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1 .. -*- coding: utf-8 -*- |
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2 |
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3 Create your cube |
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4 ---------------- |
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5 |
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6 Once your `CubicWeb` development environment is set up, you can create a new |
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7 cube:: |
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8 |
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9 cubicweb-ctl newcube blog |
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10 |
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11 This will create in the cubes directory (``/path/to/forest/cubes`` for Mercurial |
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12 installation, ``/usr/share/cubicweb/cubes`` for debian packages installation) |
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13 a directory named ``blog`` reflecting the structure described in :ref:`cubesConcepts`. |
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14 |
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15 .. _DefineDataModel: |
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16 |
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17 Define your data model |
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18 ---------------------- |
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19 |
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20 The data model or schema is the core of your `CubicWeb` application. |
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21 It defines the type of content your application will handle. |
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22 |
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23 The data model of your cube ``blog`` is defined in the file ``schema.py``: |
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24 |
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25 :: |
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26 |
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27 class Blog(EntityType): |
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28 title = String(maxsize=50, required=True) |
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29 description = String() |
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30 |
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31 class BlogEntry(EntityType): |
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32 title = String(required=True, fulltextindexed=True, maxsize=256) |
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33 publish_date = Date(default='TODAY') |
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34 content = String(required=True, fulltextindexed=True) |
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35 entry_of = SubjectRelation('Blog', cardinality='?*') |
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36 |
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37 |
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38 A Blog has a title and a description. The title is a string that is |
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39 required by the class EntityType and must be less than 50 characters. |
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40 The description is a string that is not constrained. |
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41 |
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42 A BlogEntry has a title, a publish_date and a content. The title is a |
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43 string that is required and must be less than 100 characters. The |
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44 publish_date is a Date with a default value of TODAY, meaning that |
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45 when a BlogEntry is created, its publish_date will be the current day |
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46 unless it is modified. The content is a string that will be indexed in |
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47 the full-text index and has no constraint. |
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48 |
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49 A BlogEntry also has a relationship ``entry_of`` that links it to a |
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50 Blog. The cardinality ``?*`` means that a BlogEntry can be part of |
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51 zero or one Blog (``?`` means `zero or one`) and that a Blog can |
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52 have any number of BlogEntry (``*`` means `any number including |
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53 zero`). For completeness, remember that ``+`` means `one or more`. |
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54 |
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55 |
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56 Create your instance |
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57 -------------------- |
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58 |
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59 To use this cube as an application and create a new instance named ``blogdemo``, do:: |
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60 |
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61 cubicweb-ctl create blog blogdemo |
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62 |
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63 |
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64 This command will create the corresponding database and initialize it. |
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65 |
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66 Welcome to your web application |
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67 ------------------------------- |
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68 |
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69 Start your application in debug mode with the following command: :: |
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70 |
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71 cubicweb-ctl start -D blogdemo |
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72 |
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73 |
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74 You can now access your web application to create blogs and post messages |
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75 by visiting the URL http://localhost:8080/. |
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76 |
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77 A login form will appear. By default, the application will not allow anonymous |
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78 users to enter the application. To login, you need then use the admin account |
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79 you created at the time you initialized the database with ``cubicweb-ctl |
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80 create``. |
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81 |
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82 .. image:: ../../images/login-form.png |
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83 |
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84 |
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85 Once authenticated, you can start playing with your application |
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86 and create entities. |
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87 |
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88 .. image:: ../../images/blog-demo-first-page.png |
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89 |
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90 Please notice that so far, the `CubicWeb` franework managed all aspects of |
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91 the web application based on the schema provided at first. |
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92 |
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93 |
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94 Add entities |
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95 ------------ |
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96 |
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97 We will now add entities in our web application. |
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98 |
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99 Add a Blog |
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100 ~~~~~~~~~~ |
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101 |
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102 Let us create a few of these entities. Click on the `[+]` at the left of the |
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103 link Blog on the home page. Call this new Blog ``Tech-blog`` and type in |
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104 ``everything about technology`` as the description, then validate the form by |
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105 clicking on ``Validate``. |
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106 |
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107 .. image:: ../../images/cbw-create-blog.en.png |
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108 :alt: from to create blog |
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109 |
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110 Click on the logo at top left to get back to the home page, then |
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111 follow the Blog link that will list for you all the existing Blog. |
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112 You should be seeing a list with a single item ``Tech-blog`` you |
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113 just created. |
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114 |
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115 .. image:: ../../images/cbw-list-one-blog.en.png |
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116 :alt: displaying a list of a single blog |
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117 |
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118 Clicking on this item will get you to its detailed description except |
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119 that in this case, there is not much to display besides the name and |
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120 the phrase ``everything about technology``. |
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121 |
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122 Now get back to the home page by clicking on the top-left logo, then |
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123 create a new Blog called ``MyLife`` and get back to the home page |
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124 again to follow the Blog link for the second time. The list now |
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125 has two items. |
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126 |
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127 .. image:: ../../images/cbw-list-two-blog.en.png |
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128 :alt: displaying a list of two blogs |
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129 |
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130 Add a BlogEntry |
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131 ~~~~~~~~~~~~~~~ |
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132 |
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133 Get back to the home page and click on [+] at the left of the link |
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134 BlogEntry. Call this new entry ``Hello World`` and type in some text |
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135 before clicking on ``Validate``. You added a new blog entry without |
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136 saying to what blog it belongs. There is a box on the left entitled |
