Added mechanism for displaying fields conditionally based on tags

data/presets/README.md

@@ -233,6 +233,26 @@ For number fields, the lowest valid value. There is no default.
 
 For number fields, the greatest valid value. There is no default.
 
+##### `prerequisiteTag`
+
+An object defining the tags the feature needs before this field will be displayed. It must have this property:
+
+- `key`: The key for the required tag.
+
+And may optionally have one of these properties:
+
+- `value`: The value that the key must have.
+- `valueNot`: The value that the key must not have.
+
+For example, this is how we show the Internet Access Field only if the feature has an `internet_access` tag not equal to `no`.
+
+```js
+"prerequisiteTag": {
+    "key": "internet_access",
+    "valueNot": "no"
+}
+```
+
 ## Icons
 
 You can use any of the following open source map icon sets as preset icons.

data/presets/fields.json

@@ -74,7 +74,7 @@
     "dance/style": {"key": "dance:style", "type": "semiCombo", "label": "Dance Styles"},
     "date": {"key": "date", "type": "check", "label": "Date"},
     "delivery": {"key": "delivery", "type": "check", "label": "Delivery"},
-    "denomination": {"key": "denomination", "type": "combo", "label": "Denomination"},
+    "denomination": {"key": "denomination", "type": "combo", "label": "Denomination", "prerequisiteTag": {"key": "religion"}},
     "denotation": {"key": "denotation", "type": "combo", "label": "Denotation"},
     "description": {"key": "description", "type": "textarea", "label": "Description", "universal": true},
     "design": {"key": "design", "type": "combo", "label": "Design"},
@@ -147,8 +147,8 @@
     "inscription": {"key": "inscription", "type": "textarea", "label": "Inscription"},
     "intermittent": {"key": "intermittent", "type": "check", "label": "Intermittent"},
     "internet_access": {"key": "internet_access", "type": "combo", "label": "Internet Access", "strings": {"options": {"yes": "Yes", "no": "No", "wlan": "Wifi", "wired": "Wired", "terminal": "Terminal"}}},
-    "internet_access/fee": {"key": "internet_access:fee", "type": "check", "label": "Internet Access Fee"},
-    "internet_access/ssid": {"key": "internet_access:ssid", "type": "text", "label": "SSID (Network Name)"},
+    "internet_access/fee": {"key": "internet_access:fee", "type": "check", "label": "Internet Access Fee", "prerequisiteTag": {"key": "internet_access", "valueNot": "no"}},
+    "internet_access/ssid": {"key": "internet_access:ssid", "type": "text", "label": "SSID (Network Name)", "prerequisiteTag": {"key": "internet_access", "valueNot": "no"}},
     "kerb": {"key": "kerb", "type": "combo", "label": "Curb"},
     "label": {"key": "label", "type": "textarea", "label": "Label"},
     "lamp_type": {"key": "lamp_type", "type": "combo", "label": "Type"},

data/presets/fields/denomination.json

@@ -1,5 +1,8 @@
 {
     "key": "denomination",
     "type": "combo",
-    "label": "Denomination"
-}
+    "label": "Denomination",
+    "prerequisiteTag": {
+        "key": "religion"
+    }
+}

data/presets/fields/internet_access/fee.json

@@ -1,5 +1,9 @@
 {
     "key": "internet_access:fee",
     "type": "check",
-    "label": "Internet Access Fee"
+    "label": "Internet Access Fee",
+    "prerequisiteTag": {
+        "key": "internet_access",
+        "valueNot": "no"
+    }
 }

data/presets/fields/internet_access/ssid.json

@@ -1,5 +1,9 @@
 {
     "key": "internet_access:ssid",
     "type": "text",
-    "label": "SSID (Network Name)"
+    "label": "SSID (Network Name)",
+    "prerequisiteTag": {
+        "key": "internet_access",
+        "valueNot": "no"
+    }
 }

