Custom Identifier name isn't allowed to be custom.

[shehi]

Bug Report

Q	A
BC Break	no idea
Version	2.0.1

Summary

In XML configuration, attempting to give custom field_name to IDs doesn't work. ClassMetadata fails.
<id field-name="uuid" strategy="UUID" type="bin_uuid" />

Current behavior

<id field-name="uuid" strategy="UUID" type="bin_uuid" />

Field-names both in document class, and in Db are is "uuid". Yet, code here:
https://github.com/doctrine/mongodb-odm/blob/master/lib/Doctrine/ODM/MongoDB/Mapping/ClassMetadata.php#L1953
resolves $mapping['fieldName'] value to id instead of intended uuid.

How to reproduce

Use this as ID field configuration in your XML document odm file:
<id field-name="uuid" strategy="UUID" type="bin_uuid" />

Expected behavior

For ClassMetadata to have $mapping['fieldName'] to actually be equal to $mapping['field_name'] (the latter having the correct value), being equal to uuid not id, as this example expects.

UPDATE: We can't have custom identifier name in Db, it is always _id. This was realized to be the case and the fact established in our chat below.

[shehi]

At https://github.com/doctrine/mongodb-odm/blob/master/lib/Doctrine/ODM/MongoDB/Mapping/ClassMetadata.php#L1953 the dumped value of $mapping variable is as below:

array(15) {
  'id' =>
  bool(true)
  'fieldName' =>
  string(2) "id"
  'field-name' =>
  string(4) "uuid"
  'strategy' =>
  string(4) "UUID"
  'type' =>
  string(8) "bin_uuid"
  'options' =>
  array(0) {
  }
  'name' =>
  string(3) "_id"
  'isCascadeRemove' =>
  bool(false)
  'isCascadePersist' =>
  bool(false)
  'isCascadeRefresh' =>
  bool(false)
  'isCascadeMerge' =>
  bool(false)
  'isCascadeDetach' =>
  bool(false)
  'nullable' =>
  bool(false)
  'isOwningSide' =>
  bool(true)
  'isInverseSide' =>
  bool(false)
}

[malarzm]

Field-names both in document class, and in Db are "uuid".

IIRC field named uuid cannot be an identifier in the document as MongoDB expects document's identifier to be named _id and that's pretty much hardcoded in the db itself. I think we should rather block custom name for identifier fields.

[shehi]

After some research, I tend to agree with you @malarzm . I think this issue should be renamed appropriately into a task to disable custom fieldnames for IDs.

[alcaeus]

Identifier names in the database are fixed to the _id field - this is the identifier of a MongoDB document. There is a bug with handling the field-name attribute in XML mappings, which allows you to change the name of the class property the database field is mapped to. This bug is being fixed in #2097.

In your case, you can have a uuid field in the class and map it to the _id field by using the <id field-name="uuid" type="uuid" /> mapping. If you want to store this in a uuid field, then it is no longer an identifier.

[shehi]

@alcaeus , that IS the problem: I can't have field named $uuid in document class. It is being converted to $id. That might need fixing.

[shehi]

@alcaeus , I just checked your PR, and I believe change in XMLDriver is fixing the problem I described above.

[alcaeus]

I just wanted to make sure you don't have wrong expectations because of this:

Field-names both in document class, and in Db are "uuid".

With the id mapping you described, the database field will always be _id - the field-name attribute only affects the class property. If that's what you intended to do, I apologise for the confusion I caused.

[shehi]

Yea, updated the original post above, striking through some wordings. So yea, current expectation is the fix in document class.