C# Requires Chilkat v11.5.0+
C#
Box: Reuse HttpCurl and Invalidate Cached IDs
See more Box Examples
Run the reusable setup once per HttpCurl object, then select names and execute the operation. The setup is repeated here only to make this published example independently runnable. Perform three operations with one configured object: cold file lookup, warm download without lookups, then another download after clearing only file state. No functions are re-registered. Rebind an AddOutput2 filter whenever its selected name changes.
See the Box API guide for setup and the complete workflow.
Chilkat C# Downloads
bool success = false;
// Requires Chilkat 11.5.0 or later and a previously unlocked Chilkat bundle.
// See Global Unlock Sample.
// Guide: Box API Guide.
success = false;
// BEGIN ONE-TIME SETUP
// This block is repeated so each published example can run on its own.
// In an application, run the setup example once and pass the SAME curl object
// to operation code below. Do not recreate it for every operation.
// See Reusable Box HttpCurl Setup.
Chilkat.HttpCurl curl = new Chilkat.HttpCurl();
curl.SetVar("access_token","BOX_ACCESS_TOKEN");
curl.SetVar("parent_name","/");
curl.SetVar("folder_name","images");
curl.SetVar("file_name","penguins.jpg");
curl.SetVar("destination_name","archive");
// Box's fixed root ID is an implementation detail; callers supply names.
curl.SetVar("parent_id","0");
Chilkat.StringBuilder setupCommand = new Chilkat.StringBuilder();
int setupReplacements;
// Register findParent; registration sends no request.
setupCommand.SetString("curl -X GET \"https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name\" -H \"Authorization: Bearer ACCESS_TOKEN\"");
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"));
success = curl.AddFunction("findParent",setupCommand.GetAsString());
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
// Register findFolder; registration sends no request.
setupCommand.SetString("curl -X GET \"https://api.box.com/2.0/folders/{{parent_id}}/items?limit=1000&fields=id,type,name\" -H \"Authorization: Bearer ACCESS_TOKEN\"");
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"));
success = curl.AddFunction("findFolder",setupCommand.GetAsString());
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
// Register findFile; registration sends no request.
setupCommand.SetString("curl -X GET \"https://api.box.com/2.0/folders/{{folder_id}}/items?limit=1000&fields=id,type,name\" -H \"Authorization: Bearer ACCESS_TOKEN\"");
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"));
success = curl.AddFunction("findFile",setupCommand.GetAsString());
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
// Register findDestination; registration sends no request.
setupCommand.SetString("curl -X GET \"https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name\" -H \"Authorization: Bearer ACCESS_TOKEN\"");
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"));
success = curl.AddFunction("findDestination",setupCommand.GetAsString());
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
// Register getFileDetails; registration sends no request.
setupCommand.SetString("curl -X GET \"https://api.box.com/2.0/files/{{file_id}}?fields=id,sha1,file_version\" -H \"Authorization: Bearer ACCESS_TOKEN\"");
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"));
success = curl.AddFunction("getFileDetails",setupCommand.GetAsString());
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
// Register getEnterprise; registration sends no request.
setupCommand.SetString("curl -X GET \"https://api.box.com/2.0/users/me?fields=enterprise\" -H \"Authorization: Bearer ACCESS_TOKEN\"");
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"));
success = curl.AddFunction("getEnterprise",setupCommand.GetAsString());
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
// Initial name selections. AddOutput2 stores these WHERE values literally.
success = curl.AddOutput2("findParent","entries","name",curl.GetVar("parent_name"),true,"id","parent_id");
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
success = curl.AddOutput2("findFolder","entries","name",curl.GetVar("folder_name"),true,"id","folder_id");
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
success = curl.AddOutput2("findFile","entries","name",curl.GetVar("file_name"),true,"id","file_id");
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
success = curl.AddOutput2("findDestination","entries","name",curl.GetVar("destination_name"),true,"id","destination_id");
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
success = curl.AddOutput("getFileDetails","file_version.id","file_version_id");
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
success = curl.AddOutput("getFileDetails","sha1","file_sha1");
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
success = curl.AddOutput("getEnterprise","enterprise.id","enterprise_id");
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
// END ONE-TIME SETUP
// The name lookups below assume each listing fits in one page (1000 items).
// Parent and destination names select root children; folder_name selects a child
// of parent_name. "/" selects the root parent. These are not arbitrary paths.
// BEGIN OPERATION -- keep the configured object when reusing it.
// Inputs are names. Retain cached IDs when the selected names have not changed.
string parentName = "/";
string folderName = "images";
string fileName = "penguins.jpg";
if ((curl.GetVar("parent_name") != parentName) || ((parentName == "/") && (curl.VarDefined("parent_id") == false))) {
curl.SetVar("parent_name",parentName);
curl.ClearVar("parent_id");
curl.ClearVar("folder_id");
curl.ClearVar("file_id");
curl.ClearVar("file_version_id");
curl.ClearVar("file_sha1");
if (parentName == "/") {
curl.SetVar("parent_id","0");
}
else {
success = curl.AddOutput2("findParent","entries","name",curl.GetVar("parent_name"),true,"id","parent_id");
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
}
}
if (curl.GetVar("folder_name") != folderName) {
curl.SetVar("folder_name",folderName);
curl.ClearVar("folder_id");
curl.ClearVar("file_id");
curl.ClearVar("file_version_id");
curl.ClearVar("file_sha1");
success = curl.AddOutput2("findFolder","entries","name",curl.GetVar("folder_name"),true,"id","folder_id");
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
}
if (curl.GetVar("file_name") != fileName) {
curl.SetVar("file_name",fileName);
curl.ClearVar("file_id");
curl.ClearVar("file_version_id");
curl.ClearVar("file_sha1");
success = curl.AddOutput2("findFile","entries","name",curl.GetVar("file_name"),true,"id","file_id");
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
}
// Operation 1: get information by name. This resolves folder_id and file_id.
