helloWorld.mel

// ***************************************************************************
//                              INSTALL MODULE
// ***************************************************************************
//
// DESCRIPTION:
//  Add the module which is located in the same directory as the .mel file 
//  into the first available MAYA_MODULE_PATH directory. It doesn't matter 
//  where on disk the module lives as the script will make sure the path in 
//  the .mod file links to the correct place. There are some basic sanity 
//  checks in place to make sure the script doesn't error out. This includes 
//  Maya version compatibility with the module. Permissions of the directories 
//  files have to be written to and incorrectly formatted module files.
//
// REQUIRES:
//  - Template .mod file ( replace regular file path with <PATH> )
//  - Maya module ( scripts/icons/plug-ins etc directories )
//
// USAGE:
//  source <MEL_FILE>;
//
// AUTHORS:
//  Robert Joosten - rwm.joosten@gmail.com
//
// LICENSE:
//  MIT
//
// VERSIONS:
//  1.0.0 - Aug 23, 2018 - Initial Release.
//  1.0.1 - Sep 17, 2018 - Allow for use in paths that contain a space.
//  1.0.2 - Oct 03, 2018 - Fix path error installing on UNIX.
//
// ***************************************************************************


proc string[] getModulePathsFromEnvironment()
{
    // get all of the paths in the MAYA_MODULE_PATH variable and split them 
    // into a string array.
    string $paths[];
    string $separator = (`about -nt`) ? ";" : ":";
    tokenize(getenv("MAYA_MODULE_PATH"), $separator, $paths);
    
    return $paths;
}

// ***************************************************************************


proc string findModuleFileInPath(string $path)
{
    // get the first module file found in the directory.
    string $files[] = `getFileList -folder $path -filespec "*.mod"`; 
    return $files[0];
}


proc string findModuleFileInModulePath(string $moduleFile, string $modulePaths[])
{ 
    // loop module paths
    for( $path in $modulePaths )
    {
        // find moduleFile in path
        string $files[] = `getFileList -folder $path -filespec $moduleFile`; 
        if ($files[0] != "")
            return $path;
    }
    
    // declare empty output
    string $empty;
    return $empty;
}


// ***************************************************************************


proc string[] readModuleFile(string $path)
{
    // read the module file and return each line as a string part of a string 
    // array.
    string $lines[];
    
    $fileId = `fopen $path "r"`;
    string $data = `fread $fileId $data`; 
    tokenize($data, "\n", $lines);
    
    return $lines;
}


// ***************************************************************************


proc string getConditionValue(string $line)
{
    // get the condition value by splitting the string on the : character and 
    // returning the second section of the partition.
    string $partitions[];
    tokenize($line, ":", $partitions);
    
    return $partitions[1];
}


// ***************************************************************************


proc string[] parseModuleLine(string $line)
{
    // declare output variable
    string $output[];  
    
    // declare default output
    string $mayaVersion;
    string $language;
    string $platform;

    // make sure its a module line by checking if the line starts with a + 
    // or -.
    if (startsWith($line, "+") == 0 && startsWith($line, "-") == 0)
        return $output;
    
    // get partitions
    string $partitions[];
    tokenize($line, " ", $partitions);
    
    // get partitions length
    $length = size($partitions);
    
    // loop partitions in reverse
    for( $i=1; $i<$length+1; ++$i )
    {
        // get reverse index
        int $index = $length - $i;
        string $part = $partitions[$index];

        // extract conditions
        if (startsWith($part, "MAYAVERSION") == 1)
        {
            $mayaVersion = getConditionValue($part);
            stringArrayRemoveAtIndex($index, $partitions);
        }
        else if (startsWith($part, "LANGUAGE") == 1)
        {
            $language = getConditionValue($part);
            stringArrayRemoveAtIndex($index, $partitions);
        }
        else if (startsWith($part, "PLATFORM") == 1)
        {
            $platform = getConditionValue($part);
            stringArrayRemoveAtIndex($index, $partitions);
        }
    }
    
    // set output
    $output[0] = $partitions[0];
    $output[1] = $partitions[1];
    $output[2] = $partitions[2];
    $output[3] = $partitions[3];
    $output[4] = $mayaVersion;
    $output[5] = $language;
    $output[6] = $platform;

    return $output;
}


// ***************************************************************************


proc string[] findModuleMatch(string $lines[])
{
    // get maya data
    string $mayaVersion = `about -version`;
    string $language = `about -uiLanguage`;
    string $platform = `about -operatingSystem`;
    
    // process module to see if its suitable for the current version of Maya.
    for($line in $lines)
    {
        // get line data
        string $lineData[] = parseModuleLine($line);
        
        // validate line data
        if ($lineData[0] == "")
            continue;
        
        // validate maya version
        if ($lineData[4] != "" && $lineData[4] != $mayaVersion) 
            continue;
            
        // validate language
        if ($lineData[5] != "" && $lineData[5] != $language) 
            continue;
            
