Components and connections

Placing and arranging components#

• Add: drag a component from the Components drawer onto the canvas to place it exactly, tap or click it (or press Enter on it) to add it in the middle of what you are looking at, or type add backend api in the terminal. The drawer can collapse to a rail of icons (every icon can be dragged or tapped) to give the canvas more room. On a tablet the rail is always there and the full list opens over the canvas; the script panel does the same from View → Script panel. On a phone, tap Edit, then Add to pick a component from a searchable list.
• Move: drag it. Components snap to the canvas grid; View → Snap all to grid tidies an older diagram in one step.
• Select several: Shift-drag a selection box, or Ctrl/Cmd-click to add to the selection.
• Copy and paste: Ctrl+C, Ctrl+X, Ctrl+V use the system clipboard, so you can paste into another diagram or another tab. Ctrl+D duplicates in place. Pasted copies get fresh ids, and connections between copied components come with them.
• Delete: select and press Delete or Backspace. Connections to a deleted component go with it.
• Find it again: double-click a component to centre and zoom the view on it.
• Undo: Ctrl+Z and Ctrl+Shift+Z (or Ctrl+Y) step through your changes. A whole terminal script is a single undo step.

Editing a component’s settings#

Every component card lists its settings. Click a value to edit it; numbers, true/false switches and fixed choices (like a database engine) each get the right kind of input. Hover a setting’s name for a one-line explanation. The same values live in the Script panel as JSON and in the terminal as set api requestsPerSec=500 — all three stay in sync.

Each component has an id (like backend-1) that is unique in the diagram. Ids are how connections and terminal commands refer to components. You can rename one in the terminal with rename backend-1 api; its connections follow.

Connections#

A connection says “these two components talk to each other”. Draw one by dragging from a component’s edge onto another component, or with connect web -> api -> db in the terminal. Drawing the same connection twice (same two components, same direction) is quietly skipped.

• Direction does not matter to Rule-based playback. Which way you dragged is an accident of where you started; the walk follows a connection from either end. A request goes out along it and the response comes back the same way.
• Right-click a connection to open its settings. Order is which of a component’s several connections Rule-based playback tries first (lower runs first). Direction (forward, backward, both) only affects Default playback, where markers animate along the line.
• Delete a connection by selecting it and pressing Delete, from its right-click menu, or with disconnect web -> api.
• Double-click a connection to zoom in on both of its ends.

Groups and replication groups#

Groups are a purely visual box around components that belong together (a “data tier”, a “region”). Select two or more components and press Ctrl+G or the Group button that appears. A group has a label, can be resized, and Ungroup removes the box without touching its members. A group is never a connection endpoint — you connect the components inside it.

Replication groups create several identical components at once, already grouped: select a component and press Create Replication Group… to make between 2 and 20 copies with the same type and settings. Dragging a connection onto a group’s empty area connects the dragged component to every member of the group in one go.

Starter templates#

File → Templates… opens a gallery of ready-made diagrams. Hover a card for Add, Preview and Start new diagram.

• Add puts the template into the diagram you have open, to the right of what is already there, with its components selected so you can drag them wherever you like. Nothing you made is touched. You can add as many templates as you want, in any order, to combine them — and one Undo takes away the last one.
• In a diagram you are sharing, adding a template is just another edit: everyone in it sees the new components appear, and nobody leaves or loses their place. A diagram saved to the cloud is limited to the number of components your plan allows; if a template would not fit, Diagravo tells you before changing anything.
• Start new diagram replaces the canvas with the template as a brand-new, unsaved diagram. If you have unsaved changes it asks first. The diagram you were in is not changed.

Custom icons#

Signed-in users can replace a component type’s icon with their own image from account menu → Custom icons. Published share links carry the custom icons so viewers see your diagram the way you drew it, and so do people you invite to it: they see the owner’s icons on the canvas, while their own palette keeps their own.

Component types#

Diagravo has 35 component types in 9 groups. The tables list what each one models, the names you can type for it in the terminal, and the settings it starts with (the same values a freshly dragged component gets).

All settings#

Every setting name in the product, with what it means and which components have it. Settings marked “informational only” do not affect playback.