The usage of Overarch is twofold. On the one hand, it is an open data format to describe the concepts, functional requirements, architecture, and design of software systems. On the other hand it is a tool to transform the description into diagrams, reports or other representations.
Overarch can be used as a CLI tool to convert specified models and diagrams into different formats, e.g. the rendering of diagrams in PlantUML or the conversion of the data to JSON.
Overarch supports modelling the functional requirements, the architecture and the design of the system under description.
Modelling a system with overarch should provide a value for the project and this guides the selection of model elements and supported abstractions and views.
The model contains all the elements relevant in the architecture of the system. Models are specified in the Extensible Data Notation (EDN).
The Extensible Data Notation EDN is a data notation with a rich set of literals for scalar and composite data types. It is also a subset of the Clojure language textual format. Therefore Clojure plugins/extensions for editors or IDEs provide syntax checking/highlighting and code completion.
Compared to JSON, which only supports literals for numbers, strings, vectors (arrays) and maps, EDN provides a richer set of data literals, e.g. integer and floating point numbers, big integers and decimals, strings, symbols, keywords, UUIDs and instants of time. It also provides literals for list, vectors, sets and maps.
The following literals are used in Overarch models and views.
Strings are used e.g. as names and descriptions of model elements and for the title of views.
"This is a string"
"This is
a multiline
string"Keywords are used as keys in the maps for model elements and views. They are also used as identifiers for model elements and views.
Keywords start with a colon (':'), have an optional namespace followed by a slash ('/') and a mandatory name, e.g. :namespace/name.
Keywords should be prefixed with a namespace to avoid collisions with keywords for other models, which is especially relevant for identifiers or for custom keys in the model elements and views.
:keyword
:namespaced/keywordUnprefixed keywords and the namespace 'overarch' for map keys are reserved for overarch. Please use your own prefix if you want to add custom information to the maps in the model.
Sets are unordered collections of elements without duplicates. They are used as top level collections for the model elements and views. They are also used as a container for the children of model elements.
#{"a" "b" "c"}Maps are associative collections of key/value pairs. They are used to describe the attributes of model elements and views.
{:firstname "John" :lastname "Doe" :age 42}Vectors are ordered collections of elements which may contain an element multiple times. They are used for the elements as content of a view because the ordering of the elements may be relevant for the rendering of the view (e.g. in PlantUML).
[1 2 3 4]
["John" "Doe"]As you can see in the example models, all collection literals can be nested.
For more information see the EDN specification.
The model and diagram descriptions of the C4 model banking example can be found in models/banking folder:
If you have a Clojure environment in some editor or IDE, just use it. If not, try Visual Studio Code with the Calva and PlantUML extensions. With this setup you get an editor for the EDN files with code completion, syntax check and syntax highlighting.
You can split your model into separate EDN files, which might be reasonable for big systems. Overarch can recursively read all models from a directory or search path so you are quite free in structuring your model files.
The top level element in each model EDN file is a set which contains the top level model elements. Model elements are denoted as maps in the EDN file.
All model elements have at least two keys, :el for the type of the element and :id for the identifier. The identifiers should be namespaced keywords, so that different models can be composed without collisions of the identifiers.
Model Nodes describe the elements of the different kind of models for the system.
| key | type | values | description |
|---|---|---|---|
| :el | keyword | see model elements | type of the model node |
| :id | keyword | namespaced id | id of the model node |
| :name | string | short name | name of the model node |
| :desc | string | description of the model node | |
| :tags | set of strings | e.g. #{"critical"} | some tags which can be used in element selection |
| :ct | set of maps | model nodes | the children of the model node |
Relations describe the connections and interactions of the nodes.
| key | type | values | description |
|---|---|---|---|
| :el | keyword | e.g. :rel, :request | type of the relation |
| :id | keyword | namespaced id | id of the relation |
| :from | keyword | namespaced id | id of the referrer node |
| :to | keyword | namespaced id | id of the referred node |
| :name | string | name of the relation | |
| :desc | string | description of the relation | |
| :tags | set of strings | e.g. | some tags which can be used in element selection |
References refer to a model element with the given id. They are primarily used to refer to the model elements to include in views. They can also be used to refer to model elements in other model elements, e.g. to split a huge hierarchical systems into multiple EDN files.
