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1 HTML form construction |
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2 ---------------------- |
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3 |
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4 CubicWeb provides the somewhat usual form / field / widget / renderer abstraction |
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5 to provide generic building blocks which will greatly help you in building forms |
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6 properly integrated with CubicWeb (coherent display, error handling, etc...), |
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7 while keeping things as flexible as possible. |
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8 |
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9 A ``form`` basically only holds a set of ``fields``, and has te be bound to a |
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10 ``renderer`` which is responsible to layout them. Each field is bound to a |
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11 ``widget`` that will be used to fill in value(s) for that field (at form |
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12 generation time) and 'decode' (fetch and give a proper Python type to) values |
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13 sent back by the browser. |
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14 |
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15 The ``field`` should be used according to the type of what you want to edit. |
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16 E.g. if you want to edit some date, you'll have to use the |
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17 :class:`cubicweb.web.formfields.DateField`. Then you can choose among multiple |
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18 widgets to edit it, for instance :class:`cubicweb.web.formwidgets.TextInput` (a |
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19 bare text field), :class:`~cubicweb.web.formwidgets.DateTimePicker` (a simple |
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20 calendar) or even :class:`~cubicweb.web.formwidgets.JQueryDatePicker` (the JQuery |
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21 calendar). You can of course also write your own widget. |
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22 |
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23 |
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24 .. automodule:: cubicweb.web.views.autoform |
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25 |
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26 |
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27 Example of ad-hoc fields form |
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28 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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29 |
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30 We want to define a form doing something else than editing an entity. The idea is |
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31 to propose a form to send an email to entities in a resultset which implements |
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32 :class:`IEmailable`. Let's take a simplified version of what you'll find in |
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33 :mod:`cubicweb.web.views.massmailing`. |
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34 |
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35 Here is the source code: |
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36 |
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37 .. sourcecode:: python |
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38 |
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39 def sender_value(form): |
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40 return '%s <%s>' % (form._cw.user.dc_title(), form._cw.user.get_email()) |
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41 |
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42 def recipient_choices(form, field): |
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43 return [(e.get_email(), e.eid) |
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44 for e in form.cw_rset.entities() |
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45 if e.get_email()] |
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46 |
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47 def recipient_value(form): |
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48 return [e.eid for e in form.cw_rset.entities() |
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49 if e.get_email()] |
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50 |
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51 class MassMailingForm(forms.FieldsForm): |
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52 __regid__ = 'massmailing' |
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53 |
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54 needs_js = ('cubicweb.widgets.js',) |
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55 domid = 'sendmail' |
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56 action = 'sendmail' |
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57 |
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58 sender = ff.StringField(widget=TextInput({'disabled': 'disabled'}), |
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59 label=_('From:'), |
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60 value=sender_value) |
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61 |
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62 recipient = ff.StringField(widget=CheckBox(), |
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63 label=_('Recipients:'), |
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64 choices=recipient_choices, |
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65 value=recipients_value) |
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66 |
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67 subject = ff.StringField(label=_('Subject:'), max_length=256) |
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68 |
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69 mailbody = ff.StringField(widget=AjaxWidget(wdgtype='TemplateTextField', |
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70 inputid='mailbody')) |
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71 |
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72 form_buttons = [ImgButton('sendbutton', "javascript: $('#sendmail').submit()", |
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73 _('send email'), 'SEND_EMAIL_ICON'), |
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74 ImgButton('cancelbutton', "javascript: history.back()", |
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75 stdmsgs.BUTTON_CANCEL, 'CANCEL_EMAIL_ICON')] |
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76 |
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77 Let's detail what's going on up there. Our form will hold four fields: |
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78 |
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79 * a sender field, which is disabled and will simply contains the user's name and |
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80 email |
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81 |
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82 * a recipients field, which will be displayed as a list of users in the context |
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83 result set with checkboxes so user can still choose who will receive his mailing |
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84 by checking or not the checkboxes. By default all of them will be checked since |
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85 field's value return a list containing same eids as those returned by the |
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86 vocabulary function. |
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87 |
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88 * a subject field, limited to 256 characters (hence we know a |
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89 :class:`~cubicweb.web.formwidgets.TextInput` will be used, as explained in |
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90 :class:`~cubicweb.web.formfields.StringField`) |
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91 |
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92 * a mailbody field. This field use an ajax widget, defined in `cubicweb.widgets.js`, |
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93 and whose definition won't be shown here. Notice though that we tell this form |
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94 need this javascript file by using `needs_js` |
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95 |
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96 Last but not least, we add two buttons control: one to post the form using |
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97 javascript (`$('#sendmail')` being the jQuery call to get the element with DOM id |
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98 set to 'sendmail', which is our form DOM id as specified by its `domid` |
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99 attribute), another to cancel the form which will go back to the previous page |
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100 using another javascript call. Also we specify an image to use as button icon as a |
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101 resource identifier (see :ref:`external_resources`) given as last argument to |
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102 :class:`cubicweb.web.formwidgets.ImgButton`. |
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103 |
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104 To see this form, we still have to wrap it in a view. This is pretty simple: |
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105 |
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106 .. sourcecode:: python |
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107 |
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108 class MassMailingFormView(form.FormViewMixIn, EntityView): |
