Adding sum-array helper

This helper sums up numeric values together, for example to get a combined duration value of selected entries use:

CODE

{{sum-array model "Duration" "formatMsToDuration"}}

where,

sum-array is the name of the helper itself ("fixed").
model is the model containing selected entries ("fixed").
Duration is the metadata binding name, please see available bindings ("configurable").
formalMsToDuration is the converter name which converts the result into HH:MM:SS:xxx format ("configurable").

Another example would be to calculate total FileSize of selected entries.

CODE

{{sum-array model "FileSize" "formatFileSize"}}

Here,

FileSize is the metadata binding name.
formatFileSize is the helper that converts the result into appropriate unit e.g KB, MB, GB etc.

Example Configuration

CODE

{{#form-container legacyController=legacyController}}
	{{#responsive-grid-area}}
        <div data-col="sm-4 xs-12 valign-sm-center valign-xs-bottom">
			Total Size:
		</div>
        <div data-col="sm-8 xs-12 valign-center">
			{{sum-array model "FileSize" "formatFileSize"}}
		</div>

        <div data-col="sm-4 xs-12 valign-sm-center valign-xs-bottom">
			Total Duration:
		</div>
        <div data-col="sm-8 xs-12 valign-center">
			{{sum-array model "Duration" "formatMsToDuration"}}
		</div>
    {{/responsive-grid-area}}
{{/form-container}}