collective.mcp 0.5

Creating categories

The first step is to create the categories to which the pages will belong. If you have a look at the screenshots in the docs folder or on the project wiki, there is four categories:

• personal preferences

• clients

• templates

• settings

In our example, we’ll only create the first and last categories. To do so, in the __init__.py, we’ll add the following code:

>>> register_category(
...     Category('personal',
...              _(u'label_cpcat_personal_prefs',
...                default=u'Personal preferences')))
>>> register_category(
...     Category('settings',
...              _(u'label_cpcat_settings',
...                default=u'Settings'),
...              after='personal'))

As you can see, we specified that the ‘settings’ category will appear after the ‘personal’ one. We could also have specified that ‘personal’ is before ‘settings’ and get the same result.

If you reload now the control panel, nothing has changed. That is normal, the system does not display categories for which there is no page (or the user can not use any of the pages).

>>> categories
[Category: personal, Category: settings]
>>> pages
[]

Creating a simple page

collective.mcp is based on collective.multimodeview. For the pages, we will rely on a view defined in the samples called ‘multimodeview_notes_sample’. If you have already activated the samples for multimodeview, you do not have to do anything. In the other case, add the following lines to your configure.zcml file:

<browser:page
    for="*"
    name="multimodeview_notes_sample"
    class="collective.multimodeview.samples.notes_view.NotesView"
    permission="zope2.View"
    />

The first page we will create allows to update the ‘home message’, using the API provded by the view declared above. The API is pretty simple and do not realy need explanations:

• get_home_message()

• set_home_message(msg)

This message is not displayed anywhere. It could, but that’s not covered by this README.

To create our page, we’ll first create a new python file in the control panel package, called ‘home_message.py’, that contains the following code:

from collective.mcp.browser.control_panel_page import ControlPanelPage

class HomeMessage(ControlPanelPage):
    category = 'settings'
    zcml_id = 'collective_mcp_home_message'
    widget_id = 'collective_mcp_home_message'

    modes = {'back': {},
             'default': {'submit_label': 'Update home message',
                         'success_msg': 'The home message has been updated'}}

    default_mode = 'default'

    @property
    def notes_view(self):
        return self.context.restrictedTraverse('@@multimodeview_notes_sample')

    def _check_default_form(self):
        return True

    def _process_default_form(self):
        self.notes_view.set_home_message(
            self.request.form.get('msg', ''))
        return 'back'

Let’s have a look to what we defined:

- 'category': this is the category to which our now page belongs

- 'zmcl_id': this is the name of the page, as defined in the zcml
  file (we'll see it later)

- 'widget_id': this is a unique identifier for your page. Here we
  used the same one that for the zcml_id ust to avoid any conflict,
  but it could have benn 'home_message' for example.

- modes: this dictionnary defines the list of modes in which the page
  can be. We defined a 'back' mode, that means that when the form is
  submitted or when the user cancels, the home of the conrol panel
  will be shown instead of the form again. For the default mode, we
  also defined the name of the button to save and the message
  displayed on success. Have a look to collective.multimodeview
  README file to see more options you can define for modes.

- notes_view: just a helper property to easily get the view with the
  API.

- _check_default_form: a function that checks that the form submitted
  did not contain error. Here we do not check anything so it's prettu
  quick, the second example will show more. see
  colective.multimodeview for more explanation).

- _process_default_form: the function called if no errors were found
  by the previous method. As you can guess by the name, it processes
  the form (here it updates the home message).

Now we need a template for our view:

<form method="post"
      tal:attributes="action view/get_form_action">

  <div class="field">
    <label for="msg">Message:</label>
    <input type="text"
           name="msg"
           tal:attributes="value view/notes_view/get_home_message" />
  </div>
  <span tal:replace="structure view/make_form_extras" />
</form>

There is nothing fancy here, except the use of two methods from multimodeview:

- view/get_form_action: gives the action for the form

- view/make_form_extra: generates some HTML code with some hidden
  input fields and the submit buttons.

Once again, have a look to collective.multimodeview for more explanations.

