$ListSav and $ListSave: Difference between revisions
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==Syntax== | ==Syntax== | ||
<p class="syntax"><section begin="syntax" />[% | <p class="syntax"><section begin="syntax" />[%result =] $ListSav(list_identifier, name) | ||
[%result =] $ListSave(list_identifier, name) | |||
<section end="syntax" /></p> | <section end="syntax" /></p> | ||
<p class="caption">%result is set either to 0 or, if an error has occurred, to a negative number.</p> | <p class="caption">%result is set either to 0 or, if an error has occurred, to a negative number.</p> | ||
A $list "saved" via <var>$ListSav</var> or <var>$ListSave</var> will be cleaned up at user logoff. After a $list has been "saved" via <var>$ListSav</var> or <var>$ListSave</var> it is no longer accessible in the current request, but will not be cleaned up at request termination or RELEASE ALL RECORDS processing. The $list is effectively "hidden" until restored via <var>$ListRst</var> or <var>$List_Global</var>. | ==Usage notes== | ||
<ul> | |||
<li>A $list "saved" via <var>$ListSav</var> or <var>$ListSave</var> will be cleaned up at user logoff. After a $list has been "saved" via <var>$ListSav</var> or <var>$ListSave</var> it is no longer accessible in the current request, but will not be cleaned up at request termination or RELEASE ALL RECORDS processing. The $list is effectively "hidden" until restored via <var>$ListRst</var> or <var>$List_Global</var>. | |||
Only one $list can be saved at a time under a given name. For example: | <li>Only one $list can be saved at a time under a given name. For example: | ||
<p class="code">B | |||
FOR %I FROM 1 TO 4 | |||
%LIST1 = $ListNew | |||
%RESULT = $ListAdd(%LIST1 , - | |||
$WORD('HE SHE WE IT', , %I) WITH ' ATE') | |||
%RESULT = $ListSave(%LIST1, $WORD('A', , %I)) | |||
END FOR | |||
END | |||
</p> | |||
The request above produces three $lists, as follows: | The request above produces three $lists, as follows: | ||
<ol> | <ol> | ||
<li>< | <li><code>HE ATE</code>, successfully saved via <var>$ListSave</var> under name <code>A</code> | ||
<li>< | <li><code>SHE ATE</code>, successfully saved via <var>$ListSave</var> under name '' | ||
<li>< | <li><code>IT ATE</code>, not saved, but accessible under $list identifier %result for the duration of the request | ||
</ol> | </ol> | ||
The string < | The string <code>WE ATE</code> is not saved (a list was already saved with the name ''), and since each invocation of <var>[[$ListNew]]</var> deletes the list associated with it, the list containing <code>WE ATE</code> was deleted in the last iteration of the <var>FOR</var> loop. | ||
If <var>$ListSav</var> or <var>$ListSave</var> is invoked only with a null name argument, CCATEMP is not used and processing is very efficient. Because many Sirius Software products use $LISTSAV/$LISTRST with the null global $list name, care should be taken of the interaction between global $list names used by your applications and the null $list name. | <li>If <var>$ListSav</var> or <var>$ListSave</var> is invoked only with a null name argument, CCATEMP is not used and processing is very efficient. Because many Sirius Software products use $LISTSAV/$LISTRST with the null global $list name, care should be taken of the interaction between global $list names used by your applications and the null $list name. | ||
To ensure that a <var>$ListSav</var> or <var>$ListSave</var> is not blocked by a previously "saved" list under a given name, you can simply issue a <var>$ListRst</var> to restore any previously saved list under that name, as in | <li>To ensure that a <var>$ListSav</var> or <var>$ListSave</var> is not blocked by a previously "saved" list under a given name, you can simply issue a <var>$ListRst</var> to restore any previously saved list under that name, as in | ||
<p class="code"> % | <p class="code">%result = $ListDel($ListRst) | ||
