Merge pull request #176 from jvelilla/ewf_doc

Updated EWF documentation
This commit is contained in:
Jocelyn Fiat
2017-02-12 12:00:07 +01:00
committed by GitHub
5 changed files with 35 additions and 35 deletions

View File

@@ -15,7 +15,7 @@ Nav: [Workbook](../workbook.md) :: [Handling Requests: Form/Query Parameter](../
## EWF service structure
The following code describes the basic structure of an EWF basic service that handles HTTP requests. We will need to define a Service Launcher and a Request Execution implementation.
The following code describes the basic structure of an EWF basic service that handles HTTP requests. We will need to define a `Service Launcher` and a `Request Execution` implementation.
```eiffel
class
@@ -60,7 +60,7 @@ end
```
When using the "standalone" connector (or the deprecated "nino" connector), by default the service listens on port 80, but often this port is already used by other applications, so it is recommended to use another port.
To define another port, redefine the feature `initialize' and set up a new port number using the service options (see below).
To define another port, redefine the feature `initialize` and set up a new port number using the service options (see below).
```eiffel
@@ -90,7 +90,7 @@ The **WSF_REQUEST** gives access to the incoming data; the class provides featur
The **WSF_RESPONSE** provides features to define the response with information such as HTTP status codes (10x,20x, 30x, 40x, and 50x), response headers (Content-Type, Content-Length, etc.) and obviously the body of the message itself.
**APPLICATION** is the root class of our example, it launches the application, using the corresponding connector, Which connector? this depends how you want to run it cgi, fcgi,standalone. For development is recommended to use a standalone web server written in Eiffel, and run the execution within the EiffelStudio debugger. For production fcgi (or cgi) using Apache or another popular web server.
**APPLICATION** is the root class of our example, it launches the application, using the corresponding connector, Which connector? this depends how do you want to run it `cgi`, `fcgi`, `standalone`. For development is recommended to use a standalone web server written in Eiffel, and run the execution within the EiffelStudio debugger. For production fcgi (or cgi) using Apache or another popular web server.
![Launcher Hierarchy](./Launcher Hierarchy.png "Launcher Hierarchy")
@@ -103,11 +103,11 @@ Other connectors:
**WSF_CGI_SERVICE_LAUNCHER**
**WSF_LIBFCGI_SERVICE_LAUNCHER**
A basic EWF service inherits from **WSF_DEFAULT_SERVICE**, which has a formal generic that should conform to **WSF_EXECUTION** class with a `make' creation procedure, in our case the class **APPLICATION_EXECUTION**.
A basic EWF service inherits from **WSF_DEFAULT_SERVICE**, which has a formal generic that should conform to **WSF_EXECUTION** class with a `make` creation procedure, in our case the class **APPLICATION_EXECUTION**.
The **APPLICATION_EXECUTION** class inherits from **WSF_EXECUTION** interface, which is instantiated for each incoming request. **WSF_EXECUTION** inherit from **WGI_EXECUTION** which is the low level entry point in EWF, handling each incoming request with a single procedure ```execute (req: WSF_REQUEST; res: WSF_RESPONSE) ...```.
In the **APPLICATION_EXECUTION** class class you will need to implement implement the **execute** feature, get data from the request *req* and write the response in *res*.
In the **APPLICATION_EXECUTION** class class you will need to implement the **execute** feature, get data from the request *req* and write the response in *res*.
![Execution Hierarchy](./APPLICATION_EXECUTION.png "Application Execution ")

View File

@@ -482,6 +482,7 @@ end
```
Using cURL to test the application
---
In the first call we use the ```res.redirect_now (l_engine_url)``` feature
```
@@ -697,7 +698,7 @@ take a look at constants classes such as [HTTP_MIME_TYPES](),[HTTP_HEADER_NAMES]
res.put_string (l_msg)
end
```
The class [HTTP_HEADER]() also supplies a number of convenience routines for specifying common headers, in fact the features are inherited from the class [HTTP_HEADER_MODIFIER].
The class [HTTP_HEADER]() also supplies a number of convenience routines for specifying common headers, in fact the features are inherited from the class [HTTP_HEADER_MODIFIER]().
```eiffel

View File

@@ -49,8 +49,8 @@ Client send cookies to server
## Write and Read Cookies.
To send a cookie to the client we should use the [HTTP_HEADER] class, and call ```h.put_cookie``` feature or
```h.put_cookie_with_expiration_date``` feature, see [How to set Cookies]() to learn the details, and the set it to response object [WSF_RESPONSE] as we saw previously.
To send a cookie to the client we should use the **HTTP_HEADER** class, and call ```h.put_cookie``` feature or
```h.put_cookie_with_expiration_date``` feature, see [How to set Cookies]() to learn the details, and the set it to response object **WSF_RESPONSE** as we saw previously.
We will show an example.

View File

@@ -17,17 +17,17 @@ Nav: [Workbook](../workbook.md) :: [Basic Concepts](../basics/basics.md) :: [Han
- [Examples](#examples)
An HTML Form can handle GET and POST requests.
When we use a form with method GET, the data is attached at the end of the url for example:
An HTML Form can handle `GET` and `POST` requests.
When we use a form with method `GET`, the data is attached at the end of the url for example:
>http://wwww.example.com?key1=value1&...keyn=valuen
If we use the method POST, the data is sent to the server in a different line.
If we use the method `POST`, the data is sent to the server in a different line.
Extracting form data from the server side is one of the most tedious parts. If you do it by hand, you will need
to parse the input, you'll have to URL-decode the value.
Here we will show you how to read input submitted by a user using a Form (GET and POST).
Here we will show you how to read input submitted by a user using a Form (`GET` and `POST`).
* How to handle missing values:
* client side validattion, server side validations, set default if it's a valid option.
* How to populate Eiffel objects from the request data.
@@ -56,29 +56,29 @@ EWF [WSF_REQUEST]() class, provides features to handling this form parsing autom
WSF_REQUEST.form_parameter (a_name: READABLE_STRING_GENERAL): detachable WSF_VALUE
-- Field for name `a_name'.
The values supplied to form_parameter and query_parameter are case sensitive.
The values supplied to `form_parameter` and `query_parameter` are _case_ _sensitive_.
<a name="uniform"></a>
### Read Data
The previous features, let you read the data one way for GET request and a different way for POST request. WSF_REQUEST provide a feature to read all the data in a uniform way.
The previous features, let you read the data one way for `GET` request and a different way for `POST` request. **WSF_REQUEST** provide a feature to read all the data in a uniform way.
WSF_REQUEST.item (a_name: READABLE_STRING_GENERAL): detachable WSF_VALUE
-- Variable named `a_name' from any of the variables container