References can have other keys, which are merged with the referred element in
context of the reference. For example you can mark an internal system as external
in the context of a specific view by adding :external true to the reference.
Boundaries group related elements and are normally rendered as a dashed box in a view. There are currently 4 types of boundaries, two of them implicit.
The implicit boundaries are the system boundary and the container boundary. They are not modelled explicitly but are rendered for referenced systems and containers in specific views. A system boundary is rendered, when an internal system with containers as content is referenced in a container view or component view. Likewise a container boundary is rendered for a referenced container in a component view.
The explicit boundaries are enterprise boundary and context boundary.
These are explicitly modelled.
An enterprise boundary {:el :enterprise-boundary} can be used to group
systems by enterprise or company.
A context boundary {:el :context-boundary} can be used to group concepts,
containers or components by some common context, especially by domain contexts
in the sense of domain driven design.
Overarch supports elements for C4 architecture models.
| key | type | values | description |
|---|---|---|---|
| :subtype | keyword | :database, :queue | specific role of the model node |
| :external | boolean | true, false | default is false |
| :tech | string | technology of the model node |
Persons are internal or external actors of the system.
{:el :person
:id :banking/personal-customer
:name "Personal Banking Customer"
:desc "A customer of the bank, with personal banking accounts."}
A System is the top level element of the C4 model an can contain a set of containers. Systems can be internal or external to the project context. The structure of internal systems is modelled with containers.
A container is a part of a system. It represents a process of the system (e.g. an executable or a service). Containers are composed of a set of components.
A component is unit of software, which lives in a container of the system.
Relations describe the connections and interactions of the parts of a view.
| kind | sync/async | dependency | description |
|---|---|---|---|
| :request | sync | true | synchrounous request |
| :response | sync | false | response to a synchronous request |
| :send | async | true | asynchronous point-to-point message |
| :publish | async | true | asynchronous broadcast message (via broker, topic, queue) |
| :subscribe | async | true | subscribtion to an asynchronous broadcast message (via broker, topic, queue) |
| :dataflow | unspecified | unspecified | flow of data independent of the call semantic |
| :rel | unspecified | unspecified | unclassified relation |
| key | type | values | description |
|---|---|---|---|
| :tech | string | e.g. "REST" | technology of the relation |
Example (exerpt from the banking model containing context and container level elements):
#{{:el :person
:id :banking/personal-customer
:name "Personal Banking Customer"
:desc "A customer of the bank, with personal banking accounts."}
{:el :system
:id :banking/internet-banking-system
:name "Internet Banking System"
:desc "Allows customers to view information about their bank accounts and make payments."
:ct #{{:el :container
:id :banking/web-app
:name "Web Application"
:desc "Deliveres the static content and the internet banking single page application."
:tech "Clojure and Luminus"}
{:el :container
:id :banking/single-page-app
:name "Single-Page Application"
:desc "Provides all of the internet banking functionality to customers via their web browser."
:tech "ClojureScript and Re-Frame"}
{:el :container
:id :banking/mobile-app
:name "Mobile App"
:desc "Provides a limited subset of the internet banking functionality to customers via their mobile device."
:tech "ClojureScript and Reagent"}
{:el :container
:id :banking/api-application
:name "API Application"
:desc "Provides internet banking functionality via a JSON/HTTPS API."
:tech "Clojure and Liberator"}
{:el :container
:subtype :database
:id :banking/database
:name "Database"
:desc "Stores the user registration information, hashed authentication credentials, access logs, etc."
