System

System is the root system module of the platform. It is pulled in automatically — every other module depends on it without an explicit REQUIRE. The module declares the root classes, the standard groups of properties and actions, the change-session control surface, the incoming HTTP-request context, the form-lifecycle actions, the application-identity properties, and the local buffers that the export, import, and value-request operators write to.

Root classes

Class	Purpose
Object	the base class of all user objects; parent of all user-defined classes
StaticObject	the base class for static objects (values declared in the module's source)
CustomObjectClass	meta-class object: every user class is represented here by one static object that carries statistics and skeleton properties

Standard groups

root / public / private are the roots of the group hierarchy. base (inside public), id (inside base), uid (inside id) are the standard subgroups for key properties. drillDown and propertyPolicy are separate roots for drill-down properties and access-policy properties. objects is a group typically used for properties that collect JSON structures in interactive forms.

Object metadata

class[Object] — the class of an object (as a CustomObjectClass). className[Object] — the class name as STRING. prevClassName[Object] — same, for the class value at the start of the session. For static objects: name[StaticObject] (name), caption[StaticObject] (display caption), order[StaticObject] (sort order), image[StaticObject] (picture). For a class as a whole: stat[CustomObjectClass] — estimated object count.

Change-session control

Property / action	What it does
apply[] / cancel[]	wrappers over the APPLY and CANCEL operators
canceled[]	flag set when the last APPLY was cancelled by a constraint
applyMessage[]	error message of the last APPLY (filled in by the platform itself)
ApplyFilter	a class with filter shortcuts: onlyCalc, onlyCheck, onlyData, session, withoutRecalc
applyFilter[] / applyOnlyCalc[] / applyOnlyCheck[] / applyOnlyData[] / applySession[] / applyOnlyWithoutRecalc[] / applyAll[]	set / clear the filter for the next APPLY
check[]	run APPLY under the onlyCheck filter with guaranteed filter restoration
sessionOwners[] / manageSession[]	the count of session owners and the flag for being a standalone session
throwException[TEXT]	raises an exception with the given message
setNoCancelInTransaction[] / dropNoCancelInTransaction[]	forbid / re-allow rollback inside a transaction
setNoEventsInTransaction[] / dropNoEventsInTransaction[]	forbid / re-allow events inside a transaction
executeLocalEvents[TEXT] / executeLocalEvents[]	force-run local events (optionally by filter)
beforeCanceled[] / requestCanceled[] / requestPushed[]	request-lifecycle flags
logMessage[]	message emitted into the system log on certain events
empty[] / empty[Object]	no-op actions

HTTP request context

The platform fills the following NESTED LOCAL properties on an incoming HTTP request and reads them on the outgoing response.

Incoming: headers[TEXT], cookies[TEXT], params[TEXT, INTEGER] (and the shortcut params[TEXT]), fileParams[TEXT, INTEGER] / fileParams[TEXT], actionPathInfo[], contentType[], body[], appHost[], appPort[], exportName[], method[], scheme[], webHost[], webPort[], contextPath[], servletPath[], pathInfo[], query[], insecureSSL[], timeoutHttp[].

Outgoing: headersTo[TEXT], cookiesTo[TEXT], statusHttp[], failedHttp[] (computed as statusHttp() < 200 OR statusHttp() >= 300), statusHttpTo[].

Derived URLs: origin[] (scheme://webHost:webPort), webPath[] (origin + contextPath), url[] (webPath + servletPath + pathInfo), apiOriginUrl[STRING] / apiOriginUrl[LINK] (API URL relative to origin), apiContextUrl[STRING] (API URL relative to webPath).

TCP: responseTcp[], timeoutTcp[].

Caught-exception state

Inside a CATCH block, messageCaughtException[], javaStackTraceCaughtException[], lsfStackTraceCaughtException[] give the message, the Java stack trace, and the lsFusion stack trace of the most recently caught exception.

Opening files and links

open[STRING] / open[FILE] / open[NAMEDFILE] / open[RAWFILE] / open[LINK] / open[RAWLINK] (with shorter overloads for the file name and the noWait flag) open the given value on the client in the associated application or browser.

htmlLinkInTab[HTMLLINK] opens an HTML link in a separate tab; the htmlLinkInTab form hosts the HTML viewer itself.

Form lifecycle

Property / action	What it does
formApply[]	apply (save) the form's changes (Alt+Enter)
formCancel[]	cancel the form's changes (Shift+Esc)
formRefresh[]	re-read the form's data (F5)
formOk[]	confirm and close a dialog (Ctrl+Enter)
formClose[]	close the form (Esc)
formDrop[]	drop the current form object (Alt+Delete)
formEditReport[]	edit the form's report template (Ctrl+E)
formShare[] / formCustomize[]	share the current state / open the form customization
formCustomizeBackground[] / formCustomizeShowIf[]	abstract properties (ABSTRACT COLOR() / ABSTRACT BOOLEAN()) used to customize the form-customization dialog
formApplied[]	abstract list of actions called after a successful form APPLY (the default shows a success notification)
navigatorRefresh[]	refresh the navigator
forceUpdate[STRING]	forcibly re-read a group of objects
seek[Object]	locate and activate an object on the current form
sleep[LONG]	pause for the given number of milliseconds

Form context flags

isActiveForm[], isDocked[], isEditing[], isAdd[], isManageSession[], isExternal[], showOk[], showDrop[], isDataChanged[] reflect the state of the current form and its interaction with the session. isEditable[] / isReadonly[] track whether the form is editable.

