The "download" action does not return a dictionary, so it does not need a view. Wikis can be thought of as a mechanism to allow members of the group to create pages, but they can also be thought of as a way to develop applications in a modular way. The below screenshot shows the list of applications created in our web2py instance. This validator checks that a field value contains a valid date in the specified format. A form is not accepted if it has errors or when it has not been submitted (for example, the first time it is shown). If the Google App Engine SDK is installed the admin site page shows a button to push your applications to GAE. Use a minus (-) to prefix an un-ordered item and plus (+) to prefix an ordered item. We also require that the "image_id" be represented by the "title", '%(title)s', of the corresponding record. Go back to the edit page. If you click on edit, you can edit the file via a web interface. In order to use this feature, you must have the Mercurial version control libraries installed (at least version 1.9): The Mercurial web interface does allow you to browse previous commit and diff files but we do recommend you use Mercurial directly from the shell or one of the many GUI-based Mercurial clients since they are more powerful. You can create a new application simply by typing its name in the form on the top right of the site page in admin. Specifically we want to create: Go back to the edit page and edit the "default.py" controller, replacing its contents with the following: This action returns a dictionary. instructs web2py to use generic views (in our case "views/generic.rss") when the URL ends in the glob pattern ".rss". Note that you still have to call auth.wiki() in the controller or view in order to expose the wiki interface, since the resolve=False parameter instructs the auth object to just build the wiki model without any other interface setup. They are important for building custom forms and will be discussed later. The result of the select is a Rows object containing the records. Edit the controller and replace the "index" action with. The about tab allows editing the description of the application and its license. The simplest of the two is SQLFORM.grid. If a label is not provided, web2py derives the label from the field name (it capitalizes the field name and replaces underscores with spaces). Normally there is no need to perform any configuration of admin but a few customizations are possible. To set up web2py with mod_wsgi, create a new Apache configuration file: web2py knows how to upload files (via streaming if they are large), rename them safely, and store them. This widget works via Ajax. written by Massimo Di Pierro in English, 'http://www.google.com/search?q=define:name', # Note: no form instance is passed to the view, "/test/default/download/person.image.0246683463831.jpg", ## assuming db.define_table('person', Field('name')), #this prevents the submission from completing, #...or to add messages to specific elements on the form, "Do not name your child after prominent deities", web2py Portuguese (Translation in progress), The hidden field called "_formkey" is a one-time token that web2py uses to prevent double submission of forms. Notice that groupby, distinct, and left do not apply to Google App Engine. This can be done: record_changed works only with a SQLFORM and not with a FORM. The scaffolding app, sets default values of these parameters in the file "models/menu.py": In this section, we build a simple wiki from scratch using only low level APIs (as opposed to using the built-in wiki capabilities of web2py demonstrated in the next section). Line 6 defines a format string for the table. The items in the drop-down are stored as keys (db.image.id), but are represented by their db.image.title, as specified by the validator. Because you may want to enforce some authorization mechanism in the download function. It hides "blob" fields, since they are supposed to be handled differently, see More on uploads section in Chapter 6 for an example. The SQLFORM, upon deleting a record, does not delete the physical uploaded file(s) referenced by the record. The image below shows the output of the test page for the welcome application. This allows easy customization of the form using CSS and JavaScript. to get documentation. appadmin shows which databases are available and which tables exist in each database. We can now decorate the functions that we want to restrict, for example: will require login. Check for valid private network IPv6 address: This validator checks if a field's value is an IP address (either version 4 or version 6). It makes sure that you can only have numbers in "integer" and "double" fields, and that "time", "date" and "datetime" fields display the popup calendar/datepicker. Done! URLs are automatically converted into links. The form.accepted variable is set to True if the form was processed and passed validation. The name assigned by web2py to the uploaded file can be found in: There are cases when you want to generate forms as if you had a database table but you do not want the database table. Quick Reference It returns a validation failure if no data was uploaded. This table has a field called "title", a field called "file", and a field called "id" that serves as the table primary key ("id" is not explicitly declared because all tables have an id field by default). When set to True it only matches the whole string (from the beginning to the end): IS_MATCH takes an other optional argument search which defaults to False. It now indicates that "default.py exposes index". If you are a teacher and want to expose the administrative interface to students so that students can share one administrative interface for their projects (think of a virtual lab), can do it by setting: In this way students will be required to login and will only be able to access their own apps via admin. > The only requirement is to run it with gevent." The resulting hash takes the form alg$salt$hash, where alg is the hash algorithm used, salt is the salt string (which can be empty), and hash is the algorithm's output. The first argument is a table, not a query. We may want to