:tech "Datomic"}}}
{:el :system
:id :banking/mainframe-banking-system
:external true
:name "Mainframe Banking System"
:desc "Stores all the core banking information about customers, accounts, transactions, etc."}
{:el :system
:id :banking/email-system
:external true
:name "E-mail System"
:desc "The internal Microsoft Exchange email system."}
; Context level relations
{:el :rel
:id :banking/personal-customer-uses-internet-banking-system
:from :banking/personal-customer
:to :banking/internet-banking-system
:name "Views account balances and makes payments using"}
{:el :rel
:id :banking/internet-banking-system-uses-email-system
:from :banking/internet-banking-system
:to :banking/email-system
:name "Sends e-mail using"}
{:el :rel
:id :banking/internet-banking-system-using-mainframe-banking-system
:from :banking/internet-banking-system
:to :banking/mainframe-banking-system
:name "Gets account information from, and makes payments using"}
{:el :rel
:id :banking/email-system-sends-mail-to-personal-customer
:from :banking/email-system
:to :banking/personal-customer
:name "Sends e-mail to"}} Overarch also supports elements for C4 deployment models.
A node is a unit in a deployment view. Nodes represent parts of the infrastructure in which the containers of the system are deployed. They can contain a set of other nodes or containers.
| relation type | description |
|---|---|
| :link | A link between two nodes of the deployment model, e.g. two virtual networks |
| :deployed-to | A deployment relation between a container and a node in the deployment model |
| :rel |
A concept model captures relevant concepts of the domain(s) of the system. The concepts could be part of the ubiquous language of the systems domain.
A concept model can contain the concepts of the domain and the high level elements of the architecture model, e.g. the persons (actors), external systems and the system itself with it's containers.
A concept which is relevant for the domain of the system. The description should document the meaning of the concept.
Concepts can be related with other concepts.
| relation type | description |
|---|---|
| :is-a | the :from node is a specialization of the :to node |
| :has | the :from node is a part or attribute of the :to node |
| :rel | unclassified relation between the nodes |
A use case model captures the functionality a system is suposed to deliver. High level use cases provide an overview of this functionality and may link to business processes, domain stories and arcitectural elements.
As such they provide a pivot for the traceability from business processes into the design of the system.
The elements of the use case model are mainly borrowed from the UML use case model so prior knowledge of UML modelling applies here.
Example Use Case Model
A use case describes the goal of an actor in the context of the system described. The goal can be a concrete user goal, a high level summary of user goals or a subfunction of a user goal. This is captured by the :level key.
| key | type | values | description |
|---|---|---|---|
| :level | keyword | :summary :user-goal :subfunction | specific role of the element |
| :ext-points | string | extension points of a use case |
Persons, systems and containers from the architecture model should be used as actors in the use case model to provide a connection between the architecture model and the use case model.
You can use the :actor element to model actors not present as persons or systems in the architectural model, but this should be avoided if possible. A reason for an :actor element might be the introduction of a time actor to model the scheduling of use cases.
Relations connect actors to the use cases or use cases with other use cases. Use case models support different kinds of relations.
| kind | description |
|---|---|
| :uses | a use case element uses another use case element (e.g. an actor uses a use case or a use case uses an external system) |
| :include | a use case includes the functionality of another use cases |
| :extends | a use case extends the functionality of another use case |
| :generalizes |
A state model describes a state machine which can be used to model the states a system component can be in and the transition from one state to the next state based on the events the system receives as input.
The elements of the class model are mainly borrowed from the UML class model so prior knowledge of UML modelling applies here.
Example State Model
A state machine is the root element for a state machine view. It contains the set of states and transistions as value of the :ct key.
A simple state machine has at least one start state, some normal states to model the different states a system can be in, and at least one end state.
A start state starts the state machine and an end state terminates the state machine.
States can be compound, they can have an internal state machine. This is modelled as a set of states and transitions in the :ct key, analog to the state machine itself.
A transition connects two states and models the input that leads to the transition from the current state (:from) to the next state (:to).
You can split a transition to trigger multiple new states with a fork state. A fork has a single input transition and multiple output transitions.
To join multiple transitions after a fork a join state is used. A join has multiple input transitions and a single output transition.
A class model captures the static structure of the code.
The abstraction level of a class model is not very high compared to the actual implementation. Therfore modelling and updating a complete class model is not of much value. But class models of the domain can be very valuable as a means of communication between domain experts and developers to shape and document the domain model for a bounded context.
The elements of the class model are mainly borrowed from the UML class model so prior knowledge of UML modelling applies here.
Packages and namespaces provide a hierarchical structure for the organisation of the elements of the class model.
