Mendix Intermediate Developer flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Persistable vs non-persistable

Persistable entities are stored in the database and automatically receive ID, CreatedDate and ChangedDate; non-persistable entities exist only in runtime memory and disappear when the request or session ends.

Association owner

An association belongs to the entity it is drawn from, and delete behaviour is configured there. Cascading delete removes the target object with the owner; otherwise only the link is removed.

System attributes

Every persistable entity inherits ID, CreatedDate, ChangedDate, ChangedBy and Owner from the System module. They are read-only in the domain model but usable in XPath and on pages.

Join entity

Mendix has no native many-to-many association. You model it with a join entity carrying two one-to-many associations, which can additionally hold attributes that describe the relationship.

Microflow transaction

A microflow executes within one database transaction. An unhandled error causes its uncommitted changes to be rolled back, while a boundary error event can intercept the error and continue.

Commit with events

This commit option runs before and after commit event handlers and validation rules. Commit without events writes straight to the database and skips both, which is faster but bypasses business rules.

Boundary error event

Placed on the border of an activity, call or loop, it catches exceptions raised there and lets the flow continue with rollback, continue, or a custom error page.

Retrieve by association

The Retrieve activity can follow an association path from a known object, for example $Order/Module.OrderLine, returning the associated objects without writing an XPath constraint.

Nanoflow

A nanoflow runs in the browser and supports offline apps. It can call microflows, perform client-side calculations and retrieve data when online, but has no server-side transaction of its own.

Data view context

A data view renders a single object supplied by a page parameter, a microflow or nanoflow data source, or an enclosing widget; without a context object its contents are hidden.

Conditional visibility expression

Visibility and editability properties accept boolean expressions such as $currentObject/Status = 'Open', evaluated in the browser using page parameters, attributes and client variables.

Data grid

A data grid displays a list as rows and columns with built-in sorting, paging and column configuration, whereas galleries and list views repeat a free-form template per object.

Module role

Module roles are defined inside each module and grant rights on entities, pages, microflows and nanoflows. User roles in app security combine one or more module roles for real users.

Entity access XPath constraint

An entity access rule can include an XPath constraint that limits which objects a module role may read; objects failing the constraint behave as if they do not exist for that role.

Production security

Production security enforces entity, page, microflow and nanoflow access rules and requires real authentication; prototype security allows demo users and leaves most access rules unenforced.

Microflow without access rules

Such a microflow is callable by every user and by client requests. Adding access rules restricts execution to the listed module roles and blocks unauthorised calls from pages or nanoflows.

Call REST service

A microflow activity that sends an HTTP request with configurable URL, method, headers, authentication and body, returning the response body, status code and headers as variables.

Import mapping

An import mapping converts a JSON or XML message into Mendix objects by matching element names to attributes and associations, and can be reused across REST and web service calls.

Published REST operation

An operation on a published REST resource, bound to an HTTP method and path, that invokes a microflow and uses import and export mappings to convert the request and response payload.

Consumed web service

Importing a WSDL creates a consumed web service document with generated XML schemas; a microflow activity then calls the external SOAP endpoint using those generated message definitions.

CustomJavaAction

The base class for Mendix Java actions. Your subclass implements executeAction, and the generated proxy class maps modeler parameters to typed Java arguments and converts the result back.

Core.microflowCall

A Core API method that lets Java code invoke a microflow by qualified name, pass parameters with withParam, and execute it in a given context, returning the microflow's result.

IMendixObject

The generic runtime handle for any entity instance in Java. Core methods such as create, retrieveId and commit operate on it, and generated proxy classes wrap it via getMendixObject().

userlib folder

The project folder holding third-party jars that are available to Java actions at runtime; adding or replacing a jar requires an application restart or redeploy to take effect.

Team Server

Mendix's Git-based repository hosting for projects. Studio Pro commits, updates and creates branch lines there, and deployment packages are built from the stored revisions.

Deployment package

A built artifact containing the compiled model, custom Java code and dependencies. It is created from a specific revision and deployed to an environment, but does not contain the source model.

Per-environment constants

Constant values can be overridden per environment in the cloud portal, so a single deployment package can target different endpoints, credentials or feature flags in acceptance and production.

Database synchronization

On startup Mendix compares the model with the database schema and adds missing tables and columns; incompatible changes fail and require a clean database or a manual migration.

N+1 query problem

Retrieving a list and then retrieving a related object inside a loop issues one query per row; a single XPath or association retrieve fetches all the data at once instead.

Retrieve range

The offset and amount settings on a Retrieve activity limit how many objects are returned, which enables paging and prevents large lists from being loaded into memory.

Log levels

Mendix supports trace, debug, info, warning, error and critical. Log message activities and Java logging appear in the cloud portal's log viewer for the selected environment.

Stateless microflow

A microflow marked stateless keeps no session state between calls, letting the runtime serve concurrent requests with fewer resources; it cannot use session variables or session-dependent data.