Implement front call modules for GWC

Custom front call modules for the GWC-HTML5 theme front-end are implemented by using JavaScript™.

GWC-HTML5 theme custom front call basics

When using the GWC-HTML5 theme, front-end calls are JavaScript functions executed locally on the workstation where the browser is running.

Note: Executing front calls in the context of a web browser is limited to the OS functions a web browser can do. For example, it will not be possible to delete a file on the computer where the browser executes.

To implement custom front calls for GWC-HTML5 theme, you must edit the csf.js JavaScript file located in $FGLASDIR/tpl/SetHtml5. Genero built-in front calls and custom front calls are implemented in the csf.js file.

Important: Custom front call module and function names must be registered in lowercase for the GWC-HTML5 theme front-end.

Follow these steps to implement a custom front call module for the GWC-HTML5 theme:

Edit the $FGLASDIR/tpl/SetHtml5/csf.js file.
Add a JavaScript object using the name of the front call module to the gwc.frontCallModuleList object:
```
gwc.frontCallModuleList.mymodule = { ... }
```
Add your front call functions as JavaScript methods to the newly-created module object (with potential parameters):
```
gwc.frontCallModuleList.mymodule = { 
     myfunction : function ( param1, ... ) {
         ...
     }
}
```
The parameters of the JavaScript method must match the parameter list of the ui.Interface.frontCall("mymodule", "myfunction", [param-list], [return-list]).
If the front call must return values to the Genero program, add a return instruction in the JavaScript method:
```
    return ( [value1, ... ]);
```
The number of returned values must match the number of variables used in the return list of the Genero front call ui.Interface.frontCall("mymodule", "myfunction", [param-list], [return-list]).
If the front call does not return any value to the Genero program, the JavaScript method must return an empty list:
```
    return [];
```

Note:

If the SetHtml5 directory contains compressed .js files, do not forget to compress the modified csf.js file, or remove the compressed version of the file (the GAS will use the non-compressed version).
Keep in mind that the JavaScript modules can be cached in your browser. You may need to refresh the cache when doing modifications in the csf.js file.
Make sure to save your custom front call definitions added to csf.js before installing a new version of the GAS; the existing csf.js will be overwritten by the new installation.
Front call module and function names are case sensitive.

Example

Add the following lines in the csf.js file:

gwc.frontCallModuleList.mymodule = {
  myfunction1: function(param) {
    alert("param: " + param);
    return [];
  }
  myfunction2: function(param1,param2) {
    alert("param1: " + param1 + "\nparam2: " + param2);
    return [55,"aaa"];
  }
};

The above JavaScript code implements a front call module list with functions that can be called from the Genero programs as follows:

DEFINE r INTEGER, s STRING
CALL ui.Interface.frontCall("mymodule", "myfunction1", ["abc"], [] )
CALL ui.Interface.frontCall("mymodule", "myfunction2", [123,"abc"], [r,s] )

Implement front call modules for GWC - HTML5 theme

GWC-HTML5 theme custom front call basics

Example