Tcl Requires Chilkat v11.0.0+
Tcl
Google Drive - Build a Local Cache of Metadata
See more Google Drive Examples
This example demonstrates how to download the metadata for all files in a Google Drive account to create a local filesystem cache with the information. The cache can be used to fetch information without having to query Google Drive.Chilkat Tcl Downloads
load ./chilkat.dll
set success 0
set success 1
# It requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.
# This example uses a previously obtained access token having permission for the
# Google Drive scope.
set gAuth [new_CkAuthGoogle]
CkAuthGoogle_put_AccessToken $gAuth "GOOGLE_DRIVE_ACCESS_TOKEN"
set rest [new_CkRest]
# Connect using TLS.
set bAutoReconnect 1
set success [CkRest_Connect $rest "www.googleapis.com" 443 1 $bAutoReconnect]
# Provide the authentication credentials (i.e. the access token)
CkRest_SetAuthGoogle $rest $gAuth
# -------------------------------------------------------------------
# Initialize our cache object. Indicate the location of the root cache directory, and how many cache levels are to exist.
# For small caches (level 0) all cache files are in the root directory.
# For medium caches (level 1) cache files are located in 256 sub-directories from the root.
# For large caches (level 2) cache files are located in 256x256 sub-directories two levels down from the root.
set gdCache [new_CkCache]
CkCache_put_Level $gdCache 0
# Use a root directory that makes sense on your operating system..
CkCache_AddRoot $gdCache "C:/ckCache/googleDrive"
# If we are re-building the cache, we can first delete the entire contents of the cache.
set numCacheFilesDeleted [CkCache_DeleteAll $gdCache]
# Create a date/time object with an time 7 days from the current date/time.
set dtExpire [new_CkDateTime]
CkDateTime_SetFromCurrentSystemTime $dtExpire
CkDateTime_AddDays $dtExpire 7
# Indicate that we want ALL possible fields.
# If no fields are indicated, then only the basic fields are returned.
set allFields "appProperties,capabilities,contentHints,createdTime,description,explicitlyTrashed,fileExtension,folderColorRgb,fullFileExtension,headRevisionId,iconLink,id,imageMediaMetadata,isAppAuthorized,kind,lastModifyingUser,md5Checksum,mimeType,modifiedByMeTime,modifiedTime,name,originalFilename,ownedByMe,owners,parents,permissions,properties,quotaBytesUsed,shared,sharedWithMeTime,sharingUser,size,spaces,starred,thumbnailLink,trashed,version,videoMediaMetadata,viewedByMe,viewedByMeTime,viewersCanCopyContent,webContentLink,webViewLink,writersCanShare"
# We're going to keep a master list of fileId's as we iterate over all the files in this Google Drive account.
# This master list will also be saved to the cache under the key "AllGoogleDriveFileIds".
set jsonMaster [new_CkJsonObject]
set jsonMasterArr [new_CkJsonArray]
CkJsonObject_AppendArray2 $jsonMaster "fileIds" $jsonMasterArr
# Also keep a list of file paths.
set jsonMasterPaths [new_CkJsonArray]
CkJsonObject_AppendArray2 $jsonMaster "filePaths" $jsonMasterPaths
# The default page size is 100, with a max of 1000.
CkRest_AddQueryParam $rest "pageSize" "200"
set json [new_CkJsonObject]
# jsonFileMetadata is a CkJsonObject
# Send the request for the 1st page.
set jsonResponse [CkRest_fullRequestNoBody $rest "GET" "/drive/v3/files"]
set pageNumber 1
set bContinueLoop [expr [CkRest_get_LastMethodSuccess $rest] && [[CkRest_get_ResponseStatusCode $rest] == 200]]
while {$bContinueLoop == 1} {
puts "---- Page $pageNumber ----"
CkJsonObject_Load $json $jsonResponse
set numFiles [CkJsonObject_SizeOfArray $json "files"]
set i 0
while {$i < $numFiles} {
# Add this file ID to the master list.
CkJsonObject_put_I $json $i
CkJsonArray_AddStringAt $jsonMasterArr -1 [CkJsonObject_stringOf $json "files[i].id"]
set i [expr $i + 1]
