Source code for cubicweb.web.views.forms

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Base form classes

.. Note:

   Form is the glue that bind a context to a set of fields, and is rendered
   using a form renderer. No display is actually done here, though you'll find
   some attributes of form that are used to control the rendering process.

Besides the automagic form we'll see later, there are roughly two main
form classes in |cubicweb|:

.. autoclass:: cubicweb.web.views.forms.FieldsForm
.. autoclass:: cubicweb.web.views.forms.EntityFieldsForm

As you have probably guessed, choosing between them is easy. Simply ask you the
question 'I am editing an entity or not?'. If the answer is yes, use
:class:`EntityFieldsForm`, else use :class:`FieldsForm`.

Actually there exists a third form class:

.. autoclass:: cubicweb.web.views.forms.CompositeForm

but you'll use this one rarely.

import time
import inspect

from logilab.common import dictattr, tempattr
from logilab.common.decorators import iclassmethod, cached
from logilab.common.textutils import splitstrip

from cubicweb import ValidationError, neg_role
from cubicweb.predicates import non_final_entity, match_kwargs, one_line_rset
from cubicweb.web import RequestError, ProcessFormError
from cubicweb.web import form
from cubicweb.web.views import uicfg
from cubicweb.web.formfields import guess_field

[docs]class FieldsForm(form.Form): """This is the base class for fields based forms. **Attributes** The following attributes may be either set on subclasses or given on form selection to customize the generated form: :attr:`needs_js` sequence of javascript files that should be added to handle this form (through :meth:`~cubicweb.web.request.Request.add_js`) :attr:`needs_css` sequence of css files that should be added to handle this form (through :meth:`~cubicweb.web.request.Request.add_css`) :attr:`domid` value for the "id" attribute of the <form> tag :attr:`action` value for the "action" attribute of the <form> tag :attr:`onsubmit` value for the "onsubmit" attribute of the <form> tag :attr:`cssclass` value for the "class" attribute of the <form> tag :attr:`cssstyle` value for the "style" attribute of the <form> tag :attr:`cwtarget` value for the "target" attribute of the <form> tag :attr:`redirect_path` relative to redirect to after submitting the form :attr:`copy_nav_params` flag telling if navigation parameters should be copied back in hidden inputs :attr:`form_buttons` sequence of form control (:class:`~cubicweb.web.formwidgets.Button` widgets instances) :attr:`form_renderer_id` identifier of the form renderer to use to render the form :attr:`fieldsets_in_order` sequence of fieldset names , to control order :attr:`autocomplete` set to False to add 'autocomplete=off' in the form open tag **Generic methods** .. automethod:: cubicweb.web.form.Form.field_by_name(name, role=None) .. automethod:: cubicweb.web.form.Form.fields_by_name(name, role=None) **Form construction methods** .. automethod:: cubicweb.web.form.Form.remove_field(field) .. automethod:: cubicweb.web.form.Form.append_field(field) .. automethod:: cubicweb.web.form.Form.insert_field_before(field, name, role=None) .. automethod:: cubicweb.web.form.Form.insert_field_after(field, name, role=None) .. automethod:: cubicweb.web.form.Form.add_hidden(name, value=None, **kwargs) **Form rendering methods** .. automethod:: cubicweb.web.views.forms.FieldsForm.render **Form posting methods** Once a form is posted, you can retrieve the form on the controller side and use the following methods to ease processing. For "simple" forms, this should looks like : .. sourcecode :: python form = self._cw.vreg['forms'].select('myformid', self._cw) posted = form.process_posted() # do something with the returned dictionary Notice that form related to entity edition should usually use the `edit` controller which will handle all the logic for you. .. automethod:: cubicweb.web.views.forms.FieldsForm.process_posted .. automethod:: cubicweb.web.views.forms.FieldsForm.iter_modified_fields """ __regid__ = "base" # attributes overrideable by subclasses or through __init__ needs_js = ( "cubicweb.ajax.js", "cubicweb.edition.js", ) needs_css = ("cubicweb.form.css",) action = None cssclass = None cssstyle = None cwtarget = None redirect_path = None form_buttons = None form_renderer_id = "default" fieldsets_in_order = None autocomplete = True @property def needs_multipart(self): """true if the form needs enctype=multipart/form-data""" return any(field.needs_multipart for field in self.fields) def _get_onsubmit(self): try: return self._onsubmit except AttributeError: return "return freezeFormButtons('%(domid)s');" % dictattr(self) def _set_onsubmit(self, value): self._onsubmit = value onsubmit = property(_get_onsubmit, _set_onsubmit) def add_media(self): """adds media (CSS & JS) required by this widget""" if self.needs_js: self._cw.add_js(self.needs_js) if self.needs_css: self._cw.add_css(self.needs_css)