The last step is to declare our view in the zcml file and register it. First, in the __init__.py file:

>>> from collective.mcp.samples.home_message import HomeMessage
>>> register_page(HomeMessage)

This makes the page appear in the pages list:

>>> pages
[<class 'collective.mcp.samples.home_message.HomeMessage'>]

Then in the ZCML file:

<browser:page
    for="*"
    name="collective_mcp_home_message"
    class=".HomeMessage"
    permission="zope.Public"
    template="home_message.pt"
    />

Now you can restart the server and reload the control panel. The ‘settings’ category will appear, containing one page with a question mark icon.

>>> self.browser.open('http://nohost/plone/control_panel/')
>>> 'There is nothing you can manage.' in self.browser.contents
False

>>> '<span class="spacer">Settings</span>' in self.browser.contents
True

>>> '<span class="spacer">Personal preferences</span>' in self.browser.contents
False

First, let’s solve the icon problem. In the sample directory you will find two icons taken from this set: http://www.iconfinder.com/search/?q=iconset%3A49handdrawing

Let’s declare the home.png file in the zcml:

<browser:resource
    name="collective_mcp_home.png"
    file="home.png" />

And now in our view, we will use this icon:

class HomeMessage(ControlPanelPage):
    icon = "++resource++collective_mcp_home.png"

The second problem is that our page does not have a title, this problem can easily be solved too:

class HomeMessage(ControlPanelPage):
    title = 'Home message'

The image now appears in the control panel and the title is also displayed:

>>> '<img src="++resource++collective_mcp_home.png"' in self.browser.contents
True

>>> '<span>Home message</span>' in self.browser.contents
True

If we click on the icon, the main page is not displayed anymore and we see our form instead:

>>> self.browser.getLink('Home message').click()
>>> self.browser.url
'http://nohost/plone/control_panel?mode=default&widget_id=collective_mcp_home_message'

>>> '<img src="++resource++collective_mcp_home.png"' in self.browser.contents
False

>>> '<label for="msg">Message:</label>' in self.browser.contents
True

We can fill the home message and validate. We get a sucess message displayed and we are back on the control panel home page:

>>> self.browser.getControl(name='msg').value = 'My new home message - welcome :)'
>>> self.browser.getControl(name='form_submitted').click()
>>> "<dd>The home message has been updated</dd>" in self.browser.contents
True

If we had cancelled, we would have got a different message (which is the default cancel message inherited from collective.multimodeview)

>>> self.browser.getLink('Home message').click()
>>> self.browser.getControl(name='form_cancelled').click()
>>> "<dd>Changes have been cancelled.</dd>" in self.browser.contents
True

And that’s all, you have your first page of the control panel working. Ok it’s not really usefull, but that’s a good start. In Prettig personeel (www.prettigpersoneel.nl - the website for which this product has been developed), there is many pages based on the same principle (two modes: default and back) such as changing the password, setting the user’s theme, managing contact information etc.

But now we want to do something a bit harder: create a page to manage multiple objects.

Creating a multi-object managing page

If ou had a look at the ‘collective_multimodeview_notes_samples’ page, you see that its main goal it to manage a list of notes attached to the portal of the site. We will create a control panel page to manage those notes. To do so, creates notes.py and notes.pt in the control_panel package.

The notes.py will look like this:

from collective.mcp.browser.control_panel_page import ControlPanelPage

class Notes(ControlPanelPage):
    category = 'settings'
    zcml_id = 'collective_mcp_notes'
    widget_id = 'collective_mcp_notes'
    icon = "++resource++collective_mcp_notes.png"
    title = 'Notes'

    modes = {'add': {'success_msg': 'The note has been added',
                     'error_msg': 'Impossible to add a note: please correct the form',
                     'submit_label': 'Add note'},
             'edit': {'success_msg': 'The note has been edited',
                     'submit_label': 'Edit note'},
             'delete': {'success_msg': 'The note has been deleted',
                        'submit_label': 'Delete note'}
             }
    default_mode = 'edit'
    multi_objects = True

