Q:   Are the following tasks possible with compiled Miva?

• Developing and running scripts without Empresa and without Compiler? Impossible
• Calling non-compiled Miva scripts from compiled ones? Impossible
• Generating and executing Miva code in run-time? Impossible
• Selfcreating or selfmodfying applications? Impossible
• Parsing user defined expressions in compiled applications? Impossible
• Custom modifications of modules without compiler? Impossible

WRONG! All of this is possible!

1. Features
2. Description
3. Installation
4. Calling Syntax
5. Examples of use
6. Supported tags / Compatibility
7. Limitations and known bugs
8. Support
9. Test / Demo
10. FAQ

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• Lightweight Miva Script parsing engine (interpreter).
• Platform independent. Runs on all platforms with a Miva Virtual Machine.
• Compatible to Miva Script v4 syntax.
• Drop-in solution. No installation necessary. No configuration.
• Miva Empresa not required. Miva Compiler not required.
• Can be used in compiled scripts to MvDO uncompiled Miva scripts.
• Can be used to replace macros in compiled scripts.
• Can be used for executing of code entered by the user or selfgenerated by the application.
• Can be used for executing code from a remote server.
• Can be used for executing code from a database. You can build function libraries in indexed databases.

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Vladdy is not designed for running big applications like Miva Merchant, but rather for executing non-compiled Miva applets from within compiled scripts or executing simpler non-compiled programs on machines without Empresa, with just the VM.

Its functionality is especially needed for many advanced developers who write self-modifying applications or use advanced techniques requiring parsing Miva expressions and/or tags in the run-time, for executing user-defined code and for implementing modification of modules without the necessity of recompiling them. It can be used to for replacing macros. It can be used also for storing libraries of functions in databases and executing them directly from them, or for executing of Miva Script code stored on remote servers.

It is a platform independent, completely drop-in solution, with absolutely no installation or configuration needed.

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Your server or PC must have the Miva Virtual Machine installed. Simply put the vladdy.mvc wherever you want in the Miva Script directory (public area). Call it through the browser in the following way:

or (on a local PC with Mia on port 8000):

Now you can test Miva Script expressions and Miva Script code through the web interface. It is highly recommended that you protect the file by password or IP through .htaccess , or by disabling the testing interface by clicking the " HIDE TEST " button. The test interface may be re-enabled by deleting the vladdy.hide file from the Miva data directory root.

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The syntax of the Miva Script expressions has to follow syntax rules of the MVM available on your machine. Syntax of Miva Script code follows the Miva Script v4 rules with the exceptions described in paragraphs   Supported tags / Compatibility  and  Limitations and known bugs

There are currently three function available for external calls from compiled Miva scripts:

• eval
• parse
• do
• doCall

where expression is a regular Miva Script expression stored either in a literal string, in any kind of variable (local, global, system, database) or as a result of a miva expression (may contain other functon calls). However, using a literal string makes usually few sense, because if you know the expression in advance, it is possible to compile and execute it directly without using the Vladdy parser. Vladdy engine is designed especially for executing and parsing Miva code that is not known at the compile time, cannot be included in the compiled file and therefore must be interpreted in the run-time.

Similarly as above, the code may be a string, variable or an expression. In contrary to eval , parse may contain complete Miva Script application, including any of the supported tags, ASCII text and HTML code.

Again, both arguments fileName and function may be strings, variables or an expressions. fileName contains a file name of a non-compiled Miva Script and function contains the name and arguments of a function to be called in the external file. If you want to execute the entire file instead of just a specific function, let the second argument empty ( '' ).

Unlike the built-in MvDO command, the do function is capable to execute files regardless if they are in the script or the data directory. Vladdy first checks for the presence of the file in the script directory and if it is not found it checks the data directory too.

doCall() loads a file from a location on a remote server, defined by the argument url , and (unlike MvCALL ) executes Miva Script contained on the page. If no Miva Script is included on the called document, it returns the text/html content. Please note that if the document is parsed by a Miva Script engine on the remote server, it usually does not contain any Miva tags (unless the remote script was explicitely designed so). Therefore, usually you have to use other than the default .mv extesnion at Miva Scripts designed for a remote execution.

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You can call the parser functions from your own compiled Miva Script application in the followig way:

For frequent use, it is recommended to declare the functions in the follwong way to avoid using the MvDO command:

<MvFUNCTION NAME="parse" PARAMETERS="code" STANDARDOUTPUTLEVEL="">
 <MvDO FILE="path/vladdy.mvc" NAME="l.ret" VALUE="{parse(code)}">
 <MvFUNCTRETURN VALUE="l.ret"> 
</MvFUNCTION>

Afterwards you can call the decalred function simply as any other function in MvEVAL, MvASSIGN, MvIF or any other Miva expression. For example:

<MvEVAL VALUE="{parse(fnLib.d.userPage)}">

<MvEVAL VALUE="{parse(g.myMacro)}">

<MvASSIGN NAME="l.ok" VALUE="{do('/test/test.mv','test()')}">

<MvIF EXPR="{g.admin AND eval(g.customCode)}">...

<MvSMTP TO="{eval(glosub(fnLib.d.verifyAdr,'%to%',g.to))}"...>

<MvEVAL EXPR="{doCall('http://server.com/path/mivaScript.txt'}">

...

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The pre-release version still does not support all Miva Script tags, but implemetning of them is in progress. Syntax of the code has to be conform to Miva Script v4 and is currently limited also by various bugs in the Miva Compiler v0.9.

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In addition to the above mentioned currently unsupported tags , and to the limitations given by the compiler v0.9 there are the following limitations:

• The use of local variables is very limited . Because of internal processing, local variables are being reset at each new command. Currently only global, system and database variables may be used.
• <MvFUNCTION> tag (user-defined functions) is currently not yet supported and the implementation may take longer time. It is currently not guaranteed that it will be included in the very near future.
• The engine is designed to run shorter scripts , functions, code modifications, etc. Running heavy applications could be slow.
• ASCII character 255 (on many systems displayed as y-umlaut / ÿ ) is reserved and should not be used anywhere in the code.
• The parse( ) , do( ) and doCall( ) functions currently support only script files without user-defined functions.
• Miva expressions (curly brackets) are currently not yet available in HTML tags.

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truXoft offers a   limited free suport   within 30 days after the date of the purchase for modules bought directly at   truXoft Co. or at affiliated resellers as listed below . The support is limited to fixing evident unknown bugs in the engine. It does not include any help with general Miva Script or Miva Virtual Machine problems. Before submitting any support query, please be absolutely to sure to have entirely read the chapters Limitations and known bugs and FAQ .

Some questions may be already answered in the FAQ or may be solved with the help of other more experienced users on the Miva Script User List . I am monitoring all Miva user lists and, if possible, will help with related problems posted to the user groups.

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A demo comes here as soon as MVM v0.9 or higher for Linux is available.