[docs] def render(self, formvalues=None, renderer=None, **kwargs): """Render this form, using the `renderer` given as argument or the default according to :attr:`form_renderer_id`. The rendered form is returned as a unicode string. `formvalues` is an optional dictionary containing values that will be considered as field's value. Extra keyword arguments will be given to renderer's :meth:`render` method. """ w = kwargs.pop("w", None) self.build_context(formvalues) if renderer is None: renderer = self.default_renderer() renderer.render(w, self, kwargs)
def default_renderer(self): return self._cw.vreg["formrenderers"].select( self.form_renderer_id, self._cw, rset=self.cw_rset, row=self.cw_row, col=self.cw_col or 0, ) formvalues = None def build_context(self, formvalues=None): """build form context values (the .context attribute which is a dictionary with field instance as key associated to a dictionary containing field 'name' (qualified), 'id', 'value' (for display, always a string). """ if self.formvalues is not None: return # already built self.formvalues = formvalues or {} # use a copy in case fields are modified while context is built (eg # __linkto handling for instance) for field in self.fields[:]: for field in field.actual_fields(self): field.form_init(self) # store used field in an hidden input for later usage by a controller fields = set() eidfields = set() for field in self.fields: if field.eidparam: eidfields.add(field.role_name()) elif not in self.control_fields: fields.add(field.role_name()) if fields: self.add_hidden("_cw_fields", ",".join(fields)) if eidfields: self.add_hidden("_cw_entity_fields", ",".join(eidfields), eidparam=True) _default_form_action_path = "edit" def form_action(self): action = self.action if action is None: return self._cw.build_url(self._default_form_action_path) return action # controller form processing methods #######################################
[docs] def iter_modified_fields(self, editedfields=None, entity=None): """return a generator on field that has been modified by the posted form. """ if editedfields is None: try: editedfields = self._cw.form["_cw_fields"] except KeyError: raise RequestError(self._cw._("no edited fields specified")) entityform = entity and len(inspect.getargspec(self.field_by_name)) == 4 # XXX for editedfield in splitstrip(editedfields): try: name, role = editedfield.split("-") except Exception: name = editedfield role = None if entityform: field = self.field_by_name(name, role, eschema=entity.e_schema) else: field = self.field_by_name(name, role) if field.has_been_modified(self): yield field
[docs] def process_posted(self): """use this method to process the content posted by a simple form. it will return a dictionary with field names as key and typed value as associated value. """ with tempattr(self, "formvalues", {}): # init fields value cache errors = [] processed = {} for field in self.iter_modified_fields(): try: for field, value in field.process_posted(self): processed[field.role_name()] = value except ProcessFormError as exc: errors.append((field, exc)) if errors: errors = {f.role_name(): str(ex) for f, ex in errors} raise ValidationError(None, errors) return processed
[docs]class EntityFieldsForm(FieldsForm): """This class is designed for forms used to edit some entities. It should handle for you all the underlying stuff necessary to properly work with the generic :class:`~cubicweb.web.views.editcontroller.EditController`. """ __regid__ = "base" __select__ = match_kwargs("entity") | (one_line_rset() & non_final_entity()) domid = "entityForm" uicfg_aff = uicfg.autoform_field uicfg_affk = uicfg.autoform_field_kwargs @iclassmethod def field_by_name(cls_or_self, name, role=None, eschema=None): """return field with the given name and role. If field is not explicitly defined for the form but `eclass` is specified, guess_field will be called. """ try: return super().field_by_name(name, role) except form.FieldNotFound: if eschema is None or role is None or name not in eschema.schema: raise rschema = eschema.schema.rschema(name) # XXX use a sample target type. Document this. tschemas = rschema.targets(eschema, role) fieldclass = cls_or_self.uicfg_aff.etype_get( eschema, rschema, role, tschemas[0] ) kwargs = cls_or_self.uicfg_affk.etype_get( eschema, rschema, role, tschemas[0] ) if kwargs is None: kwargs = {} if fieldclass: if not isinstance(fieldclass, type): return fieldclass # already an instance kwargs["fieldclass"] = fieldclass if isinstance(cls_or_self, type): req = None else: req = cls_or_self._cw field = guess_field( eschema, rschema, role, req=req, eidparam=True, **kwargs ) if field is None: raise return field def __init__(self, _cw, rset=None, row=None, col=None, **kwargs): try: self.edited_entity = kwargs.pop("entity") except KeyError: self.edited_entity = rset.complete_entity(row or 0, col or 0) msg = kwargs.pop("submitmsg", None) super().