curl.ClearTargetOutput("*");
Chilkat.StringBuilder authorizedCommand1 = new Chilkat.StringBuilder();
authorizedCommand1.SetString("curl -X GET \"https://api.box.com/2.0/files/{{file_id}}?fields=id,name\" -H \"Authorization: Bearer {{access_token}}\"");
int headerReplacement1 = authorizedCommand1.Replace("{{access_token}}",curl.GetVar("access_token"));
success = curl.DoYourThing(authorizedCommand1.GetAsString());
if ((success != true) || (curl.StatusCode != 200)) {
Debug.WriteLine("Box request failed. HTTP status: " + Convert.ToString(curl.StatusCode));
Debug.WriteLine("Failure reason: " + Convert.ToString(curl.FailReason));
Debug.WriteLine(curl.ResponseBodyStr);
return;
}
// Operation 2: keep the same object and IDs. Only the final download is needed.
Chilkat.JsonObject warmPlan = new Chilkat.JsonObject();
warmPlan.EmitCompact = false;
Chilkat.StringBuilder authorizedCommand2 = new Chilkat.StringBuilder();
authorizedCommand2.SetString("curl -X GET \"https://api.box.com/2.0/files/{{file_id}}/content\" -H \"Authorization: Bearer {{access_token}}\" -L -o \"qa_output/penguins.jpg\"");
int headerReplacement2 = authorizedCommand2.Replace("{{access_token}}",curl.GetVar("access_token"));
success = curl.ExaminePlan(authorizedCommand2.GetAsString(),warmPlan);
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
Debug.WriteLine(warmPlan.Emit());
curl.ClearTargetOutput("*");
Chilkat.StringBuilder authorizedCommand3 = new Chilkat.StringBuilder();
authorizedCommand3.SetString("curl -X GET \"https://api.box.com/2.0/files/{{file_id}}/content\" -H \"Authorization: Bearer {{access_token}}\" -L -o \"qa_output/penguins.jpg\"");
int headerReplacement3 = authorizedCommand3.Replace("{{access_token}}",curl.GetVar("access_token"));
success = curl.DoYourThing(authorizedCommand3.GetAsString());
if ((success != true) || (curl.StatusCode != 200)) {
Debug.WriteLine("Box request failed. HTTP status: " + Convert.ToString(curl.StatusCode));
Debug.WriteLine("Failure reason: " + Convert.ToString(curl.FailReason));
Debug.WriteLine(curl.ResponseBodyStr);
return;
}
// Operation 3: explicitly invalidate file state, retaining the known folder.
// Here we select the same name so this demonstration needs only one real file.
// Substitute another filename to switch files in this folder.
curl.ClearVar("file_id");
curl.ClearVar("file_version_id");
curl.ClearVar("file_sha1");
curl.SetVar("file_name","penguins.jpg");
success = curl.AddOutput2("findFile","entries","name",curl.GetVar("file_name"),true,"id","file_id");
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
Chilkat.StringBuilder authorizedCommand4 = new Chilkat.StringBuilder();
authorizedCommand4.SetString("curl -X GET \"https://api.box.com/2.0/files/{{file_id}}/content\" -H \"Authorization: Bearer {{access_token}}\" -L -o \"qa_output/penguins.jpg\"");
int headerReplacement4 = authorizedCommand4.Replace("{{access_token}}",curl.GetVar("access_token"));
success = curl.ExaminePlan(authorizedCommand4.GetAsString(),warmPlan);
if (success != true) {
Debug.WriteLine(curl.LastErrorText);
return;
}
Debug.WriteLine(warmPlan.Emit());
curl.ClearTargetOutput("*");
Chilkat.StringBuilder authorizedCommand5 = new Chilkat.StringBuilder();
authorizedCommand5.SetString("curl -X GET \"https://api.box.com/2.0/files/{{file_id}}/content\" -H \"Authorization: Bearer {{access_token}}\" -L -o \"qa_output/penguins.jpg\"");
int headerReplacement5 = authorizedCommand5.Replace("{{access_token}}",curl.GetVar("access_token"));
success = curl.DoYourThing(authorizedCommand5.GetAsString());
if ((success != true) || (curl.StatusCode != 200)) {
Debug.WriteLine("Box request failed. HTTP status: " + Convert.ToString(curl.StatusCode));
Debug.WriteLine("Failure reason: " + Convert.ToString(curl.FailReason));
Debug.WriteLine(curl.ResponseBodyStr);
return;
}
// Changing parent_name invalidates parent_id, folder_id, and file state.
// Changing folder_name invalidates folder_id and file state.
// Changing destination_name invalidates destination_id.