Packages and namespaces are treated the same, so use what suits your system best.
Interfaces and protocols specify related methods. Interfaces also provide a type for the static type system.
Interfaces and protocolls are treated the same, so use what suits your system best.
A class in object orientation is a typed element that encapsulates state and behaviour. The state is modelled with fields, the behaviour with methods.
In functional programming, you can use classes to model the values of your system.
An enumeration is a typed enumeration of values.
A field is part of the state of a class.
A method is part of the behaviour of a class or an interface.
A function is a first class element in functional programming. It has input parameters and calculates results.
Model elements can be selected based on criteria. Criterias are given as a map where each key/value pair specifies a criterium for the selection. An element is selected, if it matches all criteria in the map (logical conjunction).
Criterias can also be given as a vector of criteria maps. An element is selected, if it is selected by any of the critria maps (logial disjunction).
| key | type | example values | description |
|---|---|---|---|
| :key? | vector | [:tech true] | elements for which the check for the key returns the value (useful for custom keys) |
| :key | vector | [:tech "Clojure"] | elements for which the lookup of the key returns the value (useful for custom keys) |
| :el | keyword | :system | elements of the given type |
| :els | set of keywords | #{:system :person} | elements with one of the given types |
| :namespace | string | "org.soulspace" | elements with the given id namespace |
| :namespaces | set of strings | #{"org.soulspace"} | elements with one of the given id namespaces |
| :namespace-prefix | string | "org" | elements with the given id namespace prefix |
| :from-namespace | string | "org.soulspace" | relations with the given id namespace of the from reference |
| :from-namespaces | set of strings | #{"org.soulspace"} | relations with one of the given id namespaces of the from reference |
| :from-namespace-prefix | string | "org" | relations with the given id namespace prefix of the from reference |
| :to-namespace | string | "org.soulspace" | relations with the given id namespace of the from reference |
| :to-namespaces | set of strings | #{"org.soulspace"} | relations with one of the given id namespaces of the from reference |
| :to-namespace-prefix | string | "org" | relations with the given id namespace prefix of the from reference |
| :id? | boolean | true, false | elements for which the id check returns the given value |
| :id | keyword | :org.soulspace/overarch | the element with the given id |
| :from | keyword | :org.soulspace/overarch | relations with the given from id |
| :to | keyword | :org.soulspace/overarch | relations with the given to id |
| :subtype? | boolean | true, false | nodes for which the subtype check returns the given value |
| :subtype | keyword | :queue | nodes of the given subtype |
| :subtypes | set of keywords | #{:queue :database} | nodes of one of the given subtypes |
| :external? | boolean | true, false | elements of the given external state |
| :name? | boolean | true, false | elements for which the name check returns the given value |
| :name | string/regex | "Overarch CLI" | elements for which the name matches the given value |
| :desc? | boolean | true, false | elements for which the description check returns the given value |
| :desc | string/regex | "None" "(?i).overarch." | elements for which the description matches the given value |
| :tech? | boolean | true, false | elements for which the technology check returns the given value |
| :tech | string | "Clojure" | elements of the given technology |
| :techs | set of strings | #{"Clojure" "Java"} | elements with one or more of the given technologies |
| :all-techs | set of strings | #{"Clojure" "Java"} | elements with all of the given technologies |
| :tags? | boolean | true, false | elements for which the tags check returns the given value |
| :tag | string | "critical" | elements with the given tag |
| :tags | set of strings | #{"Clojure" "Java"} | elements with one or more of the given tags |
| :all-tags | set of strings | #{"Clojure" "Java"} | elements with all of the given tags |
| :refers? | boolean | true, false | nodes for which the check for refers returns the given value |
| :referred? | boolean | true, false | nodes for which the check for referred returns the given value |
| :refers-to | keyword | :org.soulspace/overarch | nodes which refer to the node with the given id |
| :referred-by | keyword | :org.soulspace/overarch | nodes which are referred by the node with the given id |
| :child? | boolean | true, false | nodes for which the check for child returns the given value |
| :child-of | keyword | :org.soulspace/overarch | nodes which are children of the node with the given id |
| :descendant-of | keyword | :org.soulspace/overarch | nodes which are descendants of the node with the given id |
| :parent? | boolean | true, false | nodes for which the check for children returns the given value |
| :parent-of | keyword | :org.soulspace/overarch | node which is the parent of the node with the given id |
| :ancestor-of | keyword | :org.soulspace/overarch | nodes which are ancestors of the node with the given id |
To show model elements in diagrams or in textual representations you can define different kind of views. The kind of view defines the visual rendering of the elements and the kind of elements and relations that are shown.
