Extend build script to support cross references for icon and icons

README.md

@@ -152,6 +152,10 @@ data/
 
 The format for each file is defined in the [`schemas`](schemas) directory.
 
+#### Preset categories
+
+Files in `data/preset_categories/` (the `categories/` folder in the tree above) define preset groups in the editor. Each JSON file requires `name`, `icon`, and `members`. See the [icons subpage](ICONS.md) for icon ids.
+
 ### Presets
 
 A [preset](https://wiki.openstreetmap.org/wiki/Preset) represents a specific type of
@@ -329,6 +333,10 @@ This can be overwritten by adding the field explicitly like `"fields": [ "shop",
 
 An icon representing a preset, e.g. `"icon": "temaki-power_tower"` ([Example](https://github.com/openstreetmap/id-tagging-schema/blob/main/data/presets/power/tower.json)). More information about available icon sets and usage of icons can be found on the [icons subpage](ICONS.md).
 
+You may set `"icon": "{presets/<preset-id>}"`, e.g. `{presets/shop/books}` for `data/presets/shop/books.json` (or `_books.json`, see [`searchable`](#searchable)). Only `presets/*` is allowed (not `fields/*`). Chains are OK and will also get resolved during build.
+
+For icons on each combo or radio option, see [`icons`](#icons).
+
 ##### `imageURL`
 
 The URL of a remote image file. This does not fully replace `icon`—both may be shown in the UI.
@@ -729,7 +737,11 @@ For `identifier` fields, the regular expression that valid values are expected t
 
 ##### `icons`
 
-For combo and radio fields, the `icons` object might contain the name of icons which represent the different values of the field. More information about available icon sets and usage of icons can be found on the [icons subpage](ICONS.md).
+On [combo / dropdown](#combodropdown-fields) and [radio](#radio-buttons) fields, the `icons` object maps each option key to an icon id shown beside that value in the editor, e.g. `"zebra": "iD-crossing_markings-zebra"` in the snippet below. More information about available icon sets and usage of icons can be found on the [icons subpage](ICONS.md).
+
+You may set each value to `"{presets/<preset-id>}"` instead of a literal id, with the same rules as [preset `icon`](#icon).
+
+To copy an entire `icons` map from another field, use [`iconsCrossReference`](#iconscrossreference).
 
 Combo field types can accept key-label pairs in the `options` value of the `strings` property.
 
@@ -739,7 +751,7 @@ Combo field types can accept key-label pairs in the `options` value of the `stri
     "type": "combo",
     "label": "Crossing Markings",
     "icons": {
-        "zebra": "iD-crossing_markings-zebra",
+        "zebra": "{presets/highway/footway/crossing/zebra}",
         "lines": "iD-crossing_markings-lines",
         …
     }
@@ -748,7 +760,9 @@ Combo field types can accept key-label pairs in the `options` value of the `stri
 
 ##### `iconsCrossReference`
 
-An optional property to reference to the icons of another field, indicated  by using that field's name contained in brackets, like `{field}`. This is for example useful when there are multiple variants of fields for the same tag, which should all use the same icons.
+An optional property to copy the entire `icons` object from another field by giving that field's id in brackets (no `presets/` prefix)—for example `{kerb}` copies the field whose id is `kerb`. Useful when several field variants share the same option icons.
+
+If a field uses `iconsCrossReference`, the builder copies the other field’s `icons` map first, then expands every `{presets/…}` value in **all** field `icons` maps (including the copy). 
 
 ### Deprecations
 

lib/build.js

@@ -122,7 +122,7 @@ function processData(options, type) {
   let fields = generateFields(dataDir, tstrings, searchableFieldIDs, references);
   if (options.processFields) options.processFields(fields);
 
-  let presets = generatePresets(dataDir, tstrings, searchableFieldIDs, options.listReusedIcons, references);
+  let presets = generatePresets(dataDir, tstrings, searchableFieldIDs, references);
   if (options.processPresets) options.processPresets(presets);
 
   // Additional consistency checks
@@ -131,6 +131,8 @@ function processData(options, type) {
 
   dereferenceUntranslatedContent(presets, fields);
 
+  reportReusedIcons(presets, options.listReusedIcons);
+
   const defaults = read(dataDir + '/preset_defaults.json');
   if (defaults) {
     validateSchema(dataDir + '/preset_defaults.json', defaults, defaultsSchema);
@@ -338,10 +340,57 @@ function stripLeadingUnderscores(str) {
 }
 