}
# Get the next page of files.
# If the "nextPageToken" is present in the JSON response, then use it in the "pageToken" parameter
# for the next request. If no "nextPageToken" was present, then this was the last page of files.
set pageToken [CkJsonObject_stringOf $json "nextPageToken"]
set bContinueLoop 0
set bHasMorePages [CkJsonObject_get_LastMethodSuccess $json]
if {$bHasMorePages == 1} then {
CkRest_ClearAllQueryParams $rest
CkRest_AddQueryParam $rest "pageSize" "200"
CkRest_AddQueryParam $rest "pageToken" $pageToken
set jsonResponse [CkRest_fullRequestNoBody $rest "GET" "/drive/v3/files"]
set bContinueLoop [expr [CkRest_get_LastMethodSuccess $rest] && [[CkRest_get_ResponseStatusCode $rest] == 200]]
set pageNumber [expr $pageNumber + 1]
}
}
# Check to see if the above loop exited with errors...
if {[CkRest_get_LastMethodSuccess $rest] == 0} then {
puts [CkRest_lastErrorText $rest]
delete_CkAuthGoogle $gAuth
delete_CkRest $rest
delete_CkCache $gdCache
delete_CkDateTime $dtExpire
delete_CkJsonObject $jsonMaster
delete_CkJsonArray $jsonMasterArr
delete_CkJsonArray $jsonMasterPaths
delete_CkJsonObject $json
exit
}
# Check to see if the above loop exited with errors...
# A successful response will have a status code equal to 200.
if {[CkRest_get_ResponseStatusCode $rest] != 200} then {
puts "response status code = [CkRest_get_ResponseStatusCode $rest]"
puts "response status text = [CkRest_responseStatusText $rest]"
puts "response header: [CkRest_responseHeader $rest]"
puts "response JSON: $jsonResponse"
delete_CkAuthGoogle $gAuth
delete_CkRest $rest
delete_CkCache $gdCache
delete_CkDateTime $dtExpire
delete_CkJsonObject $jsonMaster
delete_CkJsonArray $jsonMasterArr
delete_CkJsonArray $jsonMasterPaths
delete_CkJsonObject $json
exit
}
# Iterate over the file IDs and download the metadata for each, saving each to the cache...
# Also, keep in-memory hash entries of the name and parent[0] so we can quickly
# build the path-->fileId cache entries. (Given that the Google Drive REST API uses
# fileIds, this gives us an easy way to lookup a fileId based on a filePath.)
set hashTable [new_CkHashtable]
# Set the capacity of the hash table to something reasonable for the number of files
# to be hashed.
CkHashtable_ClearWithNewCapacity $hashTable 521
set sbPathForFileId [new_CkStringBuilder]
# Used for storing the file name and parents[0] in the hashTable.
set saFileInfo [new_CkStringArray]
CkStringArray_put_Unique $saFileInfo 0
set numFiles [CkJsonObject_SizeOfArray $jsonMaster "fileIds"]
set i 0
while {$i < $numFiles} {
CkJsonObject_put_I $jsonMaster $i
set fileId [CkJsonObject_stringOf $jsonMaster "fileIds[i]"]
CkStringBuilder_SetString $sbPathForFileId "/drive/v3/files/"
CkStringBuilder_Append $sbPathForFileId $fileId
CkRest_ClearAllQueryParams $rest
CkRest_AddQueryParam $rest "fields" $allFields
set jsonResponse [CkRest_fullRequestNoBody $rest "GET" [CkStringBuilder_getAsString $sbPathForFileId]]
if {expr [[CkRest_get_LastMethodSuccess $rest] != 1] || [[CkRest_get_ResponseStatusCode $rest] != 200]} then {
# Force an exit of this loop..
set numFiles 0
}
# Save this file's metadata to the local cache.
# The lookup key is the fileId.
CkCache_SaveTextDt $gdCache $fileId $dtExpire "" $jsonResponse
# Get this file's name and parent[0], and put this information
# in our in-memory hashtable to be used below..
CkJsonObject_Load $json $jsonResponse
CkStringArray_Clear $saFileInfo
CkStringArray_Append $saFileInfo [CkJsonObject_stringOf $json "name"]
CkStringArray_Append $saFileInfo [CkJsonObject_stringOf $json "parents[0]"]
CkHashtable_AddStr $hashTable $fileId [CkStringArray_serialize $saFileInfo]
puts [CkJsonObject_stringOf $json name], [CkJsonObject_stringOf $json {parents[0]}]
set i [expr $i + 1]
}
# Check to see if the above loop exited with errors...
if {[CkRest_get_LastMethodSuccess $rest] == 0} then {
puts [CkRest_lastErrorText $rest]