In a specific view you can reference the model elements you want to include in this view. A Model element can be included in as many views as you want, but the element has to match the expected kinds of model elements to be shown. For example, a system landscape view renders person and system elements but no use cases or state machines, even if they are referenced in the view. Please consult the models for the model and view elements.
Overarch supports the description of all C4 core and supplementary views except from code views, which ideally should be generated from the code if needed. The core C4 views form a hierarchy of views.
See c4model.com for the rationale and detailed information about the C4 Model.
The views can reference elements from the model as their content. The content of a view should be a list instead of a set because the order of elements may be relevant in the rendering of a view.
| key | type | values | description |
|---|---|---|---|
| :el | keyword | see views | type of the view |
| :id | keyword | namespaced id | used for export file name |
| :title | string | rendered title | |
| :spec | map | see view specs | rendering customization (e.g. styling) |
| :ct | list | model refs (or elements) | view specific keys possible |
Shows the system in the context of the actors and other systems it is interacting with. Contains users, external systems and the system to be described.
Shows the containers (e.g. processes, deployment units of the system) and the interactions between them and the outside world. Contains the elements of the system context diagram and the containers of the system to be described. The system to be described is rendered as a system boundary in the container diagram.
Shows the components and their interactions inside of a container and with outside systems and actors.
A C4 code view is not supported, the level of abstraction for implementation details is usually not high enough to justify modelling implemeted code. Also the speed of change in the code is most likely to high and renders a code model obsolete fast. If you want to visualize existing code, you can use the features of your IDE to generate a diagram of it.
On the other hand it can be useful to create a view of code not yet implemented. An UML class view can be used to model a domain and communicate a design. See UML views for that.
The system landscape view shows a high level picture, a broader view of the system landscape and the interactions of the systems.
The deployment view shows the infrastucture and deployment of the containers of the system.
Shows the order of interactions. The relations get numerated in the given order and the nuber is rendered in the diagram.
Overarch supports selected UML views to show aspects of a system that are not covered by the C4 Model.
A use case view is used to show the actors of the system under design and their goals using this system.
A state machine view is used to show the different states a component can be in. It also shows the transitions between these states based on the input events, the component receives.
A class view is used to show the design of parts of the software. You can use it e.g. to model a domain and to communicate the model with domain experts.
Overarch also supports conceptual views as part of the documentation of the system. Conceptual views can be used in early stages of the development project, when the requirements and the architecture are not yet fixed, to get an overview of the system to be designed. They can also be used to document the relevant concept ofthe domain of the system for discussion, onboarding and learning. Concepts should also be part of the glossary, as well as actors, systems and the applications and containers developed for the system.
The concept view is a graphical view. It shows the concepts as a concept map with the relations between the concepts.
The glossary view is a textual view. It shows a sorted list of elements with their type and their descriptions.
Views can be customized with the :spec key. View specs may include general
directives for a view or directives for specific renderers (e.g. PlantUML).
| key | type | example values | description |
|---|---|---|---|
| :include | keyword | :relations :related | specify automatic includes (work in progress) |
| :selection | map or vector | {:namespace "banking"} | select the content by criteria (see Model Element Selection) |
| :layout | keyword | :top-down, :left-right | rendering direction |
| :linetype | keyword | :orthogonal, :polygonal | different line types for relations |
| :sketch | boolean | true, false | visual clue for sketches |
| :styles | set | see Styling | visual customization of elements |
| :theme | keyword | id of the theme | theme containing styles |
With the :selection key a criteria map or a vector of criterias can be specified.
