Difference between revisions of "Using web services"

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{{Moodle_2.0}}This document explains how an administrator can set up a web service for users to access a service. All users will have a specific and unique security key (also known as a "token") to access the service. Each user will normally enter their own security key into an external application.
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{{Web services}}
 
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This document explains how an administrator can set up a web service for users to access a service. Each user will have a specific and unique security key (also known as a "token") to access the service.
  
 
== Enabling web services==
 
== Enabling web services==
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== Enabling web service function documentation ==
 
== Enabling web service function documentation ==
[[Image:Web services documentation.jpg|thumb|Enabling web service function documentation]]
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[[Image:Security keys and documentation.jpg|thumb|Security keys page with documentation link]]
 
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Enabling web service function documentation (also on the Manage protocols page) results in user-specific web service documentation being available for each user on their [[Security keys]] page. This option is mainly useful to web service client developers. If nobody is creating a web service client, there is no need to enable this feature.
Enabling web service function documentation (also on the Manage protocols page) results in user-specific web service descriptions being available for each user on their [[How_to_get_a_security_key|security keys]] page. This option is mainly useful to web service client developers. If nobody is creating a web service client, there is no need to enable this feature.
 
  
 
== Creating a service ==
 
== Creating a service ==
[[Image:Add external service.jpg|thumb|left|Creating a service]]There are no default web services in Moodle so it is necessary to create a custom service i.e. select which of the standard web service functions are available via that service.
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If none of the pre-build web services match your needs, you can create a custom service i.e. select which of the standard web service functions are available via that service.
  
 
You can enable only the specific functions that you need to expose, so not compromising on security.
 
You can enable only the specific functions that you need to expose, so not compromising on security.
 
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[[Image:Create a service.jpg|thumb|Creating a service|left]]
 
# Access ''Settings > Site administration > Plugins > Web services > External services''
 
# Access ''Settings > Site administration > Plugins > Web services > External services''
 
# Click Add new custom service
 
# Click Add new custom service
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#* 'Authorised users only' - If enabled, you will need to select the authorised users manually. Otherwise all users with appropriate permissions are allowed
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#* 'Required capability' - If enabled, any user accessing the web service will be checked against this selected capability. (This is just an additional optional security layer.)
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# Enter a name and check Enabled
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# Click the button 'Add service'
  
[[Image:Create a service.jpg|thumb]]The ''Add a service'' page should be displayed.
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==Adding functions to the service==
 
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[[Image:Select a web service function.jpg|thumb|Adding functions to the service]]Your service is currently empty and doesn't do anything. Web service functions need to be added. Your choice will be dictated by what you allow the external application to do. For this example, select 'Create group'.
*  "''Authorised users only''": if enabled, you will need to select the authorised users manually. Otherwise all Moodle users are allowed, at the condition they have the [https://docs.moodle.org/en/How_to_enable_web_services_for_ordinary_users#Enable_capabilities_to_users right permissions]
 
* ''required capability'': if enabled, any user accessing the web service will be checked against this selected capability. It is just an additional and optional security layer for your own usage.
 
 
 
  Enter a ''name'' and check ''enable''
 
  Uncheck ''Authorised users only'' and ''required capability''
 
  Click on '''Add service'''
 
 
 
= Add functions to the service =
 
[[Image:Add functions to the service.jpg|thumb]][[Image:Select a web service function.jpg|thumb]]At this moment your service is empty and doesn't do much. You want to add some web service function to it. Your choice will be dictated by what you allow the external application to do. For now you are going to select 'Create group' function for the only reason that it is the function used as example to [https://docs.moodle.org/en/Development:Creating_a_web_service_client create a web service client].
 
 
 
  Click '''Add functions''' link,
 
  Select 'create group' function and click '''Add functions''' button
 
 
 
[[Image:Function added-1.jpg|thumb]]You should be back to the service function list. Next to each function you can see a 'Required capabilies' field. Users need these capabilities to run each function. However there is some exception. Sometimes a function use case could not require the entire capability list. The only way to be 100% sure is to read the web service function documentation (even though they are currently not indicated see MDL-XXX). Core developers try to keep capability names clear enough that it should straight forward for administrator to guess it right.
 
 
 
 
 
 
 
 
 
 
 
  
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# Click 'Add functions' link
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# Select 'create group' function and click the 'Add functions' button
  
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You should be back to the service functions list. 'Required capabilities' are indicated for each function. Users need the required capabilities to run a function. The function descriptions in the API Documentation can also give you more information about the required capabilities (''Settings > Site administration > Plugins > Web services > API Documentation'').
  
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==Enabling capabilities==
  
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The final step is to grant appropriate permissions. The following capabilities should be allowed:
  
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* [[Capabilities/moodle/webservice:createtoken|moodle/webservice:createtoken]] - for allowing users to generate a security key
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* [[Capabilities/webservice/rest:use | webservice/rest:use]], [[Capabilities/webservice/soap:use | webservice/soap:use]], [[Capabilities/webservice/xmlrpc:use | webservice/xmlrpc:use]], [[Capabilities/webservice/amf:use | webservice/amf:use]] which match the enabled protocols.
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* The service ''Required capability'' if set (''Settings > Site administration > Plugins > Web services > Manage services >'''Edit''' link'').
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* The required capabilities for the web service functions. These required capabilities are listed when you add a function to the service. For more information about roles and capabilities, read the [[Manage roles]] documentation.
  
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Once done, the web service should be set up. Users should be able to [[Security keys|obtain a personal security key]].
  
