I have a form in a web page and I need to fill it with many sql queries but only the first time the page is rendered. The other times, I want to fill it with the data from request.args. I decided to build a dictionnary that looks like the dictionnary of request.args to be able to use only one function to validate and fill my form. My function that fill my forms need to receive the dictionnary, the document(node that I need to change) and a signature (signature is a list of the name and the type of each elements from the form that need to be fill). In my template, I defined a wmfactory in the tag <form> that return my dictionnary. I’ve also define a wvfactory that call my function to fill the form. The problems is that wmfactory return a deferred so in wvfactory I have to call my function to fill like this: return model.getData(request).addCallback(my function). But I think that return doesn’t wait that the addCallback is done. Is there something I can do to make my returns wait for the addCallback to return the new node filled with the dictionnary of data. Here’s a part of my code: #verify is the function that fill and verify my form class handle: def __init__(self): pass def verify(self, dict, doc, signature): # dict is the dictionnary from the sql queries of the request.args # doc is the node <form> and it’s child error = 0 for item in signature: nodeList = domhelpers.locateNodes(doc, 'name', item[0]) #INTEGER, FLOAT and STRING if item[1] == 'integer' or item[1] == 'float' or item[1] == 'string': pass #CHECKBOX elif item[1] == 'checkbox': for node in nodeList: # dict est None s'il n'est pas cochee if dict.get(item[0]) != None and str(node.getAttribute('value')) in dict.get(item[0]): print 'checked' node.setAttribute('checked', 'checked') print node else: if item[2] == 'true': error = 1 l = microdom.lmx(node) l.span(style='color: red').text('donnees obligatoires') return doc # class that execute the queries needed class SummaryEditDB: def __init__(self, dbpool): self.dbpool = dbpool def getSummary(self, plan_id): sql = "select * from plan where plan_id = '%s'" %plan_id return self.dbpool.runQueryDict(sql) def getCategoriesIdByPlanId(self, plan_id): sql = """select to_plan_category_id from plan_categories where to_plan_id='%s' order by to_plan_category_id""" % plan_id return self.dbpool.runQueryDict(sql) class SummaryEditPage(pages.BasePage): templateFile = "summary_edit.html" def initialize(self, dbpool, *args): self.dbpool = dbpool self.db = SummaryEditDB(self.dbpool) self.signature = (('categories', 'checkbox', 'false', 'valeurs non correctes')) def executeSQL(self, plan_id): def createSummaryDict(results, newDict): for item in results[0]: for elem in self.signature: if item == elem[0]: newDict[item] = results[0][item] return self.db.getCategoriesIdByPlanId(plan_id).addCallback(createCategoriesDic t, newDict) def createCategoriesDict(results, newDict): newDict['categories'] = [] for item in results: newDict['categories'].append(str(item.get('to_plan_category_id'))) return newDict newDict = {} return self.db.getSummary(plan_id).addCallback(createSummaryDict, newDict) # first addCallback to fill the dictionnary def setUp(self, request, *args): self.planData = self.executeSQL(plan_id) #this call the function that return the dictionnary with the data (deferred) def wmfactory_planData(self, request): return self.planData # Usually, when I return an SQL queries, the model is not deferred but in this case, it is def wvfactory_fillFromSQL(self, request, node, model): def format(results): print results return handle().verify(results, node, self.signature) # the function that fill the form (replace attributes in the node) return self.planData.addCallback(format) # to be able to see the results of self.planData, I need to use a addCallback to be able to see the results and to call the form filler. But I seems that it doesn’t wait to the addCallback to be done def wchild_update(self, request): return self Here’s a part of my template file: <form action="/summary/edit/update" method="post" enctype="multipart/form-data" view="fillFromSQL" model="planData"> <table border="0" width="100%" cellspacing="1" cellpadding="2"> <tr> <td class="label" width="25%" valign="top">  Catégories </td> <td class="area" width="75%"> <input class="box" type="checkbox" name="categories" value="1000001" />1 étage<br /> <input class="box" type="checkbox" name="categories" value="1000002" />1/2 étages<br/> <input class="box" type="checkbox" name="categories" value="1000003" />2 étages<br/> <input class="box" type="checkbox" name="categories" value="1000004" />Split-Level<br /> <input class="box" type="checkbox" name="categories" value="1000005" />Chalet 4 saisons<br /> <input class="box" type="checkbox" name="categories" value="1000006" />Bi-Génération<br /> <input class="box" type="checkbox" name="categories" value="1000007" />Semi-Détaché<br /> <input class="box" type="checkbox" name="categories" value="1000008" />Townhouse<br /> <input class="box" type="checkbox" name="categories" value="1000009" />Duplex<br /> <input class="box" type="checkbox" name="categories" value="1000010" />Triplex<br /> <input class="box" type="checkbox" name="categories" value="1000011" />Appartement (4+)<br /> </td> </tr> </table> </form> I really need help, so if someone wants to help me, it will be appreciate. Thx in advance Vicky