The matching elements will be included in the view. This feature can be used to
create 'dynamic' views that always contain the latest model content matching
the criteria. See section Model Element Selection by Criteria
for details and banking views for examples.
With the :include key elements can be automatically included in a view.
The default behaviour is :referenced-only which only includes the referenced
elements.
With the value :relations all relations to the referenced elements will be
automatically included.
With the value :related all elements participating in the referenced
relations will be automatically included in addidtion to the referenced
elements.
Criteria based selection, direct element references and includes can be combined in a view. First the selection is merged with the references in such a way, that key overrides and additions on references are preserved. Then the included elements are calculated and merged. This merge also preserves the key overrides and additions made on the references.
Therefore you can select the content with the :selection and :include keys
and customize the rendering with direct references in the :ct vector of the
view.
Overarch supports custom styles for elements. For an example see views.edn.
| key | type | values | description |
|---|---|---|---|
| :id | keyword | namespaced id | used to reference styles |
| :for | keyword | :rel, :element | element type to be styled |
| :line-style | keyword | :dashed, :dotted, :bold | line style for relations |
| :line-color | hex rgb | #0000FF for bright blue | line color for relations |
| :border-color | hex rgb | #FF0000 for bright red | border color for nodes |
| :text-color | hex rgb | #003300 for dark green | text color for names and descriptions |
| :legend-text | string | meaningful text to show in legend |
The specified views C4 architecture and UML viewscan be exported to PlantUML diagrams. These can be rendered into different formats (e.g. SVG, PNG, PDF) with PlantUML.
You can specify PlantUML specific directives with the :plantuml key of a view spec.
:spec {:plantuml {:sprite-libs [:azure]}}
| key | type | example values | description |
|---|---|---|---|
| :node-separation | integer | 50 (for 50 pixels) | separation between nodes |
| :rank-separation | integer | 250 (for 250 pixels) | separation between ranks |
| :sprite-libs | vector | sprite-lib keywords | used to render sprites for techs, order defines precedence of the libs |
| :skinparams | map | {"monochrome" "true"} | render generic skinparams (as skinparam <key> <value>) |
Overarch supports PlantUML sprites to show a visual cue of the technology in the elements of a diagram. It does so by matching the value of the :tech key of a model element to the list of sprites. You can also directly add a :sprite key to the reference of a model element in a view. The explicit :sprite value takes precedence over the :tech value.
The list of sprites contains sprites of the PlantUML standard library, e.g. sprites for AWS and Azure. The mapping files from tech name to sprite reside in resources/plantuml.
Currently the following keys for sprite libs are supported:
- :awslib14
- :azure
- :cloudinsight
- :cloudogu
- :devicons
- :devicons2
- :font-awesome-5
- :logos
The command line interface supports the option --plantuml-list-sprites
which prints the (long) list of sprite mappings.
The Visual Studio Code PlantUML Extension allows previewing and exporting these diagrams right from the IDE.
PlantUML plugins also exists for major IDEs and build tools (e.g. IntelliJ, Eclipse, Maven, Leiningen).
The concept view can be exported as a concept map to a GraphViz *.dot file.
For GraphViz there are a few Visual Studio Code extensions available that allow previews of the generated Graphviz files.
The images can be created with the dot executable, which resides in the bin directory of the GraphViz installation.
You can specify Graphviz directives with the :graphviz key in a view spec. Currently only the configuration of the layout engine is supported.
| key | type | values | description |
|---|---|---|---|
| :engine | keyword | e.g. :dot, :neato, :sfdp | the graphviz layout engine to use |
Markdown is used to render textual representations of the views. You can use converters to generate other formats like HTML or PDF from markdown.
You can specify Markdown directives with the :markdown key in a view spec.
| key | type | values | description |
|---|---|---|---|
| :references | boolean | true, false | render references for nodes |
The model and view descriptions can be exported to JSON to make their content available to languages for which no EDN implementation exists. The export converts each EDN file in the model directory to JSON.
Structurizr is a tool set created by Simon Brown. The Structurizr export creates a workspace with the loaded model and views.
As Structurizr currently only supports the C4 architecture model and views, only these elements will be included in the Structurizr workspace.