-- and following a specific order: form_, query_ and path_ parameters
So, you use **WSF_REQUEST.item** feature exactly the same way for GET and POST request.
So, you can use **WSF_REQUEST.item** feature exactly the same way for `GET` and `POST` request.
>Note: if a query parameter has the same name as a form paramenter req.item will retrieve the form paramenter. Remember the precedence: form > query > path
>Note: if a query parameter has the same name as a form paramenter req.item will retrieve the form paramenter. Remember the precedence: `form` > `query` > `path`
<a name="reading_pv"></a>
## Reading Parameters and Values
Suppose we have the following HTML5 form using Method POST. This HTML5 form has client side form validation using the new HTML5 attribute, you can do the same using Javascript. So in this case if the user does not fill the fields as expected the form will not be submitted to the server.
Suppose we have the following HTML5 form using method `POST`. This HTML5 form has client side form validation using the new HTML5 `attribute`, you can do the same using Javascript. So in this case if the user does not fill the fields as expected the form will not be submitted to the server.
>Note: You want to validate on the server side because you can protect against the malicious user, who can easily bypass your JavaScript and submit dangerous input to the server.
>Note: it is recommended to validate client side input on the server side (as a double check) because you can protect against the malicious user, who can easily bypass your JavaScript and submit dangerous input to the server.
```
<h1> EWF Handling Client Request: Form example </h1>
@@ -117,7 +117,7 @@ Suppose we have the following HTML5 form using Method POST. This HTML5 form has
<a name="all_names"></a>
### How to read all parameter names
To read all the parameters names we simple call WSF_REQUEST.form_parameters.
To read all the parameters names we simple call **WSF_REQUEST.form_parameters**.
```
req: WSF_REQUEST
@@ -126,7 +126,7 @@ To read all the parameters names we simple call WSF_REQUEST.form_parameters.
<a name="single_values"></a>
### How to read single values
To read a particular parameter, a single value, for example `given-name', we simple call WSF_REQUEST.form_parameter (a_name) and we check if it's attached to WSF_STRING (represents a String parameter)
To read a particular parameter, a single value, for example `given-name`, we simple call **WSF_REQUEST.form_parameter (a_name)** and we check if it's attached to **WSF_STRING** (represents a String parameter)
```
req: WSF_REQUEST
if attached {WSF_STRING} req.form_paramenter ('given-name') as l_given_name then
@@ -140,7 +140,7 @@ To read a particular parameter, a single value, for example `given-name', we sim
### How to read multiple values
To read multiple values, for example in the case of `languages', we simple call WSF_REQUEST.form_parameter (a_name) and we check if it's attached to WSF_MULTIPLE_STRING (represents a String parameter)
To read multiple values, for example in the case of `languages`, we simple call **WSF_REQUEST.form_parameter (a_name)** and we check if it's attached to **WSF_MULTIPLE_STRING** (represents a String parameter)
```
req: WSF_REQUEST
@@ -159,16 +159,16 @@ To read multiple values, for example in the case of `languages', we simple call
-- Value missing
end
```
In this case we are handling strings values, but in some cases you will need to do a conversion, betweend the strings that came from the request to map them to your domain model.
In this case we are handling strings values, but in some cases you will need to do a conversion, between the strings that came from the request to map them to your domain model.
<a name="table_values"></a>
### How to read table values
This is particularly useful when you have a request with the following format
``` <a href="/link?tab[a]=1&tab[b]=2&tab[c]=foo"> ```
```<a href="/link?tab[a]=1&tab[b]=2&tab[c]=foo">```
To read table values, for example in the case of `tab', we simple call WSF_REQUEST.form_parameter (a_name) and we check if it's attached to WSF_TABLE.
To read table values, for example in the case of `tab`, we simple call **WSF_REQUEST.form_parameter (a_name)** and we check if it's attached to **WSF_TABLE**.
```
if attached {WSF_TABLE} req.query_parameter ("tab") as l_tab then
@@ -193,14 +193,14 @@ end
<a name="raw_data"></a>
## Reading Raw Data
You can also access the data in raw format, it means you will need to parse and url-decode it, and also you will not be able to use the previous features, by default, to enable that you need to call `req.set_raw_input_data_recorded (True)'. This feature (reading raw data) is useful if you are reading POST data with JSON or XML formats, but it's not convinient for HTML forms.
You can also access the data in raw format, it means you will need to parse and url-decode it, and also you will not be able to use the previous features, by default, to enable that, you will need to call `req.set_raw_input_data_recorded (True)`. This feature (reading raw data) is useful if you are reading `POST` data with JSON or XML formats, but it's not convinient for HTML forms.
To read raw data you need to do this
```
l_raw_data:STRING
req.set_raw_input_data_recorded (True) --
req.set_raw_input_data_recorded (True)
create l_raw_data.make_empty
req.read_input_data_into (l_raw_data)
```
@@ -211,7 +211,7 @@ To read raw data you need to do this
## Upload Files
How can we read data when the date come from an uploaded file/s?.
HTML supports a form element ```<input type="File" ... > ``` to upload a single file and ```<input type="File" ... multiplr> ``` to upload multiple files.
HTML supports a form element ```<input type="File" ... >``` to upload a single file and ```<input type="File" ... multiplr> ``` to upload multiple files.
So supose we have the following form
@@ -240,14 +240,14 @@ So supose we have the following form
</html>
```
The class WSF_REQUEST has defines mechanism to work with uploaded files. We can call the query
The class **WSF_REQUEST** has a mechanism to work with uploaded files. We can call the query
```
WSF_REQUEST.has_uploaded_file: BOOLEAN
-- Has any uploaded file?
```
to check if the request form parameters has any uploaded file, and we can call the feature
to check if the request form parameters has any uploaded file, we can call the feature
```
WSF_REQUEST.uploaded_files: ITERABLE [WSF_UPLOADED_FILE]
@@ -259,9 +259,9 @@ WSF_REQUEST.uploaded_files: ITERABLE [WSF_UPLOADED_FILE]
--| error: if /= 0 , there was an error : TODO ...
--| size: size of the file given by the http request
```
to iterate over the uploaded files if any, and the details in the class [WSF_UPLOADED_FILE].
to iterate over the uploaded files if any, and the details in the class **WSF_UPLOADED_FILE**.
The following snipet code show how to work with Uploaded files using EWF [WSF_REQUEST] class, in the example
The following snipet code show how to work with Uploaded files using EWF **WSF_REQUEST** class, in the example
we build a simple html answer with basic information, if there is not uploaded files, we send a 400 status code
and a simple message.

