Pre-upgrade Check Version Specification Debate

Summary of what's been discussed.

Proposal #1) Original

The original requested way that it should work is illustrated in this example:

<compatibility>
  <version>1.5</version>
  <version>2.5</version>
  <version>3.0.1</version>
  <version>4</version>
<compatibility>

Is interpretted as:

• Joomla 1.5: compatible
• Joomla 1.6: not compatible
• Joomla 1.7: not compatible
• Joomla 2.5: compatible
• Joomla 3.0: compatible for 3.0.1 and up in the 3.0 version
• Joomla 3.1: not compatible
• Joomla 3.2: not compatible
• Joomla 3.5: not compatible
• Joomla 4:0: compatible
• Joomla 4.1: compatible
• Joomla 4.2: compatible
• Joomla 4.5: compatible

Accidentally coded as

<compatibility>
  <version>1.5</version>
  <version>2.5</version>
  <version>3.0.1</version>
  <version>4</version>
<compatibility>

Is interpretted as:

• Joomla 1.5: compatible
• Joomla 1.6: not compatible
• Joomla 1.7: not compatible
• Joomla 2.5: compatible
• Joomla 3.0: compatible only for 3.0.1
• Joomla 3.1: not compatible
• Joomla 3.2: not compatible
• Joomla 3.5: not compatible
• Joomla 4:0: compatible
• Joomla 4.1: compatible
• Joomla 4.2: compatible
• Joomla 4.5: compatible

The above was changed to the original specifications, but some people continued to argue whether "3.0.1" should mean "compatible for 3.0.1 through 3.0.x" or "only for 3.0.1".

Proposal #2) Composer

Others thought, we shouldn't use either of the above, but should use: Composer

Proposal #3) Remove version attribute and replace it with compatibility tag (in the below manner)

See: https://github.com/joomla/joomla-cms/issues/594

Proposal #4) Modification of Original (compare with #1) after adding an exclude attribute/parameter

After adding an exclude attribute/parameter, the proposal became:

<compatibility>
  <version>3.5</version>
  <version>4.2.2</version>
  <version>6</version>
  <version exclude_only="true">6.1.3</version>
  <version>7</version>
  <version exclude_only="true">7.0</version>
  <version exclude_only="true">8</version>
<compatibility>

is interpreted as:

• Joomla 3.0: not compatible
• Joomla 3.1: not compatible
• Joomla 3.2: not compatible
• Joomla 3.5: compatible

• Joomla 4.0: not compatible
• Joomla 4.1: not compatible
• Joomla 4.2: compatible from 4.2.2 and up
• Joomla 4.5: compatible

• Joomla 5.0: not compatible
• Joomla 5.1: not compatible
• Joomla 5.2: not compatible
• Joomla 5.5: not compatible

• Joomla 6.0: compatible
• Joomla 6.1: compatible for all (above and below) except 6.1.3
• Joomla 6.2: compatible
• Joomla 6.5: compatible

• Joomla 7.0: not compatible
• Joomla 7.1: compatible
• Joomla 7.2: compatible
• Joomla 7.5: compatible

• Joomla 8.0: not compatible
• Joomla 8.1: not compatible
• Joomla 8.2: not compatible
• Joomla 8.5: not compatible

Notes

99%-100% of the code is written for the original implementation. The getcomposer approach is not written.

The original implementation did not ask for a x.y.z version to be able to be excluded. If a feature like that is needed, e.g. <not_version>3.0.7</not_version>, it can be implemented.