macro.catchAbort: Difference between revisions
No edit summary |
mNo edit summary |
||
| Line 1: | Line 1: | ||
Introduced in version 1.5.0. The variable | Introduced in version 1.5.0. The variable {{code|macro.catchAbort}} can be used to override the behavior of the default {{func|abort}} function to continue execution instead of halting. | ||
Whenever you set {{code|macro.catchAbort}} to {{code|1}}, any use of {{func|abort}} in a subsequently called macro will not abort, but will trigger a return from the macro instead. | |||
The variable | The variable {{code|macro.catchAbort}} must be in the variable scope where the abort should be caught. It is not a general flag to turn off abort behavior, just temporarily in the macro or variable scope where it's set. | ||
==Usage== | ==Usage== | ||
Set this variable to 0 (default abort | Set this variable to {{code|0}} (default abort behavior) or {{code|1}} (catch aborts). | ||
<source lang="mtmacro" line> | <source lang="mtmacro" line> | ||
[h: macro.catchAbort = 0] | |||
[h: macro.catchAbort = 1] | [h: macro.catchAbort = 1] | ||
</source> | </source> | ||
==Examples== | ==Examples== | ||
When a macro is called by another macro, the called macro may use | When a macro is called by another macro, the called macro may use {{func|abort}} to cancel execution. Usually all macro execution would stop, so the calling macro would not continue. We can now override that default behavior by ''catching'' the abort. | ||
===Default behaviour=== | ===Default behaviour=== | ||
The macro below will not have any output because the default behavior is that any call to abort will stop the overall macro execution. Whatever code is defined after the call to abort is not executed. | The macro below will not have any output because the default behavior is that any call to {{func|abort}} will stop the overall macro execution. Whatever code is defined after the call to {{func|abort}} is not executed. | ||
{| class="wikitable" border="1" style="border-collapse:collapse;" | {| class="wikitable" border="1" style="border-collapse:collapse;" | ||
| Line 33: | Line 33: | ||
|} | |} | ||
=== | ===Catching the abort=== | ||
The macro below will output | The macro below will output {{code|defaultValue}} as the {{code|macro.catchAbort}} set to {{code|1}} prevents the call to {{func|abort}} from actually terminating execution. The example shows how to set a default value for any return value of a function/macro that has an {{func|abort}} call in it. The macro then re-enables the normal function of {{func|abort}} again by setting {{code|macro.catchAbort}} to {{code|0}}. As each macro has its own variable scope, this only affects calls to {{func|abort}} within the current macro or calls to other macros from the current macro. | ||
{| class="wikitable" border="1" style="border-collapse:collapse;" | {| class="wikitable" border="1" style="border-collapse:collapse;" | ||
| Line 50: | Line 50: | ||
|} | |} | ||
=== | ===Catching the abort with nested macro calls=== | ||
Same as in the above example, the calling macro below will output | Same as in the above example, the calling macro below will output {{code|defaultValue}} because we activate deferred aborts (in anything that this macro will call afterwards) with {{code|macro.catchAbort}} set to {{code|1}} . | ||
{| class="wikitable" border="1" style="border-collapse:collapse;" | {| class="wikitable" border="1" style="border-collapse:collapse;" | ||
Revision as of 13:45, 12 March 2019
Introduced in version 1.5.0. The variable macro.catchAbort can be used to override the behavior of the default abort() function to continue execution instead of halting.
Whenever you set macro.catchAbort to 1, any use of abort() in a subsequently called macro will not abort, but will trigger a return from the macro instead.
The variable macro.catchAbort must be in the variable scope where the abort should be caught. It is not a general flag to turn off abort behavior, just temporarily in the macro or variable scope where it's set.
Usage
Set this variable to 0 (default abort behavior) or 1 (catch aborts).
[h: macro.catchAbort = 0]
[h: macro.catchAbort = 1]Examples
When a macro is called by another macro, the called macro may use abort() to cancel execution. Usually all macro execution would stop, so the calling macro would not continue. We can now override that default behavior by catching the abort.
Default behaviour
The macro below will not have any output because the default behavior is that any call to abort() will stop the overall macro execution. Whatever code is defined after the call to abort() is not executed.
| Default abort Macro |
|---|
[h: resultText = "defaultValue"]
[h: resultText = abort(0)]
[r: resultText] |
Catching the abort
The macro below will output defaultValue as the macro.catchAbort set to 1 prevents the call to abort() from actually terminating execution. The example shows how to set a default value for any return value of a function/macro that has an abort() call in it. The macro then re-enables the normal function of abort() again by setting macro.catchAbort to 0. As each macro has its own variable scope, this only affects calls to abort() within the current macro or calls to other macros from the current macro.
| Catching abort |
|---|
[h: macro.catchAbort = 1]
[h: resultText = "defaultValue"]
[h: resultText = abort(0)]
[r: resultText]
[h: macro.catchAbort = 0] |
Catching the abort with nested macro calls
Same as in the above example, the calling macro below will output defaultValue because we activate deferred aborts (in anything that this macro will call afterwards) with macro.catchAbort set to 1 .
| Called macro using an abort as function doSomething() | Calling macro catching an abort |
|---|---|
[h: "this macro will do something and then abort"]
[h: "... doing something"]
[h: abort(0)] |
[h: macro.catchAbort= 1]
[h: resultText = "defaultValue"]
[h: resultText = doSomething()]
[r: resultText]
[h: macro.catchAbort= 0] |
See also
Version changes
- 1.5.0 - introduced macro.abortCatch