Function saved in a package won't load in the deployed CDF on startup

Question

I wrote a function and saved it in a package. I saved a copy of the package in the Autoload folder too. I deployed a CDF that contains this function. When I open the CDF later, this function (which represents modified input fields) is not evaluated. But when I do any operation that evaluates this function (like a button click), it gets evaluated and the cdf works just fine.

I am using Mathematica 9 to deploy the cdf and also to run it to check it.

Updated, the package's code down below -

BeginPackage["ModifiedInputFields`"] InputFieldsCreation[noOfrows_, 
 noOfInputFields_] :=
(

Module[
    {inputvaluelist = Table[0, {noOfrows}, {noOfInputFields}]},
    (
            If[
        (noOfrows > 0),
        (*If noOfrows value is greater than 0*)

        (
            {
                Table[
                         (
                            With[{i = i, j = j}, (Row[{

                                    Dynamic[InputField[
                                                Dynamic[inputvaluelist[[i, j]]],
                                                Number,
                                                ContinuousAction -> True,
                                                ImageSize -> {50, 20},
                                                Alignment -> Center

                                              ]]
                                    }])]
                            (*with is closed*)
                           ),
                            {i, 1, noOfrows},
                            {j, 1, Length[Part[inputvaluelist, i]]}
                    ],(*Table closed*)
                Dynamic[inputvaluelist]
            }

        ),
        ("")
      ]
        )
  ]
(*Module closed*)
)
EndPackage[] 

What I am looking at is to also be able to extract all the inputs that the user gives in the input fields into a list that we pass on to other functions. So that is a critical feature, which I am worried might also be a reason for the package giving trouble at cdf startup.

Answer 1

If you use Enterprise Mathematica edition, or some kind of signed version, you can do what you want. In this example I use the CDF with package to hide a database connection, so the package can be distributed without someone discover your connection user name and password.

There is the package, that should be saved together with the CDF file (same directory):

BeginPackage["connectionPack`",{"DatabaseLink`"}]

marcheConn::usage="myConn[] connect to database";

Begin["`Private`"]

myConn[] := 
   OpenSQLConnection[
        JDBC["Microsoft SQL Server(jTDS)", "myIPAddress"], 
        "Username" -> "userName", 
        "Password" -> "password"
    ];

End[]
EndPackage[]

Here is the code for the test CDF

testCDF=DynamicModule[{},

    Column[{
            Button["Random Sample from Database",output=test[]],
            Button["Current directory",output=Directory[]],
            Dynamic[output//TableForm]
          }]

   ,Initialization:>(
      SetDirectory[NotebookDirectory[]];
      Needs["connectionPack`",NotebookDirectory[]<>"connectionPack.m"];
      test[]:=Module[{conn,r},
            conn=connectionPack`myConn[]; 
            r=SQLExecute[conn,"select * from someTable"];
            CloseSQLConnection[conn];
            RandomSample[r,5]
            ];
    )
]

Now you can export this using:

CDFDeploy["test.cdf", testCDF, "Method" -> "Standalone", "Target" -> "PlayerPro"]

Important points:

• When using Needs inside Initialization use the full package directory in the second argument.
• When using the functions from your package inside Initialization you should use it full name as connectionPack`myConn[]
• Just for completeness of this example. If you wand to protect you connection string you could Encode and use SetAttributes[myConn, {ReadProtected,Locked}];. This way user can not retrive it using ??myConn.

update

I discovered that the encryption do not solve the conn security. When you create the connection, you can retrieve all connections parameters just executing conn. The only advantage is that the user needs Mathematica to do this, and user and pass will not be in plain text.

Answer 2

From the docs: "Because CDF Player cannot load custom data at runtime, you must ensure that all necessary information is embedded within the interactive elements of your .cdf file. This can be done with either Initialization or SaveDefinitions; both are options to Manipulate."