Name: stack version

Synonyms: stack format, stack file format, stack file version

Type: glossary

Description:
When saving a binary <stack> using the <save> <command>, it is possible 
to save with a specific version of LiveCode's stack <file> format. This 
is useful when saving a binary stack so that it can be saved in an older
<version|version of LiveCode>, but it should be used with caution.

**Warning:** Using a non-default <stack version> could result in data
being lost when stacks are saved. In particular, any features that are
not present in the target version may be lost. For example, using a
<stack version> of "2.4" will cause any <blendLevel> or <ink> properties
to be lost.

These are the <stack version|stack file format versions> that can be
used with the <save> command, and the versions of LiveCode that they are
compatible with:

* "8.1": (Default) LiveCode 8.1.0 and later
* "8.0": LiveCode 8.0.0 up to LiveCode 8.1.0
* "7.0": LiveCode 7.0.0 up to LiveCode 8.0.0
* "5.5": LiveCode 5.5.0 up to LiveCode 7.0
* "2.7": LiveCode 2.6.1 up to LiveCode 5.5.0
* "2.4": LiveCode older than 2.6.1

When saving in the **8.0 format** paragraphs will be truncated where
length exceeds 32767 characters.

When saving in the **7.0 format**, all <widget|widgets> will be lost.

When saving in the **5.5 format**, all <Unicode> text will be lost
unless it is stored in a container that has a Unicode variant. For
example, this means that Unicode text in <field|fields> and <button>
labels will be saved, but any Unicode text in <script|scripts> or
<custom properties> will be lost.

When saving in the **2.7 format**, the following properties or property
aspects will also be lost:

* <textFont> property: separation lost
* <textStyle> property: separation lost
* <textSize> property: separation lost
* <unicodeToolTip> property: lost
* all paragraph level properties: lost
* separation of Unicode attribute of chars: lost
* character level metadata property: lost


When saving in the **2.4 format**, the following properties will also be
lost or altered:

* <antialiased> property: lost
* <ink> property: lost for <card|cards>, reverted to "GXcopy" for
  controls if not supported
* <opaque> property: lost for cards
* <blendLevel> property: lost


References: save (command), version (function), stack file (glossary),
stack (glossary), Unicode (glossary), field (glossary), button (glossary),
script (glossary), custom property (glossary), card (glossary),
widget (object), blendLevel (property), ink (property), 
textFont (property), textStyle (property), textSize (property),
unicodeToolTip (property), antialiased (property), opaque (property),
minStackFileVersion (property)
