readme / filter values fix

Author: Lukas

README.md

@@ -0,0 +1,29 @@
+# django-admin-numeric-filter
+
+## Getting started
+
+1. Install package directly from GitHub
+
+```bash
+pip install git+https://[email protected]/lukasvinclav/django-admin-numeric-filter.git
+```
+
+2. Add **admin_numeric_filter** into **INSTALLED_APPS** in your setting file
+
+## Sample admin configuration
+
+```python
+from django.contrib import admin
+
+from admin_numeric_filter.admin import SingleNumericFilter, RangeNumericFilter, SliderNumericFilter
+
+from .models import YourModel
+
+@admin.register(YourModel)
+class YourModelAdmin(admin.ModelAdmin):
+    list_filter = (
+        ('field_A', SingleNumericFilter), # Single field search, **gte** lookup
+        ('field_B', RangeNumericFilter), # Range search, **gte** and **lte** lookup
+        ('field_C', SliderNumericFilter), # Same as range above but with slider
+    )
+```

admin_numeric_filter/admin.py

@@ -55,13 +55,15 @@ def __init__(self, field, request, params, model, model_admin, field_path):
 
     def queryset(self, request, queryset):
         filters = {}
-        
-        if self.used_parameters.get(self.parameter_name + '_from', None) is not None:
+
+        value_from = self.used_parameters.get(self.parameter_name + '_from', None)
+        if value_from is not None and value_from != '':
             filters.update({
                 self.parameter_name + '__gte': self.used_parameters.get(self.parameter_name + '_from', None),
             })
 
-        if self.used_parameters.get(self.parameter_name + '_to', None) is not None:
+        value_to = self.used_parameters.get(self.parameter_name + '_to', None)
+        if value_to is not None and value_to != '':
             filters.update({
                 self.parameter_name + '__lte': self.used_parameters.get(self.parameter_name + '_to', None),
             })