__init__(_cw, rset, row, col, **kwargs) self.uicfg_aff = self._cw.vreg["uicfg"].select( "autoform_field", self._cw, entity=self.edited_entity ) self.uicfg_affk = self._cw.vreg["uicfg"].select( "autoform_field_kwargs", self._cw, entity=self.edited_entity ) self.add_hidden("__type", self.edited_entity.cw_etype, eidparam=True) self.add_hidden("eid", self.edited_entity.eid) self.add_generation_time() # mainform default to true in parent, hence default to True if kwargs.get("mainform", True) or kwargs.get("mainentity", False): self.add_hidden("__maineid", self.edited_entity.eid) # If we need to directly attach the new object to another one if "__linkto" in self._cw.form: if msg: msg = "{} {}".format(msg, self._cw._("and linked")) else: msg = self._cw._("entity linked") if msg: msgid = self._cw.set_redirect_message(msg) self.add_hidden("_cwmsgid", msgid) def add_generation_time(self): # use %f to prevent (unlikely) display in exponential format self.add_hidden("__form_generation_time", "%.6f" % time.time(), eidparam=True) def add_linkto_hidden(self): """add the __linkto hidden field used to directly attach the new object to an existing other one when the relation between those two is not already present in the form. Warning: this method must be called only when all form fields are setup """ for (rtype, role), eids in self.linked_to.items(): # if the relation is already setup by a form field, do not add it # in a __linkto hidden to avoid setting it twice in the controller try: self.field_by_name(rtype, role) except form.FieldNotFound: for eid in eids: self.add_hidden("__linkto", f"{rtype}:{eid}:{role}") def render(self, *args, **kwargs): self.add_linkto_hidden() return super().render(*args, **kwargs) @property @cached def linked_to(self): linked_to = {} # case where this is an embeded creation form try: eid = int(self.cw_extra_kwargs["peid"]) except (KeyError, ValueError): # When parent is being created, its eid is not numeric (e.g. 'A') # hence ValueError. pass else: ltrtype = self.cw_extra_kwargs["rtype"] ltrole = neg_role(self.cw_extra_kwargs["role"]) linked_to[(ltrtype, ltrole)] = [eid] # now consider __linkto if the current form is the main form try: self.field_by_name("__maineid") except form.FieldNotFound: return linked_to for linkto in self._cw.list_form_param("__linkto"): ltrtype, eid, ltrole = linkto.split(":") linked_to.setdefault((ltrtype, ltrole), []).append(int(eid)) return linked_to def session_key(self): """return the key that may be used to store / retreive data about a previous post which failed because of a validation error """ if self.force_session_key is not None: return self.force_session_key # XXX if this is a json request, suppose we should redirect to the # entity primary view if self._cw.ajax_request and self.edited_entity.has_eid(): return f"{self.edited_entity.absolute_url()}#{self.domid}" # XXX we should not consider some url parameters that may lead to # different url after a validation error return f"{self._cw.url()}#{self.domid}" def default_renderer(self): return self._cw.vreg["formrenderers"].select( self.form_renderer_id, self._cw, rset=self.cw_rset, row=self.cw_row, col=self.cw_col, entity=self.edited_entity, ) def should_display_add_new_relation_link(self, rschema, existant, card): return False # controller side method (eg POST reception handling) def actual_eid(self, eid): # should be either an int (existant entity) or a variable (to be # created entity) assert eid or eid == 0, repr(eid) # 0 is a valid eid try: return int(eid) except ValueError: try: return["eidmap"][eid] except KeyError:["eidmap"][eid] = None return None def editable_relations(self): return ()
class CompositeFormMixIn: __regid__ = "composite" form_renderer_id = __regid__ def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) self.forms = [] def add_subform(self, subform): """mark given form as a subform and append it""" subform.parent_form = self self.forms.append(subform) def build_context(self, formvalues=None): super().build_context(formvalues) for form_ in self.forms: form_.build_context(formvalues)
[docs]class CompositeForm(CompositeFormMixIn, FieldsForm): """Form composed of sub-forms. Typical usage is edition of multiple entities at once. """
class CompositeEntityForm(CompositeFormMixIn, EntityFieldsForm): pass # XXX why is this class necessary?