Fixes issue #65

[reynoldtan]

This PR fixes Issue #65 - Unable to modify instance.

The error is caused by hook_validate when modifying an instance where there is another instance and both share the same organism. This fix takes into account sequence assembly information before checking for identical instance.

To test:
// No two instances share same organism and empty sequence assembly

1. Create an instance and set organism to X and sequence assembly field to empty.
2. Create a similar instance to step 1, except set organism different to X so that when you modify this (step 2 instance) and set organism to match X (step 1 instance) it should trigger the validation.

// No two instances share same organism and same sequence assembly

1. Find an instance and note organism and sequence assembly.
2. Create a new instance, set the organism other than the organism in step 1 (as noted) and sequence assembly to be the same in step 1.
3. Modify instance in step 2 and change the organism to match the organism in step 1. This should trigger the validation, an existing instance matched the organism and sequence assembly information.

Knowing what triggers validation, test fields organism, description, start location and tracks to display as well.

[dsenalik]

There is a pull request that is a fix for your tests failing, see

tripal/tripal#1237

tripal/tripal#1249

[laceysanderson]

✅ Code looks good

The validation is good too and testing worked as expected :-)

Only one thing to fix. Right now it disables the analysis form field on edit even it is not yet. Admin should be able to go back and add analysis after the initial creation. This is common if the first time they didn't bother because it was the only assembly or the functionality didn't exist yet, but now there are many assemblies and they want to make it more clear.

[reynoldtan]

The latest commit fixes the issue of field sequence assembly set to disabled by default, and as part of the fix, it will now save value set to this field when saving modifications.

Please note that with this fix, the edit form will only allow modification of sequence assembly when it was not set previously in create/add form.

To test:

1. Create an instance and leave sequence assembly field empty.
2. Modify this instance, and set a value for sequence assembly field.
3. Click save. Validation rules in the previous commit still apply.

[laceysanderson]

Looks good and works perfectly -Thank you @reynoldtan