Impreratively creating sequence of mapping schemas in Colander and Deform

Question

I am constructing a page where user can leave reviews for any number of products in Colander and Deform. I have grasped all the required elements, but I have still some issues of connecting the dots. Specifically, how I can imperatively (dynamically) create a sequence of N form items and then bind data for them?

This is my attempt for this far:

reviews =[
        {
            "product": "Shampoo",
            "comment": ""
            "rating": 3,
        },

        {
            "product": "Soap",
            "comment": "",
            "rating:" 3,
        },
    ]

rating = colander.Schema()
rating.add(colander.SchemaNode(colander.Int(), name="rating", missing=colander.null, validator=colander.Range(1, 5)))
rating.add(colander.SchemaNode(colander.String(), name="comment", validator=colander.Length(max=4096), missing=""))
ratings = colander.SequenceSchema(name="ratings", default=reviews, children=[rating])

# schema.add(colander.SchemaNode(colander.Sequence(), rating, name="ratings", default=reviews))
schema = CSRFSchema()
schema.add(ratings)

form = deform.Form(schema)
if request.method == "POST":
    controls = request.POST.items()

    try:
        captured = form.validate(controls)
    except deform.ValidationFailure as e:
        return {'form': e.render()}
else:
    rendered_form = form.render()

return locals()

But this results to error:

ValueError: Prototype for <deform.field.Field object at 4576735072 (schemanode 'ratings')> has no name

please fix code highlighting – Sascha Gottfried May 19 '15 at 06:28 — Sascha Gottfried, May 19 '15 at 06:28

score 1 · Accepted Answer · answered May 17 '15 at 23:27

Ok - figured it out. The innermost SchemaNode() must be named. One must use colander.SchemaNode(colander.Sequence()) to map out sequence of items.

reviews =[
        {
            "product": "Shampoo",
            "comment": "",
            "rating": 3,
        },

        {
            "product": "Soap",
            "comment": "",
            "rating": 3,
        },
    ]

rating = colander.Schema(name="single_rating")
rating.add(colander.SchemaNode(colander.Int(), name="rating", missing=colander.null, validator=colander.Range(1, 5)))
rating.add(colander.SchemaNode(colander.String(), name="comment", validator=colander.Length(max=4096), missing=""))
ratings = colander.SchemaNode(colander.Sequence(), rating, name="ratings", default=reviews)

# schema.add(colander.SchemaNode(colander.Sequence(), rating, name="ratings", default=reviews))
schema = CSRFSchema()
schema.add(ratings)

form = deform.Form(schema)
if request.method == "POST":
    controls = request.POST.items()

    try:
        captured = form.validate(controls)
    except deform.ValidationFailure as e:
        return {'form': e.render()}
else:
    rendered_form = form.render()

return locals()

Impreratively creating sequence of mapping schemas in Colander and Deform

1 Answers1