pass different sets of parameters to these grids. For example, you may wish to add a checkbox which confirms the user agrees with the terms and conditions of your website: The variable my_extra_element should be adapted to the formstyle. We will put all these fields in a list. You, as first user/teacher, will be able to access them all. and to drop into the debugger, put this in the desired location: The debugger app has a breakpoint manager. licensed under, Complete Reference Manual, 6th Edition (pre-release). After you login into admin you can edit the admin configuration file via the URL: Notice that admin can be used to edit itself. Now consider the case of two tables linked by a reference field. Deprecated, an alias for IS_EMPTY_OR described below. When the above form object is serialized by {{=form}}, and because of the previous call to the accepts method, it now looks like this: Notice the presence of two hidden fields: "_formkey" and "_formname". Mind that the menu is appended to response.menu. Line 7 sets the value for the reference field, which is not part of the input form because of the, Line 8 creates an insert form SQLFORM for the, Line 9 processes the submitted form (the submitted form variables are in. To install applications on Heroku or other hosting system you should look into the "scripts" folder for the appropriate script. The requires argument is not a tag attribute (because it does not start by underscore) but it sets a validator for the value of visitor_name. Usually a form provides a single submit button. As an example, consider the following model: You can use the same controller action "display_form" shown above. To specify the URL to redirect to after a successful "create" record: To specify the URL to redirect to after a successful "update" record: To specify the URL to redirect to after a successful "delete" record: To specify the URL to be used for linking uploaded files: To specify extra functions to be executed after standard validation procedures for crud.create forms: StorageList is the same as a Storage object, they are both defined in the file "gluon/storage.py", but it defaults to [] as opposed to None. For example, consider the following model: You want to display the field coupon_code if and only if the have_coupon field is checked. Here is an example: When the visitor submits an empty form1, only form1 displays an error; if the visitor submits an empty form2, only form2 displays an error message. The visitor will be able to create pages, search them (by title), and edit them. sets the label of the "delete" checkbox in "update" forms. web2py also includes feedparser to read third-party feeds. One could create the extra links using a regular grid but they would point to a different action. It is important to follow the conventions described below. written by Massimo Di Pierro in English, """ this controller returns a dictionary rendered by the view, """browser, edit all documents attached to a certain page""", "ajax('callback', ['keyword'], 'target');", """an ajax callback that returns a

of links to wiki pages""", """generates rss feed from the wiki pages""", 'http://127.0.0.1:8000/mywiki/default/index', """finds pages that contain keyword for XML-RPC""", """exposes all registered services, including XML-RPC""", 'http://127.0.0.1:8000/mywiki/default/call/xmlrpc', # Make sure this is called after the auth instance is created, # and before any change to the wiki tables, # Place this after auth object initialization. The best way to install web2py is to clone the git repository.Be sure to follow the instructions in the readme so you clone all the dependencies recursively. This means that, in this case, one smartgrid can create a grid for parent and one grid for child. images is iterable and its elements are the selected rows. For example: Mind that by default English is not translated because web2py assumes the applications are written in English. Here is an example of a validator on a database table: where we have used the translation operator T to allow for internationalization. Both SQLFORM and CRUD provides a utility to version database records: If you have a table (db.mytable) that needs full revision history you can just do: auth.archive defines a new table called db.mytable_archive (the name is derived from the name of the table to which it refers) and on updating, it stores a copy of the record (as it was before the update) in the created archive table, including a reference to the current record. If you pass a record as the optional second argument to the SQLFORM constructor, the form becomes an UPDATE form for that record. Multiple references are handled automatically in create and update forms, but they are transparent to the DAL. Just append the following action to the default controller: you see the feed (the exact output depends on the feed reader). Lines 5-7 loop over the image rows and for each row image display: This is a
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tag that contains an ... tag which contains the image.title. Let's now add a counter to this page that will count how many times the same visitor displays the page. If set to True multiple values can be stored in one field. The wizard will guide you through a series of steps involved in creating a new application: The image below shows the second step of the process. Different visitors see different counters. When you click on a table name in appadmin, web2py performs a select of all records on the current table, identified by the DAL query. The session is a container for variables that are stored server-side. Named arguments starting with an underscore (for example _href) are interpreted as tag attributes but without the underscore. i.e. If you cut and paste @////15/beach.jpg into wiki pages you embed the image. The process function takes some extra argument that accepts does not take: onsuccess and onfailure can be functions like lambda form: do_something(form). Copyright © 2021 by Massimo Di Pierro, Here is the "default/form_from_factory.html" view: You cannot use space into field names, set labels explicitly in field constructors (i.e. Line 15 requires that the field "image_id" of