stash

frontend/src/label.js

@@ -1,6 +1,7 @@
 import {loadAnyDCode} from "../vendor/anyd-qr.js";
 import {encodeHandleForUrl} from "@/router"
 import {drawPixelText, preloadPixelFontRenderer} from "@/pixel-font.js";
+import {DERIVED_VARS} from "@/label-layouts.js";
 
 // Re-exported so every caller can preload both the QR encoder and the bitmap-font rasterizer
 // (see fontTierFor's `pixel` tiers below) the same way, alongside this file's own preloadQrEncoder.
@@ -349,7 +350,7 @@ function measureTextBlock(ctx, lines, referencePx) {
     return {width, height};
 }
 
-// Converts a resolved content tree (see label-layouts.js's resolveContent) into one ready for layout. See
+// Converts a resolved content tree (see templateContent below) into one ready for layout. See
 // docs/implementation.md#render-tree-construction.
 function buildRenderTree(ctx, node, referencePx) {
     if (isSplit(node)) {
@@ -483,7 +484,7 @@ function layoutContent(ctx, content, fixedSize, maxLength, referencePx, pxPerMm,
     return {tree, length, warnings, qrInfo, textInfo};
 }
 
-// The tape-fed layout: draws a fully resolved content tree (see label-layouts.js's resolveContent) at the tape's
+// The tape-fed layout: draws a fully resolved content tree (see templateContent below) at the tape's
 // real pixel dimensions. See docs/implementation.md#tape-fed-label-drawing. Returns
 // {textSizesPx}: each "text" leaf's effective font size, in the tree's own left-to-right,
 // top-to-bottom order; {warnings}: {short, message} scan-reliability entries from
@@ -627,3 +628,54 @@ export function buildLabelFields(prefill) {
     const build = LABEL_FIELD_BUILDERS[prefill.kind];
     return build ? build(prefill.components) : {};
 }
+
+// Runs each DERIVED_VARS calc against `fields`, adding the result wherever its inputs are
+// present, so callers never need to know DERIVED_VARS' {inputs, calc} shape.
+export function withDerivedVars(fields) {
+    const result = {...fields};
+    for (const [name, {inputs, calc}] of Object.entries(DERIVED_VARS)) {
+        if (inputs.every(v => result[v])) {
+            result[name] = calc(result);
+        }
+    }
+    return result;
+}
+
+function walkLeaves(node, fn) {
+    if (Array.isArray(node)) {
+        node.forEach(child => walkLeaves(child, fn));
+    } else {
+        fn(node);
+    }
+}
+
+function mapTree(node, fn) {
+    return Array.isArray(node) ? node.map(child => mapTree(child, fn)) : fn(node);
+}
+
+// Resolved only if every part is - a single string for a QR-family/"text" leaf, every line for a
+// multi-line "text" (see label-layouts.js's "owner-id-text" and "item-url-qr-owner-id" templates).
+function isResolved(value) {
+    return Array.isArray(value) ? value.every(isResolved) : value !== undefined && value !== null;
+}
+
+// Shared by LabelLayoutPreview.vue's grid and Print.vue's preview, so neither reimplements
+// leaf-walking/field-resolving itself.
+export function templateIsAvailable(t, fields) {
+    let available = true;
+    walkLeaves(t.layout, leaf => {
+        if (leaf.type !== "empty" && !isResolved(leaf.content(fields))) {
+            available = false;
+        }
+    });
+    return available;
+}
+
+export function templateContent(t, fields) {
+    if (!templateIsAvailable(t, fields)) {
+        const err = new Error("This layout needs more fields filled in before it can be drawn.");
+        err.short = "missing data";
+        throw err;
+    }
+    return mapTree(t.layout, leaf => leaf.type === "empty" ? leaf : {...leaf, value: leaf.content(fields)});
+}