    @property
    def notes_view(self):
        return self.context.restrictedTraverse('@@multimodeview_notes_sample')

    def list_objects(self):
        notes = self.notes_view.get_notes()

        return [{'id': note_id, 'title': note_text}
                for note_id, note_text in enumerate(notes)
                if note_text]

    def _get_note_id(self):
        notes = self.notes_view.get_notes()
        note_id = self.current_object_id()

        try:
            note_id = int(note_id)
        except:
            # This should not happen, something wrong happened
            # with the form.
            return

        if note_id < 0 or note_id >= len(notes):
            # Again, something wrong hapenned.
            return

        if notes[note_id] is None:
            # This note has been deleted, nothing should be done
            # with it.
            return

        return note_id

    def get_note_title(self):
        """ Returns the title of the note currently edited.
        """
        if self.errors:
            return self.request.form.get('title')

        if self.is_add_mode:
            return ''

        note_id = self._get_note_id()
        if note_id is None:
            # This should not happen.
            return ''

        return self.notes_view.get_notes()[note_id]

    def _check_add_form(self):
        if not self.request.form.get('title'):
            self.errors['title'] = 'You must provide a title'

        return True

    def _check_edit_form(self):
        if self._get_note_id() is None:
            return

        return self._check_add_form()

    def _check_delete_form(self):
        return self._get_note_id() is not None

    def _process_add_form(self):
        self.notes_view.add_note(self.request.form.get('title'))
        self.request.form['obj_id'] = len(self.notes_view.get_notes()) - 1

    def _process_edit_form(self):
        self.notes_view.edit_note(
            self._get_note_id(),
            self.request.form.get('title'))

    def _process_delete_form(self):
        self.notes_view.delete_note(self._get_note_id())
        self.request.form['obj_id'] = None

So let’s see what is different from the previous page (obviously a lot):

• modes: there is no more ‘back’ mode, so when submitting the form, we will still see the same page. Some extra modes appears to manage the notes.

• default_mode: it is set to ‘edit’. It means that the page will try, by default, to edit the first object found.

• multi_objects: is is set to True. That means that this page can be used to manage multiple object. A sidebar will be shown to display the list of objects.

• list_objects: when setting ‘multi_objects’ to True, you have to define this method. It returns a list of dictionnary having two keys: one define the id of the object and the second one the title displayed.

The _check_xxx_form amd _process_xxx_form are quite similar to what we saw previously. One point to look at is the fact that we modify the ‘obj_id’ entry of the request in both _process_add_form and _process_delete_form. In the first case, we do that so the note that has just been added with be considered as the current one. In the second case, we delete the entry so the system will not consider the deleted note as the current one (as it does not exist anymore) and will pick the first available one.

Now let’s create a template for our page:

<tal:block tal:define="notes view/notes_view/get_notes;
                       note_exists python: bool([n for n in notes if n])">
  <form method="post"
        tal:condition="python: note_exists or view.is_add_mode"
        tal:define="note_title view/get_note_title"
        tal:attributes="action view/get_form_action">

    <tal:block tal:condition="python: view.is_add_mode or view.is_edit_mode">
      <div tal:attributes="class python: view.class_for_field('title')">
        <label for="title">Title</label>
        <div class="error_msg"
             tal:condition="view/errors/title|nothing"
             tal:content="view/errors/title" />
        <input type="text"
               name="title"
               tal:attributes="value note_title" />
      </div>
    </tal:block>

    <tal:block tal:condition="view/is_delete_mode">
      <p>Are you sure you want to delete this note ?</p>

      <p class="discreet"
         tal:content="note_title" />
    </tal:block>

    <input type="hidden"
           name="obj_id"
           tal:define="obj_id view/current_object_id"
           tal:condition="obj_id"
           tal:attributes="value obj_id" />

    <span tal:replace="structure view/make_form_extras" />
  </form>

  <p tal:condition="not: python: note_exists or view.is_add_mode">
    There is no note to manage, click the '+' button to create a new one.
  </p>
</tal:block>

In this template, we can see three important things:

• the use of view/is_xxx_mode: this is a helper provided by collective.multimodeview to now what o display depending on what you are doing.