table "post" is in db.image.id. Field('field_name', ..., label='...')) or pass a dictionary of labels to form_factory, as you would for a SQLFORM. The form may have additional options that link other web pages. This validator matches the value against a regular expression and returns an error if it does not match. using LOAD(). The code is shown at the bottom of the same page. This field should be of type list:reference as discussed in Chapter 6. They are called in the order in which they are listed. We will also add a counter that counts how many times the same user visits the page. If there are comments, it loops over them and displays each one. In a model, for example "db.py", we need to add: In our controller, we need to add one action: This is sufficient to enable login, register, logout, etc. In fact, the "static/css/web2py.css" stylesheet is well documented and described in Chapter 5. Consider the following tables and requirement: the IS_IN_DB requirement could also be written to use a Set instead of db. The interface of the wizard will change over time to include support for more features and easier visual development. Edit the "db.py" file by clicking the corresponding "edit" button: Line 1 defines a global variable called db that represents the database connection. Then choose a slug (in the publishing business, a slug is a short name given to an article that is in production) and you will be redirected to an empty page where you can edit the content using MARKMIN wiki syntax. The form should be accepted if the choice is accepted, that is on submission only. Nevertheless, de-compilation can be difficult and can be illegal. The complete signature for the grid is the following: In versions of web2py after 2.6, virtual fields are shown in grids like normal fields: either shown alongside all other fields by default, or by including them in the fields argument. Assuming. All of this is done under the hood and hidden to the developer. Line 37 creates a grid object that allows to view, add and update the comments linked to a page. ), but they are not listed on the edit page because they are not created or modified by the administrator; they are created and modified by the application itself. A complete argument list for IS_NOT_IN_DB() is as follows: The following code, for example, does not allow registration of two persons with the same name within 10 days of each other: where the third and fourth arguments are optional. If there is no dot present, extension checks will be done against empty string and filename checks against whole value. If you click on delete, you can delete the file (permanently). The optional argument keepvalues tells web2py what to do when a form is accepted and there is no redirection, so the same form is displayed again. Note that Python (as any other programming language) can technically be decompiled; therefore compilation does not provide complete protection of the source code. This validator takes a list of validators and accepts a value if any of the validators in the list does (i.e. For example: Notice that since both "page_one" and "page_two" use the same form, we have defined it only once by placing it outside of all the actions, in order not to repeat ourselves. It is possible to have multiple forms per page, but you must allow web2py to distinguish them. web2py comes with powerful functions for form generation. It returns a string that the browser displays for us. beach is the title. It just converts the value to lower case. By default generic views are only allowed from localhost for development purposes. Works for both text and file inputs. Sometimes, though, you don't have a choice, because the action that sends the form and the action that receives it belong to different applications. They are rendered as INPUT fields of type="file". It must perform the opposite conversion to the one the __call__ does. This is illustrated in the following screenshot: The interactive console also serves as a python scratchpad. We call this a component. In this example, we use IS_IN_DB in a controller to limit the records dynamically each time the controller is called: If you want the field validated, but you do not want a drop-down, you must put the validator in a list. causes the hidden fields to be passed with the submission, no more, no less. This data is presented to the administrator as charts under the application "about" page. the index action in the default controller of the myapp application is called. The archive table name and/or reference field name can be changed like this: If a form is created with SQLFORM, SQLFORM.factory or CRUD, there are multiple ways it can be embedded in a view allowing multiple degrees of customization. The index action performs a select of all fields (db.image.ALL) from table image, ordered by db.image.title. So, args=request.args[:1] tells the grid to preserve the first URL argument in any links that it generates, appending any grid-specific arguments after that first argument. Older versions of web2py used md5 or HMAC+SHA512 depending on whether a key was specified or not. There are two possible uses for the autocomplete widget: to autocomplete a field that takes a value from a list or to autocomplete a reference field (where the string to be autocompleted is a representation of the reference which is implemented as an id). You can provide a regular expression for the matching of the empty string with the empty_regex argument (like for IS_NOT_EMPTY validator). The attributes of the input tags are specified by the named arguments starting with underscore. sets the log message on successful record deletion. Your code is likely to include hardcoded strings such as "What is your name?". The value returned by accepts is stored in form.accepted. You access it via the "database administration" link in the edit page or directly: Here is a screenshot of the appadmin interface: This interface is coded in the controller called "appadmin.py" and the corresponding view "appadmin.html". Here is an example of usage: The first argument of SQLFORM.grid can be a table or a query. By setting sanitize=True, you tell web2py to escape unsafe XML tags such as "