data/presets/schema/field.json

@@ -129,6 +129,28 @@
         "maxValue": {
             "description": "Maximum field value (number fields only)",
             "type": "integer"
+        },
+        "prerequisiteTag": {
+            "description": "Tagging constraint for showing this field in the editor",
+            "type": {
+                "type": "object",
+                "properties": {
+                    "key": {
+                        "description": "The key of the required tag",
+                        "type": "string",
+                        "required": true
+                    },
+                    "value": {
+                        "description": "The value that the tag must have. (alternative to 'valueNot')",
+                        "type": "string"
+                    },
+                    "valueNot": {
+                        "description": "The value that the tag cannot have. (alternative to 'value')",
+                        "type": "string"
+                    }
+                },
+                "additionalProperties": false
+            }
         }
     },
     "additionalProperties": false

modules/ui/field.js

@@ -40,10 +40,13 @@ export function uiField(context, presetField, entity, options) {
             dispatch.call('change', field, t, onInput);
         });
 
-    // if this field cares about the entity, pass it along
-    if (entity && field.impl.entity) {
+    if (entity) {
         field.entityID = entity.id;
-        field.impl.entity(entity);
+
+        // if this field cares about the entity, pass it along
+        if (field.impl.entity) {
+            field.impl.entity(entity);
+        }
     }
 
     field.keys = field.keys || [field.key];
@@ -206,6 +209,11 @@ export function uiField(context, presetField, entity, options) {
     };
 
 
+    field.hasValue = function() {
+        return _some(field.keys, function(key) { return !!_tags[key]; });
+    };
+
+
     field.show = function() {
         _show = true;
         if (field.default && field.key && _tags[field.key] !== field.default) {
@@ -215,9 +223,38 @@ export function uiField(context, presetField, entity, options) {
         }
     };
 
-
+    // A shown field has a visible UI, a non-shown field is in the 'Add field' dropdown
     field.isShown = function() {
-        return _show || _some(field.keys, function(key) { return !!_tags[key]; });
+        return _show || field.hasValue();
+    };
+
+    // An allowed field can appear in the UI or in the 'Add field' dropdown.
+    // A non-allowed field is hidden from the user altogether
+    field.isAllowed = function() {
+
+        if (field.hasValue()) {
+            // always allow a field with a value to display
+            return true;
+        }
+
+        var prerequisiteTag = field.prerequisiteTag;
+        if (prerequisiteTag && field.entityID) {
+            if (prerequisiteTag.key) {
+                var value = context.graph().entity(field.entityID).tags[prerequisiteTag.key];
+                if (value) {
+                    if (prerequisiteTag.valueNot) {
+                        return prerequisiteTag.valueNot !== value;
+                    }
+                    if (prerequisiteTag.value) {
+                        return prerequisiteTag.value === value;
+                    }
+                    return true;
+                } else {
+                    return false;
+                }
+            }
+        }
+        return true;
     };
 
 

modules/ui/form_fields.js

@@ -14,9 +14,18 @@ export function uiFormFields(context) {
     }
 
 
+    formFields.tagsChanged = function() {};
+
     function render(selection, klass) {
-        var shown = _fieldsArr.filter(function(field) { return field.isShown(); });
-        var notShown = _fieldsArr.filter(function(field) { return !field.isShown(); });
+
+        formFields.tagsChanged = function() {
+            render(selection, klass);
+        };
+
+        var allowedFields = _fieldsArr.filter(function(field) { return field.isAllowed(); });
+
+        var shown = allowedFields.filter(function(field) { return field.isShown(); });
+        var notShown = allowedFields.filter(function(field) { return !field.isShown(); });
 
         var container = selection.selectAll('.form-fields-container')
             .data([0]);

modules/ui/preset_editor.js

@@ -117,6 +117,7 @@ export function uiPresetEditor(context) {
     presetEditor.tags = function(val) {
         if (!arguments.length) return _tags;
         _tags = val;
+        formFields.tagsChanged();
         // Don't reset _fieldsArr here.
         return presetEditor;
     };