delete_CkAuthGoogle $gAuth
delete_CkRest $rest
delete_CkCache $gdCache
delete_CkDateTime $dtExpire
delete_CkJsonObject $jsonMaster
delete_CkJsonArray $jsonMasterArr
delete_CkJsonArray $jsonMasterPaths
delete_CkJsonObject $json
delete_CkHashtable $hashTable
delete_CkStringBuilder $sbPathForFileId
delete_CkStringArray $saFileInfo
exit
}
# Check to see if the above loop exited with errors...
# A successful response will have a status code equal to 200.
if {[CkRest_get_ResponseStatusCode $rest] != 200} then {
puts "response status code = [CkRest_get_ResponseStatusCode $rest]"
puts "response status text = [CkRest_responseStatusText $rest]"
puts "response header: [CkRest_responseHeader $rest]"
puts "response JSON: $jsonResponse"
delete_CkAuthGoogle $gAuth
delete_CkRest $rest
delete_CkCache $gdCache
delete_CkDateTime $dtExpire
delete_CkJsonObject $jsonMaster
delete_CkJsonArray $jsonMasterArr
delete_CkJsonArray $jsonMasterPaths
delete_CkJsonObject $json
delete_CkHashtable $hashTable
delete_CkStringBuilder $sbPathForFileId
delete_CkStringArray $saFileInfo
exit
}
# Now that all the fileId's are in the cache, let's build the directory path
# for each fileID.
# (Technically, a fileId can have multiple parents, which means it can be in multiple directories
# at once. This is only going to build directory paths following the 0'th parent ID in the parents list.)
# The directory path for files in "My Drive" will be just the filename.
# For files in sub-directories, the path will be relative, such as "subdir1/subdir2/something.pdf"
#
puts "---- building paths ----"
set sbPath [new_CkStringBuilder]
set numFiles [CkJsonObject_SizeOfArray $jsonMaster "fileIds"]
set i 0
while {$i < $numFiles} {
CkJsonObject_put_I $jsonMaster $i
CkStringBuilder_Clear $sbPath
set fileId [CkJsonObject_stringOf $jsonMaster "fileIds[i]"]
set bFinished 0
while {$bFinished == 0} {
CkStringArray_Clear $saFileInfo
CkStringArray_AppendSerialized $saFileInfo [CkHashtable_lookupStr $hashTable $fileId]
# Append this file or directory name.
CkStringBuilder_Prepend $sbPath [CkStringArray_getString $saFileInfo 0]
# Get the parent fileId
set fileId [CkStringArray_getString $saFileInfo 1]
# If this fileId is not in the hashtable, then it's the fileId for "My Drive", and we are finished.
if {[CkHashtable_Contains $hashTable $fileId] == 0} then {
set bFinished 1
} else {
CkStringBuilder_Prepend $sbPath "/"
}
}
puts "$i: [CkStringBuilder_getAsString $sbPath]"
# Store the filePath --> fileId mapping in our local cache.
set fileId [CkJsonObject_stringOf $jsonMaster "fileIds[i]"]
CkCache_SaveTextDt $gdCache [CkStringBuilder_getAsString $sbPath] $dtExpire "" $fileId
CkJsonArray_AddStringAt $jsonMasterPaths -1 [CkStringBuilder_getAsString $sbPath]
set i [expr $i + 1]
}
# Save the master list of file IDs and file paths to the local cache.
CkJsonObject_put_EmitCompact $jsonMaster 0
set strJsonMaster [CkJsonObject_emit $jsonMaster]
CkCache_SaveTextNoExpire $gdCache "AllGoogleDriveFileIds" "" $strJsonMaster
puts "JSON Master Record:"
puts "$strJsonMaster"
# The JSON Master Cache Record looks something like this:
# An application can load the JSON master record and iterate over all the files
# in Google Drive by file ID, or by path.
# {
# "fileIds": [
# "0B53Q6OSTWYolQlExSlBQT1phZXM",
# "0B53Q6OSTWYolVHRPVkxtYWFtZkk",
# "0B53Q6OSTWYolRGZEV3ZGUTZfNFk",
# "0B53Q6OSTWYolS2FXSjliMXQxSU0",
# "0B53Q6OSTWYolZUhxckMzb0dRMzg",
# "0B53Q6OSTWYolbUF6WS1Gei1oalk",
# "0B53Q6OSTWYola296ODZUSm5GYU0",
# "0B53Q6OSTWYolbTE3c3J5RHBUcHM",
# "0B53Q6OSTWYolTmhybWJSUGd5Q2c",
# "0B53Q6OSTWYolY2tPU1BnYW02T2c",
# "0B53Q6OSTWYolTTBBR2NvUE81Zzg",
# ],
# "filePaths": [
# "testFolder/abc/123/pigs.json",
# "testFolder/starfish20.jpg",
# "testFolder/penguins2.jpg",
# "testFolder/starfish.jpg",
# "testFolder/abc/123/starfish.jpg",
# "testFolder/abc/123/penguins.jpg",
# "testFolder/abc/123",
# "testFolder/abc",
# "testFolder/testHello.txt",
# "testFolder",
# "helloWorld.txt",
# ]
# }
puts "Entire cache rebuilt..."
delete_CkAuthGoogle $gAuth
delete_CkRest $rest
delete_CkCache $gdCache
delete_CkDateTime $dtExpire
delete_CkJsonObject $jsonMaster
delete_CkJsonArray $jsonMasterArr
delete_CkJsonArray $jsonMasterPaths
delete_CkJsonObject $json
delete_CkHashtable $hashTable
delete_CkStringBuilder $sbPathForFileId
delete_CkStringArray $saFileInfo
delete_CkStringBuilder $sbPath