Undeclared variables in Maya 2011, using MEL
Coming from a Java/C# background, the MEL site came as a bit of a letdown to me, maybe because I wasn't used to it, but didn't think it was as clear as some API sites.
I'm trying to write a MEL command to automate my save-as, rename file, save cycle. I know there must be some script out there already that does this, but I wanted to learn myself too
Initially, I want the user to click user-defined button from the shelf, and have a prompt-dialog, preloaded with the current scene name, with save-as and cancel button. Renaming and saving is fine, it's the separating out into functions (is there a difference between functions and procedures?) that started to spawn er开发者_运维知识库rors.
string $sceneName_new;
// Initiates the scene saving, checking filename meets standards
proc saveSceneAs() {
string $sceneName_old = `file -q -sceneName`;
string $result = `promptDialog
-title "Save scene as"
-message "Scene name:"
-button "Save" -button "Cancel"
-text $sceneName_old
-defaultButton "Save" -cancelButton "Cancel"
-dismissString "Cancel"`;
if ($result == "Save") {
$sceneName_new = `promptDialog -query -text`; // get result
$sceneName_new = strip($sceneName_new); // clean whitespace (start/end)
// check length of new name has at least one character
if (size($sceneName_new) < 1) {
print("Error: file name must contain at least one character. File not saved.\n");
} else if ($sceneName_old == $sceneName_new) {
confirmOverwriteOkay();
} else {
// good to save :D
saveScene($sceneName_new);
}
} else {
print("Cancelled. File not saved.\n");
}
}
// Asks user in case of unchanged filename, if okay to overwrite
proc confirmOverwriteOkay() {
string $overwriteConfirm = `promptDialog
-title "Warning"
-message "Are you sure you want to overwrite the current file?"
-text $sceneName_new;
-button "Yes, overwrite" -button "No, rename" -button "No, cancel"
-defaultButton "No, rename" -cancelButton "No, cancel"
-dismissString "No, cancel"`;
if ($overwriteConfirm == "Yes, overwrite") {
saveScene($sceneName_new);
} else if ($overwriteConfirm == "No, rename") {
// go back and try again
saveSceneAs();
} else {
print("Cancelled. File not saved.\n");
}
}
// Saves the scene with the given file name
proc saveScene(string $nameToSave) {
// TODO: rename, save file
print("File saved: " + $nameToSave);
}
saveSceneAs();
And the errors:
// Error: -text $sceneName_new; //
// Error: "$sceneName_new" is an undeclared variable. //
// Error: -button "Yes, overwrite" -button "No, rename" -button "No, cancel" //
// Error: Syntax error //
// Error: saveScene($sceneName_new); //
// Error: "$sceneName_new" is an undeclared variable. //
I solved this by adding the global keyword to the sceneName_new variable, and also declaring my use of it in the function it was called in - this will make the procedure use that global variable rather than create a new local one.
global string $sceneName_new;
// Asks user in case of unchanged filename, if okay to overwrite
proc confirmOverwriteOkay() {
global string $sceneName_new;
string $overwriteConfirm = `promptDialog
-title "Warning"
-message "Are you sure you want to overwrite the current file?"
-text $sceneName_new;
-button "Yes, overwrite" -button "No, rename" -button "No, cancel"
-defaultButton "No, rename" -cancelButton "No, cancel"
-dismissString "No, cancel"`;
if ($overwriteConfirm == "Yes, overwrite") {
saveScene($sceneName_new);
} else if ($overwriteConfirm == "No, rename") {
// go back and try again
saveSceneAs();
} else {
print("Cancelled. File not saved.\n");
}
}
You need use global keyword in $sceneName_new variable definition. Also you need to specify global variable in every procedure where you use it.
global string $sceneName_new;
proc saveSceneAs()
{
global string $sceneName_new;
//content
}
proc confirmOverwriteOkay()
{
global string $sceneName_new;
//content
}
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