        // validate platform
        if ($lineData[6] != "" && $lineData[6] != $platform) 
            continue;
            
        // return match
        return $lineData;
    }
    
    // declare empty output
    string $empty[];
    return $empty;
}


// ***************************************************************************


proc loadModuleExtended(string $moduleFile, string $path)
{
    // get separator
    string $separator = "/";

    // load module
    loadModule -load $moduleFile;
    
    // add scripts path to system path, for some reason after loading the 
    // module we are still not able to import the scripts even though the
    // path is available in the MAYA_SCRIPT_PATH.
    string $scriptPath = $path + $separator + "scripts";
    python("import sys; sys.path.append('" + $scriptPath + "')");
    
    // see if a userSetup.py is present in the script folder. If this is the 
    // case execute that file.
    string $userSetup = $scriptPath + $separator + "userSetup.py";
    if (`filetest -e $userSetup` == 1)
        python("import __main__; execfile('" + $userSetup + "', __main__.__dict__ )");
}


// ***************************************************************************


global proc installModule()
{
    // get path from mel file
    string $melWhatIs = `whatIs "installModule"`;
    string $melWhatIsPath = `match ": (.*)" $melWhatIs`;
    
    int $melSize = `size $melWhatIsPath`;
    string $melPath = `substring $melWhatIsPath 3 ($melSize-3)`;
    string $path = dirname($melPath);
    
    // get separator
    string $separator = "/";

    // find installed module
    string $modules[] = `moduleInfo -listModules`;
    
    // get module paths from the environment and choose the first one if this 
    // variable is not overwritten the .mod file will be written to this path.
    string $modulePaths[] = getModulePathsFromEnvironment();
    string $modulePathDefault;

    // find module in current directory
    string $moduleFileBase = findModuleFileInPath($path);
    
    // validate module
    if ($moduleFileBase == "") 
        error("\nNo template module file found in " + $path);
    
    // find full module path
    string $moduleFile = $path + $separator + $moduleFileBase;
        
    // read module content
    string $moduleContent[] = readModuleFile($moduleFile);
    
    // find module match
    string $moduleMatch[] = findModuleMatch($moduleContent);
    string $moduleName = $moduleMatch[1];
    string $moduleVersion = $moduleMatch[2];
    
    // validate module content
    if ($moduleName == "") 
        error("\nNo valid module information found matching the current version/language/platform of Maya in " + $moduleFile);
    
    // check if module already exists
    if (stringArrayContains($moduleName, $modules) == 1) 
    {
        string $moduleVersionExisting = `moduleInfo -moduleName $moduleName -version`;
        string $existingPath = `moduleInfo -moduleName $moduleName -path`;

        if ($moduleVersion == $moduleVersionExisting && $path ==$existingPath)
        {
            print("The " + $moduleName + " module, version " + $moduleVersion + " at " + $path + " is already installed!");
            return;
        }    
        
        // find existing module path
        $modulePathDefault = findModuleFileInModulePath($moduleFileBase, $modulePaths);
    }
    
    // get existing module path to the front of the list
    if ($modulePathDefault != "")
    {
        int $index = stringArrayFind($modulePathDefault, 0, $modulePaths);
        stringArrayRemoveAtIndex($index, $modulePaths);
        stringArrayInsertAtIndex(0, $modulePaths, $modulePathDefault);
    }
        
    // loop module paths
    for($modulePath in $modulePaths)
    {
        // only allow default path to be written if it exists
        if ($modulePathDefault != "" && $modulePathDefault != $modulePath)
            continue;
        
        // create dir in case it doesn't exist
        sysFile -makeDir $modulePath;
    
        // construct module path
        string $outputPath = $modulePath + $separator + $moduleFileBase;

        // write module file
        $fileId = `fopen $outputPath "w"`; 
        
        // if the default path exists error if the file cannot be written
        // this means the module has been installed by hand in a directory
        // that is not writable without administrator permissions. The error
        // will ask the user to copy the script by hand.
        if ($fileId == 0 && $modulePathDefault == $modulePath)
            error("\nThe " + $moduleName + " module, version " + $moduleVersion + " could not be updated as the current path it is installed in is not writable.\nPlease overwrite the " + $moduleFileBase + " file in " + $modulePath + ".");
        else if ($fileId == 0)
            continue;

        // write lines
        print("Content:\n");
        for($line in $moduleContent){
            string $processedLine = `substitute "<PATH>" $line $path`;
            print("    " + $processedLine + "\n");
            fprint $fileId ($processedLine + "\n");  
        }
        
        // print output
        print("Output:\n");
        print("    " + $outputPath + "\n");
            
        // close output path
        fclose $fileId;
        
        // load module
        loadModuleExtended($outputPath, $path);
        return;
    }
    
    // throw error as module has not been installed
    error("\nThe " + $moduleName + " module, version " + $moduleVersion + " could not be installed as non of the module paths were writable.");
}

// process
installModule();