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137 ``actions``, click on the menu item ``modify``. You are back to the form |
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138 to edit the blog entry you just created, except that the form now has |
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139 another section with a combobox titled ``add relation``. Chose |
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140 ``entry_of`` in this menu and a second combobox appears where you pick |
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141 ``MyLife``. |
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142 |
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143 You could also have, at the time you started to fill the form for a |
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144 new entity BlogEntry, hit ``Apply`` instead of ``Validate`` and the |
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145 combobox titled ``add relation`` would have showed up. |
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146 |
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147 |
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148 .. image:: ../../images/cbw-add-relation-entryof.en.png |
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149 :alt: editing a blog entry to add a relation to a blog |
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150 |
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151 Validate the changes by clicking ``Validate``. The entity BlogEntry |
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152 that is displayed now includes a link to the entity Blog named |
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153 ``MyLife``. |
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154 |
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155 .. image:: ../../images/cbw-detail-one-blogentry.en.png |
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156 :alt: displaying the detailed view of a blogentry |
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157 |
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158 Note that all of this was handled by the framework and that the only input |
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159 that was provided so far is the schema. To get a graphical view of the schema, |
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160 point your browser to the URL http://localhost:8080/schema |
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161 |
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162 .. image:: ../../images/cbw-schema.en.png |
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163 :alt: graphical view of the schema (aka data-model) |
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164 |
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165 |
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166 .. _DefineViews: |
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167 |
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168 Define your entity views |
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169 ------------------------ |
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170 |
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171 Each entity defined in a model inherits default views allowing |
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172 different rendering of the data. You can redefine each of them |
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173 according to your needs and preferences. So let's see how the |
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174 views are defined. |
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175 |
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176 |
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177 The view selection principle |
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178 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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179 |
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180 A view is defined by a Python class which includes: |
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181 |
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182 - an identifier (all objects in `CubicWeb` are entered in a registry |
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183 and this identifier will be used as a key) |
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184 |
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185 - a filter to select the result sets it can be applied to |
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186 |
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187 A view has a set of methods complying |
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188 with the `View` class interface (`cubicweb.common.view`). |
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189 |
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190 `CubicWeb` provides a lot of standard views for the type `EntityView`; |
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191 for a complete list, read the code in directory ``cubicweb/web/views/``. |
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192 |
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193 A view is applied on a `result set` which contains a set of |
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194 entities we are trying to display. `CubicWeb` uses a selector |
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195 mechanism which computes for each available view a score: |
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196 the view with the highest score is then used to display the given `result set`. |
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197 The standard library of selectors is in |
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198 ``cubicweb.common.selector`` and a library of methods used to |
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199 compute scores is available in ``cubicweb.vregistry.vreq``. |
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200 |
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201 It is possible to define multiple views for the same identifier |
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202 and to associate selectors and filters to allow the application |
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203 to find the best way to render the data. |
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204 |
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205 For example, the view named ``primary`` is the one used to display |
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206 a single entity. We will now show you how to customize this view. |
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207 |
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208 |
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209 View customization |
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210 ~~~~~~~~~~~~~~~~~~ |
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211 |
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212 If you wish to modify the way a `BlogEntry` is rendered, you will have to |
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213 overwrite the `primary` view defined in the module ``views`` of the cube |
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214 ``cubes/blog/views.py``. |
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215 |
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216 We can for example add in front of the publication date a prefix specifying |
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217 that the date we see is the publication date. |
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218 |
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219 To do so, please apply the following changes: |
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220 |
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221 .. code-block:: python |
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222 |
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223 from cubicweb.web.views import baseviews |
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224 |
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225 |
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226 class BlogEntryPrimaryView(baseviews.PrimaryView): |
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227 |
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228 accepts = ('BlogEntry',) |
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229 |
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230 def render_entity_title(self, entity): |
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231 self.w(u'<h1>%s</h1>' % html_escape(entity.dc_title())) |
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232 |
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233 def content_format(self, entity): |
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234 return entity.view('reledit', rtype='content_format') |
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235 |
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236 def cell_call(self, row, col): |
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237 entity = self.entity(row, col) |
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238 |
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239 # display entity attributes with prefixes |
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240 self.w(u'<h1>%s</h1>' % entity.title) |
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241 self.w(u'<p>published on %s</p>' % entity.publish_date.strftime('%Y-%m-%d')) |
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242 self.w(u'<p>%s</p>' % entity.content) |
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243 |
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244 # display relations |
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245 siderelations = [] |
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246 if self.main_related_section: |
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247 self.render_entity_relations(entity, siderelations) |
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248 |
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249 .. note:: |
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250 When a view is modified, it is not required to restart the application |
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251 server. Save the Python file and reload the page in your web browser |
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252 to view the changes. |
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253 |
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254 You can now see that the publication date has a prefix. |
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255 |
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256 .. image:: ../../images/cbw-update-primary-view.en.png |
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257 :alt: modified primary view |
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258 |
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259 |
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260 The above source code defines a new primary view for ``BlogEntry``. |
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261 |
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262 Since views are applied to result sets and result sets can be tables of |
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263 data, we have to recover the entity from its (row,col)-coordinates. |
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264 The view has a ``self.w()`` method that is used to output data, in our |
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265 example HTML output. |
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266 |
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267 You can find more details about views and selectors in :ref:`ViewDefinition`. |
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268 |
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269 |