%result = $ListSave(%list) | |||
</p> | </p> | ||
Another way to address the problem of a global $list name already in use is to use the <var>$List_Global</var> function. | Another way to address the problem of a global $list name already in use is to use the <var>$List_Global</var> function. | ||
<var>$Lists</var> saved with <var>$ListSave</var> can also be accessed with <var>$List_Global</var>. For example, | <li><var>$Lists</var> saved with <var>$ListSave</var> can also be accessed with <var>$List_Global</var>. For example, | ||
<p class="code"> % | <p class="code">%result = $ListSave(%alist, 'MY.GLOBAL.LIST') | ||
% | %list = $List_Global('MY.GLOBAL.LIST') | ||
</p> | </p> | ||
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the contents of global list MY.GLOBAL.LIST would be saved under the name OTHER.GLOBAL.LIST. MY.GLOBAL.LIST would still be a valid global $list but would be empty. | the contents of global list MY.GLOBAL.LIST would be saved under the name OTHER.GLOBAL.LIST. MY.GLOBAL.LIST would still be a valid global $list but would be empty. | ||
The only difference between <var>$ListSav</var> and <var>$ListSave</var> is that <var>$ListSav</var> will not allow the saving of an empty $list while <var>$ListSave</var> will and that <var>$ListSave</var> will replace an existing saved $list by the same name as long as the existing list is not active as a <var>$List_Global</var> list in the current procedure. For example, in | <li>The only difference between <var>$ListSav</var> and <var>$ListSave</var> is that <var>$ListSav</var> will not allow the saving of an empty $list while <var>$ListSave</var> will and that <var>$ListSave</var> will replace an existing saved $list by the same name as long as the existing list is not active as a <var>$List_Global</var> list in the current procedure. For example, in | ||
<p class="code"> %RESULT = $ListSav(%ALIST, 'A.LITTLE.LIST') | <p class="code">%RESULT = $ListSav(%ALIST, 'A.LITTLE.LIST') | ||
%RESULT = $ListSav(%BLIST, 'A.LITTLE.LIST') | |||
</p> | </p> | ||
the second <var>$ListSav</var> would fail because a $list is already saved under the name <tt>A.LITTLE.LIST</tt>. While in | the second <var>$ListSav</var> would fail because a $list is already saved under the name <tt>A.LITTLE.LIST</tt>. While in | ||
<p class="code"> %RESULT = $ListSave(%ALIST, 'A.LITTLE.LIST') | <p class="code">%RESULT = $ListSave(%ALIST, 'A.LITTLE.LIST') | ||
%RESULT = $ListSave(%BLIST, 'A.LITTLE.LIST') | |||
</p> | </p> | ||
the second <var>$ListSave</var> would succeed.<p> | the second <var>$ListSave</var> would succeed. | ||
</ul> | |||
===$ListSav and $ListSave completion codes=== | |||
<p class="code"> 0 — $list successfully saved | |||
-3 — No room to add list name | |||
(if LISTFC <var>$SirParm</var> parameter not set) | |||
-5 — Required argument not specified | |||
-6 — $List identifier invalid | |||
-13 — Another $list has already been saved with the | |||
specified name | |||
-14 — $list is null, is not saved ($ListSav only) | |||
</p> | </p> | ||
<h2>Products authorizing $ListSav and $ListSave</h2> | <h2>Products authorizing $ListSav and $ListSave</h2> | ||
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</ul> | </ul> | ||
[[Category:$Functions|$ListSav and $ListSave]] | [[Category:$Functions|$ListSav and $ListSave]] |
Revision as of 21:54, 25 October 2012
$ListSav and $ListSave: Save global $list
Most Sirius $functions have been deprecated in favor of Object Oriented methods. There is no direct OO equivalent for the $ListSav and $ListSave functions because Stringlists can, more naturally, be declared as "Global".
These $functions are used to save a $list to be later retrieved with the $ListRst function or the $List_Global and $List_Session functions. $ListSav and $ListSave are used with $ListRst or $List_Global to pass a $list between separate requests.
