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135 lines
4.2 KiB
Plaintext
135 lines
4.2 KiB
Plaintext
This package installs the Google APIs in Free Pascal 3.1 in the lazarus
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component palette.
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Each Google Service API is a REST API that offers multiple resources.
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See the end of this file for instructions for compiling with FPC 2.6.x
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==================
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Component overview
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==================
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A Google API breaks down in 4 parts, all of which have a base class in the
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following units:
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TGoogleClient - unit googleclient
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---------------------------------
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This is a simple component that handles the transport and authorization,
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it needs a TFPWebClient descendent (such as TFPHTTPWebClient, available in
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the weblaz package) and a TFPOauth2Handler descendent to communicate with
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Google servers (the component creates a default one).
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These 2 classes are part of fcl-web, a synapse-based TFPWebclient descendant
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is available separately.
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TGoogleAPI - unit googleservice
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-------------------------------
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There is a descendent of this component for each Google service API, which
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handles all calls to the service. It uses a TGoogleClient component to
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handle actual communication.
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This class contains a method called ServiceCall which is used by all
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resources in the API to execute service requests. It will use the client to
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do the actual HTTP request.
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Each unit google*.pp in this package contains a single component that
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descends from the TGoogleAPI component.
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TGoogleResource - unit googleservice
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------------------------------------
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For each resource exposed by the service, a descendent of this class is generated
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that has all the methods for that resource, as described in the REST service
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description.
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TGoogleResource uses an instance of the TGoogleAPI class to handle all calls to
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the service.
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Each API unit google*.pp in this package contains one or more
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TGoogleResource
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descendents, used in the API of that unit.
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TGoogleBaseObject - unit googlebase
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-----------------------------------
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For each data type used in the API, a descendent of this class is used: it is a
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descendent of TBaseObject (unit restbase, part of fcl-web) and handles
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loading from and saving to JSON.
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====================
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Demo programs setup.
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====================
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The demo programs create the necessary API components in code, it is
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therefor not necessary to install the lazgoogleapis package in the IDE,
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it just has to be opened and compiled.
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There are 4 demo programs. Before they can be used, they must be defined in Google.
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The following procedure is not needed for the discovery demo, it does not
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need authentication.
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You will need to:
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1. Have a google account
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2. Be registered as a google Developer. Just go to the google developer console at:
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https://console.developers.google.com/
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3. Register a new project in the console.
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4. Create a new client ID and Secret key under Credentials (APIs & Auth)
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As a redirect URI, enter: urn:ietf:wg:oauth:2.0:oob
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The Client ID and secret key must be saved in the google.ini file in the example directory:
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[Credentials]
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ClientID=Your client ID
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ClientSecret=Your secret key
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Scope=https://www.googleapis.com/auth/calendar
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The scope must match the API that is used. (the example files contain the
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correct scope)
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5. Under credentials, request credentials (under APIs) for
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Calendar API
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Drive API
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Tasks API
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You can re-use the same Client ID and secret for all examples, or you
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can create different client IDs and keys, or even create different projects.
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========================
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Compiling with FPC 2.6.4
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========================
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The code works with FPC 2.6.4. To work with FPC 2.6.4, you need the
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following files from the FPC SVN repository (trunk):
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From packages/fcl-web/src/base:
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fpoauth2.pp
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fphttpwebclient.pp
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fpwebclient.pp
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restcodegen.pp
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restbase.pp
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fpoauth2ini.pp
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fpjwt.pp
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From packages/googleapi/src
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All *.pp files
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There is a directory 2_6_4 to which the files can be copied.
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Additionally, in the directory 2_6_4 there is a unit synapsewebclient.
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This unit implements a TFPWebclient descendent that works with Synapse.
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It works with version 2.6.4, and with version 3.x of Free Pascal.
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You need to have compiled the laz_synapse package (distributed with synapse)
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for this to work.
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To compile the package and the demos, copy the needed files to directory 2_6_4 and
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add this directory to the source path of the lazgoogleapi package and all
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demo programs.
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