Reference fields (#3267)

* Adds a configurable 'reference pattern' to the IndexingReferenceMixin class

* Expand tests for reference_pattern validator:

- Prevent inclusion of illegal characters
- Prevent multiple groups of hash (#) characters
- Add unit tests

* Validator now checks for valid strftime formatter

* Adds build order reference pattern

* Adds function for creating a valid regex from the supplied pattern

- More unit tests
- Use it to validate BuildOrder reference field

* Refactoring the whole thing again - try using python string.format

* remove datetime-matcher from requirements.txt

* Add some more formatting helper functions

- Construct a regular expression from a format string
- Extract named values from a string, based on a format string

* Fix validator for build order reference field

* Adding unit tests for the new format string functionality

* Adds validation for reference fields

* Require the 'ref' format key as part of a valid reference pattern

* Extend format extraction to allow specification of integer groups

* Remove unused import

* Fix requirements

* Add method for generating the 'next' reference field for a model

* Fix function for generating next BuildOrder reference value

- A function is required as class methods cannot be used
- Simply wraps the existing class method

* Remove BUILDORDER_REFERENCE_REGEX setting

* Add unit test for build order reference field validation

* Adds unit testing for extracting integer values from a reference field

* Fix bugs from previous commit

* Add unit test for generation of default build order reference

* Add data migration for BuildOrder model

- Update reference field with old prefix
- Construct new pattern based on old prefix

* Adds unit test for data migration

- Check that the BuildOrder reference field is updated as expected

* Remove 'BUILDORDER_REFERENCE_PREFIX' setting

* Adds new setting for SalesOrder reference pattern

* Update method by which next reference value is generated

* Improved error handling in api_tester code

* Improve automated generation of order reference fields

- Handle potential errors
- Return previous reference if something goes wrong

* SalesOrder reference has now been updated also

- New reference pattern setting
- Updated default and validator for reference field
- Updated serializer and API
- Added unit tests

* Migrate the "PurchaseOrder" reference field to the new system

* Data migration for SalesOrder and PurchaseOrder reference fields

* Remove PURCHASEORDER_REFERENCE_PREFIX

* Remove references to SALESORDER_REFERENCE_PREFIX

* Re-add maximum value validation

* Bug fixes

* Improve algorithm for generating new reference

- Handle case where most recent reference does not conform to the reference pattern

* Fixes for 'order' unit tests

* Unit test fixes for order app

* More unit test fixes

* More unit test fixing

* Revert behaviour for "extract_int" clipping function

* Unit test value fix

* Prevent build order notification if we are importing records

InvenTree/templates/js/translated/build.js

@@ -4,7 +4,6 @@
 /* globals
     buildStatusDisplay,
     constructForm,
-    global_settings,
     imageHoverIcon,
     inventreeGet,
     launchModalForm,
@@ -36,7 +35,7 @@
 function buildFormFields() {
     return {
         reference: {
-            prefix: global_settings.BUILDORDER_REFERENCE_PREFIX,
+            icon: 'fa-hashtag',
         },
         part: {
             filters: {
@@ -731,9 +730,8 @@ function loadBuildOrderAllocationTable(table, options={}) {
                 switchable: false,
                 title: '{% trans "Build Order" %}',
                 formatter: function(value, row) {
-                    var prefix = global_settings.BUILDORDER_REFERENCE_PREFIX;
 
-                    var ref = `${prefix}${row.build_detail.reference}`;
+                    var ref = `${row.build_detail.reference}`;
 
                     return renderLink(ref, `/build/${row.build}/`);
                 }
@@ -2372,7 +2370,6 @@ function loadBuildTable(table, options) {
             filters,
             {
                 success: function(response) {
-                    var prefix = global_settings.BUILDORDER_REFERENCE_PREFIX;
 
                     for (var idx = 0; idx < response.length; idx++) {
 
@@ -2386,7 +2383,7 @@ function loadBuildTable(table, options) {
                             date = order.target_date;
                         }
 
-                        var title = `${prefix}${order.reference}`;
+                        var title = `${order.reference}`;
 
                         var color = '#4c68f5';
 
@@ -2460,12 +2457,6 @@ function loadBuildTable(table, options) {
                 switchable: true,
                 formatter: function(value, row) {
 
-                    var prefix = global_settings.BUILDORDER_REFERENCE_PREFIX;
-
-                    if (prefix) {
-                        value = `${prefix}${value}`;
-                    }
-
                     var html = renderLink(value, '/build/' + row.pk + '/');
 
                     if (row.overdue) {