will be skipped. In this way, only the branches that need to be executed are left