A name that stands for several layers at once
Draw items on a name that follows several layers, and say what a reader must find true of them before it shows what the name covers.
Summary
Layers are shown and hidden one by one. A rule is a name that watches several of them: show this warning while every safety layer is on, show that note as soon as any language layer is off. Items drawn on the rule follow it, and a reader works the rule out from the layers themselves rather than from a switch of its own.
Technically
Written at the top level of a request, under
"layer_rules"
layer_rules writes the visibility expressions of the document: a membership dictionary naming several layers and the policy that decides them. An item drawn on the rule's name follows the rule. The name sits beside the declared layers, so a rule taking the name of a layer the request declared is refused.
Request schema
-
layer_rules— array, optional, empty by default. -
layer_rules[].name— string, required. The name items say they are drawn on. It must not be the name of a declared layer. -
layer_rules[].shown— object, required.layers— array of strings, the declared layers the rule follows;policy— one ofall_visible,any_visible,any_hidden,all_hidden.
A rule decides what is shown, never what is printed: what goes on paper is settled by each layer's own entry under layers.
A whole request that draws it
{
"layers": {
"french": { "name": "French" },
"safety": { "name": "Safety" }
},
"layer_rules": [
{
"name": "french-safety",
"shown": { "layers": ["french", "safety"], "policy": "all_visible" }
}
],
"standard_fonts": [{ "name": "sans", "face": "helvetica" }],
"items": [
{
"type": "text",
"rect": { "llx": 60, "lly": 740, "urx": 535, "ury": 765 },
"content": ["A warning shown while both layers are on"],
"font": "sans",
"font_size": 14
}
]
}What is drawn, and how it comes out
Everything that can be drawn on a page The file's weight and the time it takes Sheets a reader shows or hides A drawing made once, shown by a button The sets of layers a reader offers
Where to go next
Every key of a request, in one page The other forty-one settings of a request