Pre and post feature of the model package

Basics

You can pass a function name as "pre_process" or "post_process" to execute a function before or after the model package function call. 
            
    - 'pre_process' processing is available to the `set` and `create` functions
            
    - 'post_process' processing is available to the `get`, `get_from`, `set`, `create`, `list` functions and is executed at the end of the `_get` function.
                
Ex pre processing:

function set_region(fields)
    // Make sure a region is set. By default set as the location's region.
    if trim(fields.region) eq "" then
        // Get location
        location = my_location::get(fields.uid_location);
        if location.type() eq "sed_error::Error" then return location; endif
        fields.region = location.region;
    endif
    
    return fields;
endf

fields = {...};
entry = my_package::set(uid, fields, pre_process: "set_region");

            
Ex post processing:
    

function get_status(entry)
    // Define a status from existing conditions
    entry.status = "new";
    if trim(entry.sn_mdate) ne "" then
        entry.status = "modified";
    endif
    
    return entry;
endf

entry = my_package::get(uid, post_process: "get_status");

Ex post with list

function get_status(entry)
    // Define a status from existing conditions
    entry.status = "new";
    if trim(entry.sn_mdate) ne "" then
        entry.status = "modified";
    endif

    return entry;
endf

entries = my_package::list(uid: uid, options: {
    "post_process": "get_status"
});

Supercharging

The function used in 'pre_process' or 'post_process' can be in a package supercharge. When adding your 'pre_process' or 'post_process' parameter to your model package call, simply add the "package::" portion

Ex:

include "model/my_package.sn"

// Package supercharge
package my_package
    [...]
    function get_status(entry)
        [...]
        return entry;
    endf
endp

// In your resource or SPA page
entry = my_package::get(uid, post_process: "my_package::get_status");

Supercharging model package functions

It is ill advise to supercharge any of the native model package function. If you do so, improvments could be made to the model functions and your function supercharge could become incompatible (often silently) and could result in bugs hard to discover. It is however sometimes needed to perform tasks or follow business rules before or after certain model function calls. That is where the 'pre_process' and 'post_process' could help you.

Let say that after creating an entry in table 'my_package' your business rule indicate you to always need add an entry in another table. Here is an example:

include "model/my_package.sn"

// Package supercharge
package my_package
    [...]
    function post_create(entry)
        // Add event in my_event table
        fields = {
            ...,
            uid_reference: entry.uid
        };
        event = my_event::create(fields);
        if event.type() eq "sed_error::Error" then return event; endif

        // Do more stuff your business rule ask you to implement

        return entry;
    endf
endp

// In your resource or SPA page
fields = {...};
entry = my_package::create(fields, post_process: "my_package::post_create");

.