• there is an hidden field called ‘obj_id’. This is important, as it is used to know which object you are currently editing.

• there is a default message displayed when there is no notes. Do not forget it. If your page rendered an empty string, the system will show the home page of the menu instead.

Now let’s register our page. First in the __init__.py file:

>>> from collective.mcp.samples.notes import Notes
>>> register_page(Notes)

>>> pages
[<class 'collective.mcp.samples.home_message.HomeMessage'>,
 <class 'collective.mcp.samples.notes.Notes'>]

and in the configure.zcml:

<browser:page
    for="*"
    name="collective_mcp_notes"
    class=".Notes"
    permission="zope.Public"
    template="notes.pt"
    />

Restart your server and reload the control panel, you now have two pages available.

>>> self.browser.open('http://nohost/plone/control_panel/')
>>> self.browser.getLink('Notes').click()
>>> self.browser.url
'http://nohost/plone/control_panel?mode=edit&widget_id=collective_mcp_notes'

As you have not played with the notes yet, the list on the right is empty and you get a message telling you to add some notes:

>>> import re
>>> re.search('(<ul class="objects">\s*</ul>)', self.browser.contents).groups()
('<ul class="objects">...</ul>',)

>>> "There is no note to manage, click the '+' button to create a new one." in self.browser.contents
True

collective.mcp automatically added a ‘+’ and a ‘-’ button that will trigger the add and delete modes of your new page. We’ll click on the add button that will display the form to create a note:

>>> self.browser.getLink('+').click()
>>> self.browser.url
'http://nohost/plone/control_panel?mode=add&widget_id=collective_mcp_notes'

>>> '<label for="title">Title</label>' in self.browser.contents
True

You can also notice that, when adding a new object, a new line appears in the objects list and is shown as selected:

>>> re.search('(<li\s*class="current">\s*<a>...</a>\s*</li>)', self.browser.contents).groups()
('<li class="current">...<a>...</a>...</li>',)

Now we’ll add a note objects:

>>> self.browser.getControl(name='title').value = 'A new note'
>>> self.browser.getControl(name='form_submitted').click()

This time we are not redirected to the control panel home page but to the edit page of the object we just added and we get a success message:

>>> '<dd>The note has been added</dd>' in self.browser.contents
True

>>> re.search('(<li class="current">\s*<a href=".*">A new note</a>\s*</li>)', self.browser.contents).groups()
('<li class="current">...<a href="...">A new note</a>...</li>',)

>>> re.search('(<input type="text" name="title"\s*value="A new note" />)', self.browser.contents).groups()
('<input type="text" name="title" value="A new note" />',)

We now add a second note:

>>> self.browser.getLink('+').click()
>>> self.browser.getControl(name='title').value = 'My second note'
>>> self.browser.getControl(name='form_submitted').click()

When saving this note is selected by default:

>>> re.search('(<li class="current">\s*<a href=".*">My second note</a>\s*</li>)', self.browser.contents).groups()
('<li class="current">...<a href="...">My second note</a>...</li>',)

>>> re.search('(<input type="text" name="title"\s*value="My second note" />)', self.browser.contents).groups()
('<input type="text" name="title"...value="My second note" />',)

More documentation

You will find more documentation in collective/mcp/doc. There is four extra documentations there:

- modes.rst - some extra explanation about the ``modes`` attributes
  of the class.

- restriction.rst - explains the diferent methods to restrict access
  to the pages.

- multiobjects.rst - going a bit deeper with the multi-objects views.

- defect.rst - some examples of what you should not do.

- theming.rst - some hints for theming the control panel.

0.5 (2015-08-27)

• Code cleanup. [maurits]

0.4 (2013-09-24)

• Moved to github. Cleanup a bit. [maurits]

0.3 (2012-10-30)

• better display of the buttons in the left panel. [vincent]

0.2 (2011-12-15)

• Added possibility to set custom CSS class to the subpage. By default, it has the class ‘mcp_widget_XXX’ where XXX is the widget id. [vincent]

0.1 (2011-02-25)

• Initial release. [vincent]