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= Alternative settings =
  
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== Authorise only specific users==
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[[Image:Authorised users link.jpg|thumb]] [[Image:Authorised user selection page.jpg|thumb]]
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# ''Settings > Site Administration > Plugins > Web services > External Services''
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# Select '''Authorised users''' link (the service must have been set as '''Authorised users only''' in the '''Edit''' link)
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# Select some users and click '''Add'''
  
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Moodle indicates if some capabilities need to be assigned to an authorised user. Moreover if you click on the authorised user fullname, you can set up some specific options: ''IP restriction'' and ''Valid until''.
  
= Enable capabilities to users=
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== Create a token  ==
The last step, and the trickiest, is to grant the right permission to the users. They would need the following capabilities:
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[[Image:Create_token.jpg|thumb]]
* "''moodle/webservice:createtoken''" so the user can generate a security key.
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This feature allows you to create a token for specific user. It can be useful if a user doesn't have the moodle/create:token capability. This is also the only way to create a token for an administrator. For security reason, tokens are not automatically generated in the administrator security  keys page.
* "''webservice/rest:use'', ''webservice/soap:use'', ''webservice/xmlrpc:use'', ''webservice/amf:use''" matching the enabled protocols.
 
* the required capabilities by the web service functions. These required capabilities are listed when you add a function to the service.
 
For more information about roles and capabilities, read the [https://docs.moodle.org/en/Manage_roles Manage roles] documentation.
 
  
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# ''Settings > Site Administration > Plugins > Web services > Manage tokens''
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# Click on '''Add'''
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# Select the created user and service
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# Click on '''Saves changes'''
  
[[Image:Security keys and documentation.jpg|thumb]]Once done, the web service should be set up. The user can [https://docs.moodle.org/en/How_to_get_a_security_key retrieve his/her personal security key] and copy it in an external application.
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As you created a token for this user, you do not need to assign "''moodle/webservice:createtoken''" to him/her.
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Finally, note that, as for authorised users, you can also set ''IP restriction'' and ''Valid until'' on a token.
  
= See also=
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== See also ==
* [https://docs.moodle.org/en/Web_Services Web services]
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* [[How to enable web services for an external system]]
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*[http://www.joomdle.com/wiki/Preparing_Moodle_20#Setting_up_Moodle_Web_services Joomdle documentation about setting Moodle web services]
  
[[Category:Web Services]]
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[[de:Webservices nutzen]]

Latest revision as of 15:53, 13 June 2012

This document explains how an administrator can set up a web service for users to access a service. Each user will have a specific and unique security key (also known as a "token") to access the service.

Enabling web services

Enabling web services
  1. Access Settings > Site administration > Advanced features
  2. Check 'Enable web services' then click 'Save Changes'

Note: For security reasons, web services should only be enabled if you intend to make use of it.

Enabling protocols

Enabling protocols

Usually external applications that users wish to use dictate which protocols should be enabled.

  1. Access Settings > Site administration > Plugins > Web services > Manage protocols
  2. Enable the protocols (SOAP, REST, XMLRPC, AMF, ...) as required

Enabling web service function documentation

Security keys page with documentation link

Enabling web service function documentation (also on the Manage protocols page) results in user-specific web service documentation being available for each user on their Security keys page. This option is mainly useful to web service client developers. If nobody is creating a web service client, there is no need to enable this feature.

Creating a service

If none of the pre-build web services match your needs, you can create a custom service i.e. select which of the standard web service functions are available via that service.

You can enable only the specific functions that you need to expose, so not compromising on security.

Creating a service
  1. Access Settings > Site administration > Plugins > Web services > External services
  2. Click Add new custom service
    • 'Authorised users only' - If enabled, you will need to select the authorised users manually. Otherwise all users with appropriate permissions are allowed
    • 'Required capability' - If enabled, any user accessing the web service will be checked against this selected capability. (This is just an additional optional security layer.)
  3. Enter a name and check Enabled
  4. Click the button 'Add service'

Adding functions to the service

Adding functions to the service
Your service is currently empty and doesn't do anything. Web service functions need to be added. Your choice will be dictated by what you allow the external application to do. For this example, select 'Create group'.
  1. Click 'Add functions' link
  2. Select 'create group' function and click the 'Add functions' button

You should be back to the service functions list. 'Required capabilities' are indicated for each function. Users need the required capabilities to run a function. The function descriptions in the API Documentation can also give you more information about the required capabilities (Settings > Site administration > Plugins > Web services > API Documentation).

Enabling capabilities

The final step is to grant appropriate permissions. The following capabilities should be allowed:

Once done, the web service should be set up. Users should be able to obtain a personal security key.

Alternative settings

Authorise only specific users

Authorised users link.jpg
Authorised user selection page.jpg
  1. Settings > Site Administration > Plugins > Web services > External Services
  2. Select Authorised users link (the service must have been set as Authorised users only in the Edit link)
  3. Select some users and click Add

Moodle indicates if some capabilities need to be assigned to an authorised user. Moreover if you click on the authorised user fullname, you can set up some specific options: IP restriction and Valid until.

Create a token

Create token.jpg

This feature allows you to create a token for specific user. It can be useful if a user doesn't have the moodle/create:token capability. This is also the only way to create a token for an administrator. For security reason, tokens are not automatically generated in the administrator security keys page.

  1. Settings > Site Administration > Plugins > Web services > Manage tokens
  2. Click on Add
  3. Select the created user and service
  4. Click on Saves changes

As you created a token for this user, you do not need to assign "moodle/webservice:createtoken" to him/her. Finally, note that, as for authorised users, you can also set IP restriction and Valid until on a token.

See also