Overarch can generate artifacts for model elements via templates. The model elements, to which a template is applied, are selected via criteria. A template can be applied to the collection of selected elements or to each element of the collection.
The use cases of the tempates range from reports up to automatic code generation.
Overarch supports forward engineering protected areas for manually written content in generated artifacts
You can configure the generation of artifacts with an EDN file. The configuration contains a vector of generation context maps. A generation context map specifies a selection of model elements, a template to use, how the template should be applied, and where the resulting artifact should be created.
| key | type | values | default | description |
|---|---|---|---|---|
| :selection | CRITERIA | {:el :system} | Criteria to select model elements | |
| :template | PATH | "report/node.cmb" | Path to the template relative to the template dir | |
| :engine | :keyword | :comb | :comb | The template engine to use (currently just :comb) |
| :encoding | string | "UTF-8" | "UTF-8" | The encoding of the result artifact |
| :per-element | boolean | true/false | false | Apply the template for each element of the selection or on the selection as a whole |
| :subdir | string | "report" | Subdirectory for generated artifact under the generator directory | |
| :namespace-prefix | string | "src" | Prefix to the namespace to use as path element | |
| :base-namespace | string | Base namespace to use as path element | ||
| :namespace-suffix | string | "impl" | Suffix to the namespace to use as path element | |
| :prefix | string | "Abstract" | Prefix for the filename | |
| :base-name | string | Base of the filename | ||
| :suffix | string | "Impl" | Suffix for the filename | |
| :extension | string | "md" "clj" "java" | Extension for the filename | |
| :filename | string | "README.md" | Specific filename to use | |
| :id-as-namespace | boolean | true/false | false | Use the element id as the namespace for path generation |
| :protected-areas | string | "PA" | Marker for protected areas in the template/artifact |
[;; Report for all systems in the banking namespace
{:selection {:namespace "banking" :el :system} ; selection criteria for the model elements
:template "node-report.md.cmb" ; relative path of the template to apply
:title "Banking Systems Report" ; title of the report
:engine :comb ; the template engine to use (currently only :comb)
:encoding "UTF-8" ; artifact encoding
:per-element false ; apply the template for each element of the selection or on the selection as a whole
:subdir "reports" ; subdirectory for generated artifact
; :namespace-prefix "" ; prefix for the namespace of the generated artifact
:base-namespace "systems" ; base namespace of the generated artifact
; :namespace-suffix "" ; suffix for the namespace of the generated artifact
; :prefix "" ; prefix for the name of the generated artifact
:base-name "systems-report" ; base name of the generated artifact
; :suffix "" ; suffix for the name of the generated artifact
:extension "md" ; extension of the generated artifact
:id-as-namespace false ; use the name as the namespace of the artifact
; :protected-area "PA" ; protected area prefix
}
;; Report for the REST interfaces in the model
{:selection {:el :model-relation :techs #{"REST"}} ; selection criteria for the model elements
:template "rel-report.md.cmb" ; relative path of the template to apply
:title "REST Interface Report" ; title of the report
:engine :comb ; the template engine to use (currently only :comb)
:encoding "UTF-8" ; artifact encoding
:per-element false ; apply the template for each element of the selection or on the selection as a whole
:subdir "reports" ; subdirectory for generated artifact
; :namespace-prefix "" ; prefix for the namespace of the generated artifact
:base-namespace "interfaces" ; base namespace of the generated artifact
; :namespace-suffix "" ; suffix for the namespace of the generated artifact
; :prefix "" ; prefix for the name of the generated artifact
:base-name "systems-report" ; base name of the generated artifact
; :suffix "" ; suffix for the name of the generated artifact
:extension "md" ; extension of the generated artifact
:id-as-namespace false ; use the name as the namespace of the artifact
; :protected-area "PA" ; protected area prefix
}]The relevant CLI options for template based artifact generation are
-m, --model-dir PATH models Models directory or path
-t, --template-dir DIRNAME templates Template directory
-g, --generation-config FILE Generation configuration
-G, --generation-dir DIRNAME generated Generation artifact directory
-B, --backup-dir DIRNAME backup Generation backup directory
Example using a config file in the current directory and default directories
java -jar overarch.jar -g gencfg.edn
Overarch incorporates the Comb template engine by James Reeves.