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109 __regid__ = 'massmailing' |
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110 __select__ = implements(IEmailable) & authenticated_user() |
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111 |
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112 def call(self): |
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113 form = self._cw.vreg['forms'].select('massmailing', self._cw, |
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114 rset=self.cw_rset) |
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115 self.w(form.render()) |
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116 |
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117 As you see, we simply define a view with proper selector so it only apply to a |
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118 result set containing :class:`IEmailable` entities, and so that only users in the |
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119 managers or users group can use it. Then in the `call()` method for this view we |
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120 simply select the above form and write what its `.render()` method returns. |
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121 |
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122 When this form is submitted, a controller with id 'sendmail' will be called (as |
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123 specified using `action`). This controller will be responsible to actually send |
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124 the mail to specified recipients. |
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125 |
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126 Here is what it looks like: |
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127 |
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128 .. sourcecode:: python |
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129 |
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130 class SendMailController(Controller): |
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131 __regid__ = 'sendmail' |
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132 __select__ = (authenticated_user() & |
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133 match_form_params('recipient', 'mailbody', 'subject')) |
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134 |
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135 def publish(self, rset=None): |
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136 body = self._cw.form['mailbody'] |
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137 subject = self._cw.form['subject'] |
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138 eids = self._cw.form['recipient'] |
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139 # eids may be a string if only one recipient was specified |
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140 if isinstance(eids, basestring): |
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141 rset = self._cw.execute('Any X WHERE X eid %(x)s', {'x': eids}) |
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142 else: |
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143 rset = self._cw.execute('Any X WHERE X eid in (%s)' % (','.join(eids))) |
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144 recipients = list(rset.entities()) |
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145 msg = format_mail({'email' : self._cw.user.get_email(), |
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146 'name' : self._cw.user.dc_title()}, |
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147 recipients, body, subject) |
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148 if not self._cw.vreg.config.sendmails([(msg, recipients]): |
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149 msg = self._cw._('could not connect to the SMTP server') |
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150 else: |
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151 msg = self._cw._('emails successfully sent') |
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152 raise Redirect(self._cw.build_url(__message=msg)) |
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153 |
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154 |
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155 The entry point of a controller is the publish method. In that case we simply get |
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156 back post values in request's `form` attribute, get user instances according |
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157 to eids found in the 'recipient' form value, and send email after calling |
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158 :func:`format_mail` to get a proper email message. If we can't send email or |
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159 if we successfully sent email, we redirect to the index page with proper message |
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160 to inform the user. |
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161 |
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162 Also notice that our controller has a selector that deny access to it |
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163 to anonymous users (we don't want our instance to be used as a spam |
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164 relay), but also checks if the expected parameters are specified in |
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165 forms. That avoids later defensive programming (though it's not enough |
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166 to handle all possible error cases). |
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167 |
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168 To conclude our example, suppose we wish a different form layout and that existent |
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169 renderers are not satisfying (we would check that first of course :). We would then |
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170 have to define our own renderer: |
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171 |
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172 .. sourcecode:: python |
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173 |
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174 class MassMailingFormRenderer(formrenderers.FormRenderer): |
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175 __regid__ = 'massmailing' |
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176 |
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177 def _render_fields(self, fields, w, form): |
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178 w(u'<table class="headersform">') |
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179 for field in fields: |
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180 if field.name == 'mailbody': |
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181 w(u'</table>') |
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182 w(u'<div id="toolbar">') |
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183 w(u'<ul>') |
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184 for button in form.form_buttons: |
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185 w(u'<li>%s</li>' % button.render(form)) |
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186 w(u'</ul>') |
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187 w(u'</div>') |
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188 w(u'<div>') |
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189 w(field.render(form, self)) |
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190 w(u'</div>') |
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191 else: |
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192 w(u'<tr>') |
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193 w(u'<td class="hlabel">%s</td>' % self.render_label(form, field)) |
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194 w(u'<td class="hvalue">') |
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195 w(field.render(form, self)) |
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196 w(u'</td></tr>') |
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197 |
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198 def render_buttons(self, w, form): |
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199 pass |
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200 |
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201 We simply override the `_render_fields` and `render_buttons` method of the base form renderer |
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202 to arrange fields as we desire it: here we'll have first a two columns table with label and |
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203 value of the sender, recipients and subject field (form order respected), then form controls, |
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204 then a div containing the textarea for the email's content. |
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205 |
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206 To bind this renderer to our form, we should add to our form definition above: |
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207 |
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208 .. sourcecode:: python |
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209 |
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210 form_renderer_id = 'massmailing' |
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211 |
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212 API |
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213 ~~~ |
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214 |
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215 .. automodule:: cubicweb.web.formfields |
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216 .. automodule:: cubicweb.web.formwidgets |
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217 .. automodule:: cubicweb.web.views.forms |
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218 .. automodule:: cubicweb.web.views.formrenderers |
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219 |
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220 .. Example of entity fields form |