The $ListSav and $ListSave functions accept one required argument and one optional argument and return a numeric result. Both are callable $functions (see Calling Sirius Mods $functions).
The first argument is the identifier of the $list to be saved. This is a required argument.
The second argument is a string which is the name under which to save the $list. If this argument is omitted, the name is the null string. The $ListRst function can be given the name under which the $list was saved.
Syntax
<section begin="syntax" />[%result =] $ListSav(list_identifier, name) [%result =] $ListSave(list_identifier, name) <section end="syntax" />
Usage notes
- A $list "saved" via $ListSav or $ListSave will be cleaned up at user logoff. After a $list has been "saved" via $ListSav or $ListSave it is no longer accessible in the current request, but will not be cleaned up at request termination or RELEASE ALL RECORDS processing. The $list is effectively "hidden" until restored via $ListRst or $List_Global.
- Only one $list can be saved at a time under a given name. For example:
B FOR %I FROM 1 TO 4 %LIST1 = $ListNew %RESULT = $ListAdd(%LIST1 , - $WORD('HE SHE WE IT', , %I) WITH ' ATE') %RESULT = $ListSave(%LIST1, $WORD('A', , %I)) END FOR END
The request above produces three $lists, as follows:
HE ATE
, successfully saved via $ListSave under nameA
SHE ATE
, successfully saved via $ListSave under nameIT ATE
, not saved, but accessible under $list identifier %result for the duration of the request
The string
WE ATE
is not saved (a list was already saved with the name ), and since each invocation of $ListNew deletes the list associated with it, the list containingWE ATE
was deleted in the last iteration of the FOR loop. - If $ListSav or $ListSave is invoked only with a null name argument, CCATEMP is not used and processing is very efficient. Because many Sirius Software products use $LISTSAV/$LISTRST with the null global $list name, care should be taken of the interaction between global $list names used by your applications and the null $list name.
- To ensure that a $ListSav or $ListSave is not blocked by a previously "saved" list under a given name, you can simply issue a $ListRst to restore any previously saved list under that name, as in
%result = $ListDel($ListRst) %result = $ListSave(%list)
Another way to address the problem of a global $list name already in use is to use the $List_Global function.
- $Lists saved with $ListSave can also be accessed with $List_Global. For example,
%result = $ListSave(%alist, 'MY.GLOBAL.LIST') %list = $List_Global('MY.GLOBAL.LIST')
is a valid program. While a name is accessed as a global, however, it is not possible to save another list to the same name. In
%LIST = $List_Global('MY.GLOBAL.LIST') %RESULT = $ListSave(%ALIST, 'MY.GLOBAL.LIST')
the $ListSave would fail with a return code of -13. It is possible to $ListSave a global $list to a separate name. In
%LIST = $List_Global('MY.GLOBAL.LIST') %RESULT = $ListSave(%LIST, 'OTHER.GLOBAL.LIST')
the contents of global list MY.GLOBAL.LIST would be saved under the name OTHER.GLOBAL.LIST. MY.GLOBAL.LIST would still be a valid global $list but would be empty.
- The only difference between $ListSav and $ListSave is that $ListSav will not allow the saving of an empty $list while $ListSave will and that $ListSave will replace an existing saved $list by the same name as long as the existing list is not active as a $List_Global list in the current procedure. For example, in
%RESULT = $ListSav(%ALIST, 'A.LITTLE.LIST') %RESULT = $ListSav(%BLIST, 'A.LITTLE.LIST')
the second $ListSav would fail because a $list is already saved under the name A.LITTLE.LIST. While in
%RESULT = $ListSave(%ALIST, 'A.LITTLE.LIST') %RESULT = $ListSave(%BLIST, 'A.LITTLE.LIST')
the second $ListSave would succeed.
$ListSav and $ListSave completion codes
0 — $list successfully saved -3 — No room to add list name (if LISTFC $SirParm parameter not set) -5 — Required argument not specified -6 — $List identifier invalid -13 — Another $list has already been saved with the specified name -14 — $list is null, is not saved ($ListSav only)