 
-function generatePresets(dataDir, tstrings, searchableFieldIDs, listReusedIcons, references) {
-  let presets = {};
+/**
+ * @param {Record<string, object>} presets
+ * @param {boolean | number} listReusedIcons
+ */
+function reportReusedIcons(presets, listReusedIcons) {
+  if (!listReusedIcons) return;
+
+  const icons = {};
+  for (const id in presets) {
+    const preset = presets[id];
+    if (preset.searchable !== false) {
+      const icon = preset.icon || '(none)';
+      if (!icons[icon]) icons[icon] = [];
+      icons[icon].push(id);
+    }
+  }
+
+  const reuseLimit = typeof listReusedIcons === 'number' && listReusedIcons > 0 ? listReusedIcons : 1;
 
-  let icons = {};
+  let reusedIconPresetCount = 0;
+  const reusedIcons = Object.keys(icons).filter(function(iconID) {
+    const presetIDs = icons[iconID];
+    if (presetIDs.length > reuseLimit) {
+      reusedIconPresetCount += presetIDs.length;
+      return true;
+    }
+    return false;
+  });
+
+  if (reusedIcons.length > 0) {
+    process.stdout.write(reusedIcons.length + ' icon(s), including (none), are each used more than ' + reuseLimit + ' time(s), affecting ' + reusedIconPresetCount + ' presets\n');
+
+    reusedIcons.sort(function(iconID1, iconID2) {
+      return icons[iconID2].length - icons[iconID1].length;
+
+    }).forEach(function(iconID) {
+      const presetIDs = icons[iconID];
+      process.stdout.write(iconID + ', ' + presetIDs.length + '\n');
+      for (let i in presetIDs) {
+        process.stdout.write('-' + presetIDs[i] + '\n');
+      }
+      process.stdout.write('\n');
+    });
+  } else {
+    process.stdout.write(styleText('green', 'No icon is used more than ' + reuseLimit + ' time(s) across all searchable presets\n'));
+  }
+}
+
+
+function generatePresets(dataDir, tstrings, searchableFieldIDs, references) {
+  let presets = {};
 
   fs.globSync(dataDir + '/presets/**/*.json', {
     posix: true,
@@ -398,46 +447,8 @@ function generatePresets(dataDir, tstrings, searchableFieldIDs, listReusedIcons,
     }
 
     presets[id] = preset;
-
-    if (preset.searchable !== false) {
-      let icon = preset.icon || '(none)';
-      if (!icons[icon]) icons[icon] = [];
-      icons[icon].push(id);
-    }
   });
 
-  if (listReusedIcons) {
-    const reuseLimit = typeof listReusedIcons === 'number' && listReusedIcons > 0 ? listReusedIcons : 1;
-
-    let reusedIconPresetCount = 0;
-    const reusedIcons = Object.keys(icons).filter(function(iconID) {
-      const presetIDs = icons[iconID];
-      if (presetIDs.length > reuseLimit) {
-        reusedIconPresetCount += presetIDs.length;
-        return true;
-      }
-      return false;
-    });
-
-    if (reusedIcons.length > 0) {
-      process.stdout.write(reusedIcons.length + ' icon(s), including (none), are each used more than ' + reuseLimit + ' time(s), affecting ' + reusedIconPresetCount + ' presets\n');
-
-      reusedIcons.sort(function(iconID1, iconID2) {
-        return icons[iconID2].length - icons[iconID1].length;
-
-      }).forEach(function(iconID) {
-        const presetIDs = icons[iconID];
-        process.stdout.write(iconID + ', ' + presetIDs.length + '\n');
-        for (let i in presetIDs) {
-          process.stdout.write('-' + presetIDs[i] + '\n');
-        }
-        process.stdout.write('\n');
-      });
-    } else {
-      process.stdout.write(styleText('green', 'No icon is used more than ' + reuseLimit + ' time(s) across all searchable presets\n'));
-    }
-  }
-
   return presets;
 }
 

lib/references.js

@@ -3,10 +3,112 @@ export function isReference(string) {
   return string.startsWith('{') && string.endsWith('}');
 }
 