View File

@@ -84,7 +84,7 @@ GET http://eiffel.org/search?q=EiffelBase HTTP/1.1
Overview of the features
* HTTP method
- The function `request_method: READABLE_STRING_8` gives access to the HTTP request method, (usually GET or POST in conventional Web Applications), but with the raise of REST APIs other methods are also frequently used such as HEAD, PUT, DELETE, OPTIONS, or TRACE.
- The function `request_method: READABLE_STRING_8` gives access to the HTTP request method, (usually `GET` or `POST` in conventional Web Applications), but with the raise of REST APIs other methods are also frequently used such as `HEAD`, `PUT`, `DELETE`, `OPTIONS`, or `TRACE`.
A few functions helps determining quickly the nature of the request method:
- `is_get_request_method: BOOLEAN -- Is Current a GET request method?`
- `is_put_request_method: BOOLEAN -- Is Current a PUT request method?`
@@ -302,11 +302,10 @@ To be completed.
#### Detecting Browser Types
The User-Agent header identifies the specific browser/client that is sending the request. The following code shows a [EWF service](./headers/browser_name/application.e) that sends browser-specific responses.
The User-Agent header identifies the specific browser/client that is sending the request. The following code shows an [EWF service](./headers/browser_name/application.e) that sends browser-specific responses.
The examples uses the ideas based on the [Browser detection using the user agent](https://developer.mozilla.org/en-US/docs/Browser_detection_using_the_user_agent) article.
Basically the code check if the header user_agent exist and then call the ```browser_name (a_user_agent: READABLE_STRING_8): READABLE_STRING_32```
feature to retrieve the current browser name or Unknown in other case.
Basically the code check if the header `user_agent` exist and then call the ```browser_name (a_user_agent: READABLE_STRING_8): READABLE_STRING_32``` feature to retrieve the current browser name or Unknown in other case.
```eiffel
class