Comb is a simple templating system for Clojure. You can use Comb to embed fragments of Clojure code into a text file.
Some example templates can be found in the templates folder.
Clojure fragments in a template are demarkated with <% and %>.
You can embed clojure code as an expression, where the result of the
execution is included in the resulting artifact. You can also embed the clojure
code as a control structure, where the result of the execution of the control
structure is not included in the resulting artifact, only the template text or
other expressions inside of the control structure.
1 + 2 = <%= (+ 1 2) %>Result:
1 + 2 = 3
foo<% (dotimes [x 3] %> bar<%) %>Result:
foo bar bar bar
Comb templates can contain arbitrary clojure code, which gets evaluated in the context of the overarch process. Be aware of this fact and review templates accordingly, especially when using templates from external sources.
Protected areas are used to protect manually inserted text in generated artifacts. For example, when generating source code from a code model element, maybe only the signature of the function may be generated. The body of the function may have to be inserted by a programmer.
When regenerating the source code artifact, you don't want the manually inserted code to be deleted or overridden, but preserved.
Given this class node from a model
{:el :class
:id :model/calc
:name "Calc"
:ct [{:el method
:name "square"
:type "double"
:visibility :public
:ct [{:el :field
:name "x"
:type "double"}
]}
]}and a template like
public class <%= (:name e) %> {
<% (doseq [m (:ct e)] %>
public <%= (:type m) %> <%= (:name m) %>(<%
(doseq [p (:ct m)] %> (:type m) %> <%= (:name m) %>, <%)%>) {
// PA-BEGIN(square-impl)
<%= (:square-impl protected-areas)%>
// PA-END(square-impl)
}
<%)%>
}On the first generation pass, the generated file will look like
public class Calc {
public double square(double x) {
// PA-BEGIN(square-impl)
// PA-END(square-impl)
}
}After manually inserting the implementation, the artifact looks like
public class Calc {
public double square(double x) {
// PA-BEGIN(square-impl)
return x * x;
// PA-END(square-impl)
}
}On regeneration, the content of the protected area is parsed by the generator before applying the template and reinserted by the template.
So after regeneration the artifact still looks like
public class Calc {
public double square(double x) {
// PA-BEGIN(square-impl)
return x * x;
// PA-END(square-impl)
}
}Overarch CLI
Reads your model and view specifications and renders or exports
into the specified formats.
For more information see https://github.com/soulspace-org/overarch
Usage: java -jar overarch.jar [options].
Options:
-m, --model-dir PATH models Models directory or path
-r, --render-format FORMAT Render format (all, graphviz, markdown, plantuml)
-R, --render-dir DIRNAME export Render directory
--[no-]render-format-subdirs true Use subdir per render format
-x, --export-format FORMAT Export format (json, structurizr)
-X, --export-dir DIRNAME export Export directory
-w, --watch false Watch model dir for changes and trigger action
-s, --select-elements CRITERIA Select and print model elements by criteria
-S, --select-references CRITERIA Select model elements by criteria and print as references
-T, --template-dir DIRNAME templates Template directory
-g, --generation-config FILE Generation configuration
-G, --generation-dir DIRNAME generated Generation artifact directory
-B, --backup-dir DIRNAME backup Generation backup directory
--[no-]model-warnings true Returns warnings for the loaded model
--[no-]model-info false Returns infos for the loaded model
--plantuml-list-sprites false Lists the loaded PlantUML sprites
-h, --help Print help
--debug false Print debug messages
To render all views for all models, use
> java -jar ./target/overarch.jar -r all
or
> java -jar ./target/overarch.jar -r all --debug
To render all views for all models with a directory watch to trigger rerendering on changes, use
> java -jar ./target/overarch.jar -r all -w --debug
To export the models to JSON, use
> java -jar ./target/overarch.jar -x json
To query the model for all containers, use
> java -jar ./target/overarch.jar -s '{:el :container}'
or
> java -jar ./target/overarch.jar -S '{:el :container}'