+/**
+ * Resolve "{presets/<id>}" to a concrete icon id (following chains). Only
+ * `presets/` is valid for icons; `{fields/…}` and bare `{id}` throw.
+ *
+ * @param {Record<string, { icon?: string }>} presets
+ * @param {string} ref
+ * @param {string} contextMessage
+ * @param {Set<string>} [visitedPresetIds]
+ * @returns {string}
+ */
+function resolveIconRefToId(presets, ref, contextMessage, visitedPresetIds = new Set()) {
+  if (!isReference(ref)) return ref;
+
+  const inner = ref.slice(1, -1);
+  const slashIdx = inner.indexOf('/');
+  if (slashIdx === -1) {
+    throw new Error(
+      `Invalid icon reference “${ref}” in ${contextMessage}: use “{presets/<preset-id>}” (with a “presets/” prefix).`,
+    );
+  }
+
+  const type = inner.slice(0, slashIdx);
+  const id = inner.slice(slashIdx + 1);
+
+  if (type === 'fields') {
+    throw new Error(
+      `Invalid icon reference “${ref}” in ${contextMessage}: icon references must use “{presets/<preset-id>}”, not “{fields/…}”.`,
+    );
+  }
+  if (type !== 'presets') {
+    throw new Error(
+      `Invalid icon reference “${ref}” in ${contextMessage}: only “{presets/<preset-id>}” is allowed (unexpected prefix “${type}/”).`,
+    );
+  }
+  if (!id) {
+    throw new Error(
+      `Invalid icon reference “${ref}” in ${contextMessage}: missing preset id after “presets/”.`,
+    );
+  }
+
+  if (visitedPresetIds.has(id)) {
+    throw new Error(
+      `Cycle detected while resolving icon reference “${ref}” in ${contextMessage}: preset “${id}” appears more than once in the chain.`,
+    );
+  }
+  visitedPresetIds.add(id);
+
+  const referenced = presets[id];
+  if (!referenced) {
+    throw new Error(
+      `Cannot resolve icon reference “${ref}” in ${contextMessage}: there is no preset “${id}”.`,
+    );
+  }
+
+  const next = referenced.icon;
+  if (next === undefined || next === null || next === '') {
+    throw new Error(
+      `Cannot resolve icon reference “${ref}” in ${contextMessage}: preset “${id}” has no “icon” property.`,
+    );
+  }
+
+  if (isReference(next)) {
+    return resolveIconRefToId(presets, next, contextMessage, visitedPresetIds);
+  }
+  return next;
+}
+
+/**
+ * @param {Record<string, { icon?: string }>} presets
+ * @param {Record<string, { icons?: Record<string, string> }>} fields
+ */
+function dereferencePresetIconStrings(presets, fields) {
+  for (const presetID in presets) {
+    const preset = presets[presetID];
+    if (typeof preset.icon === 'string' && isReference(preset.icon)) {
+      preset.icon = resolveIconRefToId(
+        presets,
+        preset.icon,
+        `preset “${presetID}” icon`,
+      );
+    }
+  }
+
+  for (const fieldID in fields) {
+    const field = fields[fieldID];
+    if (!field.icons || typeof field.icons !== 'object') continue;
+    for (const key of Object.keys(field.icons)) {
+      const v = field.icons[key];
+      if (typeof v === 'string' && isReference(v)) {
+        field.icons[key] = resolveIconRefToId(
+          presets,
+          v,
+          `field “${fieldID}” icons.${key}`,
+        );
+      }
+    }
+  }
+}
+
 /**
  * This is only used to expand references to _untranslated content_.
  * For example, `fields` can reference the list of field IDs from another
  * preset.
+ *
+ * @param {Record<string, object>} presets
+ * @param {Record<string, object>} fields
  */
 export function dereferenceUntranslatedContent(presets, fields) {
   for (const presetID in presets) {
@@ -98,6 +200,9 @@ export function dereferenceUntranslatedContent(presets, fields) {
       delete field.locationSetCrossReference;
     }
   }
+
+  // 11. preset `icon` and field `icons` values may use "{presets/<id>}" for another preset's icon id
+  dereferencePresetIconStrings(presets, fields);
 }
 
 /**

schemas/field.json

@@ -359,15 +359,15 @@
             "enum": ["preset", "changeset", "manual", "group"]
         },
         "icons": {
-            "description": "For combo and radio fields: Name of icons which represents different values of this field",
+            "description": "For combo and radio fields: Name of icons which represents different values of this field. Values may be icon ids or \"{presets/<preset-id>}\".",
             "type": "object",
             "minProperties": 1,
             "additionalProperties": {
                 "type": "string"
             }
         },
         "iconsCrossReference": {
-            "description": "A field can reference icons of another by using that field's identifier contained in brackets, like {field}.",
+            "description": "Copy the entire icons map from another field using that field's id in brackets, e.g. {other_field}.",
             "type": "string"
         }
     },

schemas/preset.json

@@ -59,7 +59,7 @@
             }
         },
         "icon": {
-            "description": "Name of preset icon which represents this preset",
+            "description": "Name of preset icon which represents this preset, or cross-reference with \"{presets/<preset-id>}\".",
             "type": "string"
         },
         "imageURL": {

schemas/preset_category.json

@@ -10,7 +10,7 @@
             "type": "string"
         },
         "icon": {
-            "description": "Name of preset icon which represents this preset",
+            "description": "Name of preset icon which represents this category",
             "type": "string"
         },
         "members": {