[WIP] Automate Expression Methods

[mkanoor]

Adding support for Expression Methods

Expression Methods allow you to use Advance Search Filters as Automate Methods, substituting the user_input from Automate Objects. The advantages of this approach is that the methods run directly in the worker and don't have the overhead of forking a DRb process to run the Automate Methods.

1. Create an expression using the ManageIQ Explorer and any values that need to be set at runtime from automate, mark then as user input. These are positional arguments.
2. Save the expression e.g if my_search (user_admin_my_search)
3. Create a new Automate Method and set the method location to expression
4. In the data field for the method set the expression name (user_admin_my_search)
5. In the Input Arugments create arg1,arg2,arg3... for each of the user input fields from Step 1
6. Create a field called attributes with the list of attributes that you would like to collect from the search objects. e.g (name, id)

Inputs Arguments

• arg1 The first argument in the expression
• arg2 The second argument in the expression
• arg n The nth argument in the expression
• attributes A comma delimited list of attributes to select from the resultant objects
  or
• distinct A comma delimited list of attributes which are distinct in the resultant objects

Optional arguments

• result_obj The object where the result data should be stored (default: current object)
• result_attr The name of the attribute which stores the result (default: method_result)
• result_type The result type hash or array (default: hash)
• on_empty The method behavior when the search returns an empty list
  warn | error | abort
• default The default value in case the result is empty and you select warn

After the method ends
$evm.root['ae_result'] = 'ok' | 'error' | 'warn'

[mkanoor]

Create an expression and save it.

Method Location is set as expression
Method Data has the name of the expression
Input Parameters contain substitution from the inbound object

The results of the query go into an attribute called method_result as an array

[miq-bot]

<pr_mergeability_checker />This pull request is not mergeable. Please rebase and repush.

[miq-bot]

<pr_mergeability_checker />This pull request is not mergeable. Please rebase and repush.

[miq-bot]

<pr_mergeability_checker />This pull request is not mergeable. Please rebase and repush.

[miq-bot]

Checked commits mkanoor/manageiq@3cfdab4~...a01abdd with ruby 2.2.5, rubocop 0.37.2, and haml-lint 0.16.1
14 files checked, 5 offenses detected

app/controllers/application_controller/filter.rb

• ❗ - Line 984, Col 52 - Style/ExtraSpacing - Unnecessary spacing detected.

app/controllers/miq_ae_class_controller.rb

• ❕ - Line 923, Col 121 - Metrics/LineLength - Line is too long. [134/120]

lib/miq_automation_engine/engine/miq_ae_expression_method.rb

• ❕ - Line 133, Col 121 - Metrics/LineLength - Line is too long. [124/120]
• ❕ - Line 2, Col 3 - Metrics/ClassLength - Class has too many lines. [125/100]

spec/lib/miq_automation_engine/miq_ae_expression_method_spec.rb

• ❗ - Line 1, Col 1 - Metrics/ModuleLength - Module has too many lines. [170/100]

[miq-bot]

<pr_mergeability_checker />This pull request is not mergeable. Please rebase and repush.

[gmcculloug]

Replaced by:
Added support for expression methods (#15537)
Expression method UI changes (ManageIQ/manageiq-ui-classic#1668)
Support for expression methods (ManageIQ/manageiq-automation_engine#49)
Export Import of Expression Methods (ManageIQ/manageiq-automation_engine#50)