Merge pull request #2281 from mccarthysean/fix-inline-model-AJAX-look…

…up-to-use-new_name

reset the pre-configured loader's name to the "new_name"

examples/sqla-custom-inline-forms/app.py

@@ -1,5 +1,6 @@
 import os
 import os.path as op
+from pathlib import Path
 
 from werkzeug.utils import secure_filename
 from sqlalchemy import event
@@ -10,6 +11,7 @@
 from wtforms import fields
 
 import flask_admin as admin
+from flask_admin.contrib.sqla.ajax import QueryAjaxModelLoader
 from flask_admin.form import RenderTemplateWidget
 from flask_admin.model.form import InlineFormAdmin
 from flask_admin.contrib.sqla import ModelView
@@ -37,6 +39,22 @@ class Location(db.Model):
     name = db.Column(db.Unicode(64))
 
 
+class ImageType(db.Model):
+    """
+    Just so the LocationImage can have another foreign key,
+    so we can test the "form_ajax_refs" inside the "inline_models"
+    """
+    id = db.Column(db.Integer, primary_key=True)
+    name = db.Column(db.String(64))
+
+    def __repr__(self) -> str:
+        """
+        Represent this model as a string
+        (e.g. in the Image Type list dropdown when creating an inline model)
+        """
+        return self.name
+
+
 class LocationImage(db.Model):
     id = db.Column(db.Integer, primary_key=True)
     alt = db.Column(db.Unicode(128))
@@ -45,6 +63,9 @@ class LocationImage(db.Model):
     location_id = db.Column(db.Integer, db.ForeignKey(Location.id))
     location = db.relation(Location, backref='images')
 
+    image_type_id = db.Column(db.Integer, db.ForeignKey(ImageType.id))
+    image_type = db.relation(ImageType, backref='images')
+
 
 # Register after_delete handler which will delete image file after model gets deleted
 @event.listens_for(LocationImage, 'after_delete')
@@ -76,13 +97,26 @@ class CustomInlineModelConverter(InlineModelConverter):
 
 
 # Customized inline form handler
-class InlineModelForm(InlineFormAdmin):
+class LocationImageInlineModelForm(InlineFormAdmin):
     form_excluded_columns = ('path',)
 
     form_label = 'Image'
 
+    # Setup AJAX lazy-loading for the ImageType inside the inline model
+    form_ajax_refs = {
+        "image_type": QueryAjaxModelLoader(
+            name="image_type",
+            session=db.session,
+            model=ImageType,
+            fields=("name",),
+            order_by="name",
+            placeholder="Please use an AJAX query to select an image type for the image",
+            minimum_input_length=0,
+        )
+    }
+
     def __init__(self):
-        return super(InlineModelForm, self).__init__(LocationImage)
+        return super(LocationImageInlineModelForm, self).__init__(LocationImage)
 
     def postprocess_form(self, form_class):
         form_class.upload = fields.FileField('Image')
@@ -100,7 +134,7 @@ def on_model_change(self, form, model):
 class LocationAdmin(ModelView):
     inline_model_form_converter = CustomInlineModelConverter
 
-    inline_models = (InlineModelForm(),)
+    inline_models = (LocationImageInlineModelForm(),)
 
     def __init__(self):
         super(LocationAdmin, self).__init__(Location, db.session, name='Locations')
@@ -113,21 +147,38 @@ def index():
     return render_template('locations.html', locations=locations)
 
 
-if __name__ == '__main__':
-    # Create upload directory
-    try:
-        os.mkdir(base_path)
-    except OSError:
-        pass
+def first_time_setup():
+    """Run this to setup the database for the first time"""
+    # Create DB
+    db.drop_all()
+    db.create_all()
+
+    # Add some image types for the form_ajax_refs inside the inline_model
+    image_types = ("JPEG", "PNG", "GIF")
+    for image_type in image_types:
+        model = ImageType(name=image_type)
+        db.session.add(model)
+
+    db.session.commit()
+
+    return
+
+
+# if __name__ == '__main__':
+# Create upload directory
+try:
+    os.mkdir(base_path)
+except OSError:
+    pass
 
     # Create admin
     admin = admin.Admin(app, name='Example: Inline Models')
 
     # Add views
     admin.add_view(LocationAdmin())
 
-    # Create DB
-    db.create_all()
+# Create DB
+first_time_setup()
 
     # Start app
     app.run(debug=True)

flask_admin/contrib/sqla/form.py

@@ -636,6 +636,12 @@ def process_ajax_refs(self, info):
                     loader = create_ajax_loader(info.model, self.session, new_name, name, opts)
                 else:
                     loader = opts
+                    # If we're changing the name in self.view._form_ajax_refs,
+                    # we must also change loader.name property. Otherwise
+                    # when the widget tries to set the 'data-url' property in the <input> tag,
+                    # it won't be able to find the loader since it'll be using the "field.loader.name"
+                    # of the previously-configured loader.
+                    setattr(loader, "name", new_name)
 
                 result[name] = loader
                 self.view._form_ajax_refs[new_name] = loader