Localize error messages

[palagdan]

Resolves partially #550

[palagdan]

@blcham
I can't localize all the errors from the backend because many errors are dynamically generated. So, I replaced only errors with plain text, that does not contains some value from the backend.

[blcham]

@palagdan @kostobog What do you think about the following? (

I see a lot of duplicate text, so I am thinking if it is not better to have some .error.genericError as a template (using i18next nesting -- https://www.i18next.com/translation-function/nesting):

{
  "error": {
    "default": "Došlo k chybě",
    "genericError": "Nepodařilo se {{action}} {{object}}. {{error}}",
    "faultEvent": {
      "findAll": "{{t('error.genericError', { action: 'najít', object: 'události závad' })}}",
      "update": "{{t('error.genericError', { action: 'aktualizovat', object: 'událost závady' })}}",
      "remove": "{{t('error.genericError', { action: 'odstranit', object: 'událost závady' })}}",
      "create": "{{t('error.genericError', { action: 'vytvořit', object: 'událost závady' })}}",
      "updateRectangle": "{{t('error.genericError', { action: 'aktualizovat', object: 'obdélník' })}}",
      "getFailureMode": "{{t('error.genericError', { action: 'načíst', object: 'režim selhání události' })}}",
      "deleteFailureMode": "{{t('error.genericError', { action: 'smazat', object: 'režim selhání události' })}}",
      "updateChildrenSequence": "{{t('error.genericError', { action: 'aktualizovat', object: 'pořadí dětí' })}}",
      "getRootReusable": "{{t('error.genericError', { action: 'najít', object: 'znovu použitelné události závady' })}}",
      "getAllReusable": "{{t('error.genericError', { action: 'najít', object: 'všechny znovu použitelné události závady' })}}"
    },
    "faultTree": {
      "rootEvent": {
        "deleteViolation": "Kořenová událost stromu nemůže být smazána!"
      },
      "intermediateEventAsLeaf": "Mezilehlá událost nemůže být na konci cesty!",
      "findAll": "{{t('error.genericError', { action: 'načíst', object: 'stromy závad' })}}",
      "findAllWithFilters": "{{t('error.genericError', { action: 'načíst', object: 'stromy závad s filtry' })}}",
      "find": "{{t('error.genericError', { action: 'najít', object: 'strom závad' })}}",
      "create": "{{t('error.genericError', { action: 'vytvořit', object: 'strom závad' })}}",
      "update": "{{t('error.genericError', { action: 'aktualizovat', object: 'strom závad' })}}",
      "remove": "{{t('error.genericError', { action: 'odstranit', object: 'strom závad' })}}",
      "getTreePaths": "{{t('error.genericError', { action: 'načíst', object: 'cesty stromu' })}}",
      "getTreePathsAggregate": "{{t('error.genericError', { action: 'načíst', object: 'všechny cesty stromu' })}}",
      "calculateCutSets": "{{t('error.genericError', { action: 'vypočítat', object: 'řezové množiny stromu závad' })}}"
    },

or having

2. or having just a generic entity error

{
  "error": {
    "default": "Došlo k chybě",
    "entity": {
      "findAll": "Nepodařilo se načíst {{entity}}. {{error}}",
      "find": "Nepodařilo se najít {{entity}}. {{error}}",
      "create": "Nepodařilo se vytvořit {{entity}}. {{error}}",
      "update": "Nepodařilo se aktualizovat {{entity}}. {{error}}",
      "remove": "Nepodařilo se odstranit {{entity}}. {{error}}"
    },

[kostobog]

@blcham
When we optimize the text there will be grammar issues and it will be harder to maintain by translators.
Variant 2 is nice as it is compact but we should consider that it will be needed to refactor error codes for generic entity errors and also introduce a entity type argument in responseUtis.handleServerError.

[blcham]

ad 1)

When we optimize the text there will be grammar issues and it will be harder to maintain by translators.

I was not able to find any grammar issue although i do not like it much either.

ad 2)

we can discuss on the meeting.

[palagdan]

@blcham

I wanted to discuss one more thing. How should we handle dynamic exception messages like the following with messageId:

public class EntityNotFoundException extends FtaFmeaException {

    public EntityNotFoundException(String message) {
        super(message);
    }

    public static EntityNotFoundException create(String resourceName, Object identifier) {
        return new EntityNotFoundException(resourceName + " identified by " + identifier + " not found.");
    }

}

[kostobog]

@palagdan @blcham
Idea for question in comment
The server can send the arguments for a parametrized error message. For example:

public class ErrorInfo {
    private String message;
    private String messageId;
    private Map<String, String> messageArguments;
    private String requestUri;
}

For the example above, consider that server sends messageArguments as follows:

{ 
  resourceName: "Component"
  identifier: "component-id"
}

Message template can be declared as follows
"errorId": " {{resourceName}} identified by {{identifier}} not found."

And specific message can be constructed as:
t(data.messageId, data.messageArguments)

[palagdan]

@blcham

Thanks for the tip @kostobog regarding the arguments! I've implemented it on the backend—could you take a look? I've tested these errors, and now they are localized in Czech too: