[Peterborough] Disable pin snapping for new tree requests

We don't want to plant trees where there are already trees, so we add a
separate layer for new tree requests, and disable pin snapping for that
layer.

This adds a new option for layers named "relevant". If provided it will
be called with an options object, allowing you to check ".category" and
".group" and return a boolean for whether you want to display the layer
based on the passed options.

Note: You still need to provide an "asset_group" option even if you use
the "relevant" option as this is used elsewhere.

The "regular" tree-points layer uses this to exclude just the new trees
subcategory from being displayed.

2 files changed, 26 insertions, 2 deletions

diff --git a/web/cobrands/fixmystreet/assets.js b/web/cobrands/fixmystreet/assets.js
index ac22b6dde..0a08c0f69 100644
--- a/web/cobrands/fixmystreet/assets.js
+++ b/web/cobrands/fixmystreet/assets.js
@@ -31,7 +31,9 @@ OpenLayers.Layer.VectorAsset = OpenLayers.Class(OpenLayers.Layer.Vector, {
           group = $('select#category_group').val(),
           layer = this.fixmystreet,
           relevant;
-      if (layer.asset_group) {
+      if (layer.relevant) {
+          relevant = layer.relevant({category: category, group: group});
+      } else if (layer.asset_group) {
           relevant = (layer.asset_group === group);
       } else {
           relevant = (OpenLayers.Util.indexOf(layer.asset_category, category) != -1);
diff --git a/web/cobrands/peterborough/assets.js b/web/cobrands/peterborough/assets.js
index 7bc1df574..6f5896d72 100644
--- a/web/cobrands/peterborough/assets.js
+++ b/web/cobrands/peterborough/assets.js
@@ -53,6 +53,8 @@ fixmystreet.assets.add(defaults, {
     asset_item: 'tree group'
 });
 
+var NEW_TREE_CATEGORY_NAME = 'Request for tree to be planted';
+
 fixmystreet.assets.add(defaults, {
     http_options: {
         url: "https://tilma.staging.mysociety.org/mapserver/peterborough",
@@ -66,7 +68,27 @@ fixmystreet.assets.add(defaults, {
     },
     asset_type: 'spot',
     asset_group: 'Trees',
-    asset_item: 'tree'
+    asset_item: 'tree',
+    relevant: function(options) {
+        return options.group === 'Trees' && options.category !== NEW_TREE_CATEGORY_NAME;
+    }
+});
+
+// We don't want to plant trees where the existing trees are, so add a
+// separate layer with pin-snapping disabled for new tree requests.
+// The new tree request category is disabled in the other tree point layer.
+fixmystreet.assets.add(defaults, {
+    http_options: {
+        url: "https://tilma.staging.mysociety.org/mapserver/peterborough",
+        params: {
+            TYPENAME: "tree_points"
+        }
+    },
+    asset_id_field: 'TREE_CODE',
+    asset_type: 'spot',
+    asset_category: NEW_TREE_CATEGORY_NAME,
+    asset_item: 'tree',
+    disable_pin_snapping: true
 });
 
 })();