# latest-strategies

Tag: latest-strategies

Defines a list of latest strategies usable in Ivy. Each latest strategy is identified by its name, given as an attribute.

The child tag used for the latest strategy must be equal to a name of a latest strategy type (usually added with the `typedef` tag).

The latest strategies which are included in Ivy by default are:

- latest-time
  compares the revision dates to know which is the latest. While this is often a good strategy in terms of pertinence, its drawback is that it can be slow when dealing with remote repositories. If you use ivyrep, for example, Ivy has to ask the HTTP server for the date of each Ivy file before knowing which is the latest.

- latest-revision
  compares the revisions as strings, using an algorithm close to the one used in PHP `version_compare` function. This algorithm takes into account the special meaning of some text. For instance, with this strategy, `1.0-dev1` is considered before `1.0-alpha1`, which in turn is before `1.0-rc1`, which is before `1.0`, which is before `1.0.1`.

- latest-lexico
  compares the revisions as strings using lexicographic order (the one used by Java string comparison).

## Child elements

Element | Description | Cardinality
--- | --- | ---
any latest strategy | adds a latest strategy to the list of available strategies | 0..n

## latest-revision

[since 1.4]

The latest-revision can now be configured to handle more words with special meanings than the one defined in PHP `version_compare` function.

Here is an example of how you can do so:

    <latest-strategies>
      <latest-revision name="mylatest-revision">
        <specialMeaning name="PRE" value="-2"/>
        <specialMeaning name="QA" value="4"/>
        <specialMeaning name="PROD" value="5"/>
      </latest-revision>
    </latest-strategies>

Knowing that the default "special meaning" words are the following:

        <specialMeaning name="dev" value="-1"/>
        <specialMeaning name="rc" value="1"/>
        <specialMeaning name="final" value="2"/>

You can even remove or redefine the default special meanings by setting `usedefaultspecialmeanings="false"` on the `latest-revision` tag. Example:

    <latest-strategies>
      <latest-revision name="mylatest-revision" usedefaultspecialmeanings="false">
        <specialMeaning name="pre" value="-2"/>
        <specialMeaning name="m" value="1"/>
        <specialMeaning name="rc" value="2"/>
        <specialMeaning name="prod" value="3"/>
      </latest-revision>
    </latest-strategies>