Polymorphic edit and delete

edit[Object] and delete[Object] are declared as abstract actions with default implementations (SHOW EDIT and DELETE) and are available for extension by specific user classes. formEdit[Object] is a direct pass-through to edit[Object]. formEditObject[Object] wraps formEdit[Object] in NEWSESSION only when the object already exists in the database (PREV(o IS Object)), and calls formEdit[Object] directly otherwise. formDelete[Object] calls delete[Object] directly when sessionOwners[] is set; otherwise it shows a confirmation prompt and on confirmation runs delete[Object] followed by APPLY.

Local buffers

The platform provides three parallel sets of local properties for different exchange stages:

• export… — where EXPORT writes its intermediate result. One property per built-in class: exportObject[], exportInteger[], exportLong[], exportDouble[], exportNumeric[], exportString[], exportText[], exportRichText[], exportHTMLText[], exportDate[], exportTime[], exportDateTime[], exportZDateTime[], exportYear[], exportBoolean[], exportTBoolean[], exportInterval<Type>[] for every interval class, exportColor[], exportJSON[] / exportJSONText[], exportXML[], exportHTML[], and the matching export<Class>File[] / export<Class>Link[] for every file and link class.
• requested… — the same buffers declared as NESTED for batched value prompts (INPUT / REQUEST).
• Import: importFile[], imported[INTEGER] and importedString[STRING[10]] — the flag that the corresponding "row" arrived from a flat file. inputList[INTEGER] / displayInputList[INTEGER] — the buffer of list values and captions. readFile[], readDialogPath[], showResult[] — the results of file reading, path selection, and message display.

Application identity

logicsName[] (from dataLogicsName), logicsCaption[], topModule[], displayName[] (computed as dataDisplayName ?? logicsCaption ?? topModule) — the application's name, caption, and display name. hashModules[] — the hash of the module set the server sees as initialized.

Graphics: logicsLogo[] (logo image), logicsIcon[] (application icon), PWAIcon[] (PWA icon, expected 512×512). Each comes with a triple load<Name>[] / open<Name>[] / reset<Name>[].

UI defaults

Property	Purpose
defaultBackgroundColor[] / defaultOverrideBackgroundColor[]	base background color; the OVERRIDE variant returns yellow (RGB(255,255,0)) when empty
defaultForegroundColor[] / defaultOverrideForegroundColor[]	base text color; the OVERRIDE variant is red
selectedRowBackgroundColor[] / selectedCellBackgroundColor[] / focusedCellBackgroundColor[] / focusedCellBorderColor[] / tableGridColor[]	user-defined colors for rows, cells, and grid
customReportCharWidth[] / reportCharWidth[]	character width in reports (default 8)
customReportRowHeight[] / reportRowHeight[]	row height in reports (default 18)
reportNotToStretch[] / reportToStretch[]	report content stretching control

Runtime and checks

checkIsServer[] / isServer[] — checks and the flag that the current execution runs on the server. random[] — DOUBLE between 0 and 1, randomUUID[] — md5 of a pair of random values, randInt[INTEGER] — an integer in [1; max]. notEmpty[STRING] — converts an empty string to NULL. upper[STRING] / lower[STRING] — case.

requestCanceled[] — a native property, flag of the current request being cancelled. noSystemToolbarCaptions[] — abstract flag for hiding system-toolbar captions. isHTMLSupported[] — a native property indicating whether the client supports HTML.

File helpers

file[RAWFILE, STRING] — assemble a FILE from raw bytes and an extension. file[FILE, STRING] — clone a FILE with a different extension. namedFile[…] — same for NAMEDFILE (with a name). name[NAMEDFILE], extension[FILE], extension[NAMEDFILE] — file components. md5[FILE] — MD5 hash. resourceImage[STRING] — a resource path as a file image for the UI.

Client-side loading

loadLibrary[STRING] / loadFont[STRING] — load a JS library or font on the client. reload[] — reload the client.

Windows and navigator

The module fixes the main windows: logo, root, system (the top horizontal bar), toolbar (the left vertical strip), forms (the central area), log (the right notification strip). Each window has an abstract CSS class (logoWindowClass[], …) for customization.

The navigator gets a system folder Administration with subfolders Application (options / integration / migration) and System (performance, notifications, scheduler, logs).

Language

• Module header — the MODULE / REQUIRE syntax; the System module is pulled in automatically.
• APPLY operator — underlies the session-control actions.
• CANCEL operator — cancels session changes.
• EXPORT operator — writes into the export… local buffers.
• IMPORT operator — fills imported, importedString, and related local properties.

See also

• System modules — the general inventory of platform modules.
• Time — the separate Time module pulled in via REQUIRE Time.
• Utils — the helper-property collection.
• Change sessions — the session concept and its commit.
• Forms — what a form is and how its lifecycle relates to the system actions.