Stuart Clennett

Hi, Not sure if I'm on the right track here. I have a legacy database that has some images stored in blob fields in the database (I know). I'd like to be able to expose these images directly from the REST API, e.g. localhost:8080/rest/default/images/{id} I guess I have to set the Produces attribute to `image/jpeg` .. but what data type should I return? I've tried TBytes but although I get the bytes returned in Postman - web browsers don't load the image. Thanks

Thanks Andrea - I'll look into that.

Hi @Andrea Magni I implemented it using a simple base64 encoded string. Is there any benefit to using TStringWriter given that I may need the API to support web front ends written in a JS framework like Angular ? Thanks

Hi, I am auto-renewing the JWT token on the server (as per the TokenAutoRenew demo). Having received the JWT token string from the server how do I update the client MARSToken with that value. The properties are read-only. Thanks

HI, [Context] Request: TWebRequest; should be changed to [Context] Request: IMARSRequest; you'll need to include MARS.Core.RequestAndResponse.Interfaces in your uses clause. Regards

So I'm back to this. I'm currently thinking of using Data-URLs to get the base64 image data and embed direcly into the Angular client app. (ref: https://css-tricks.com/data-uris/ & https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URIs) Note that with the above TBytes solution I seem to get the response "[255, 0, 255, 0, 45, 56, 67 ..... ]" as text rather than raw bytes. The end point has the response type set as 'image/jpeg'

@alejandro The demo does not save the file at all. You are required to implement that. However it is quite simple. For example, in the `StoreDataAndFile` method in `Server.Resources.pas` you could use a memory stream to access the Bytes and save to a file if SameText(LParam.FieldName, 'image') and LParam.IsFile then begin Result.FileSize := Length(LParam.AsFile.Bytes); Result.FileName := LParam.AsFile.FileName; // This will save the file lStream := TMemoryStream.Create; try lStream.Write(LParam.AsFile.Bytes, Length(LParam.AsFile.Bytes)); lStream.SaveToFile(TPath.Combine(C_RootPath, TPath.GetFileName(LParam.AsFile.FileName))); finally lStream.free; end; end In this instance, `C_RootPath` is just a folder on the server where uploaded files should be saved, but you could make this dynamic based on user info in the Token for example. Hope this helps

Hi all, I've upgraded to MARS 1.4 and I'm hitting this compiler error on all my servers - including the MARSTemplate servers: [dcc32 Error] Server.Ignition.pas(86): E2010 Incompatible types: 'TBeforeHandleRequestProc' and 'Procedure' This is in response to the following: FEngine.BeforeHandleRequest := function (const AEngine: TMARSEngine; const AURL: TMARSURL; const ARequest: TWebRequest; const AResponse: TWebResponse; var Handled: Boolean ): Boolean begin Result := True; { code snip } end; which is in class constructor TServerEngine.CreateEngine. I'm not that great with anonymous methods & can't figure this one out. Thanks in advance,

Excellent news & thanks for the merge.

Thanks @Andrea Magni - I spotted the difference immediately after posting my question. Just going through and updating my servers now. Hope you're all safe & well.

FIXED. The function signature now uses IMARSResponse and IMARSRequest from MARS.Core.ResponseAndRequest.Interfaces D'oh 🙂

Hi, Is there anyway I can use a TFDQuery owned by a TDataModule with the resource result type TFDDataset (produces TMediaType.Application_JSON) ? At present MARS adds the FDQuery to the Activation context, so it tries to free it & it's already freed when the Datamodule is freed (as part of the resource cleanup) in the TMARSActivation.Invoke, e.g. function TAssessmentResource.GetAssessment(const id: string): TFDDataSet; begin // result := FData.qryAssessmentProperties; <-- results in Invalid Pointer Operation (FData is private DataModule) result := FD.CreateQuery(SQL_ASSESSMENT_PROPERTIES, nil, True, 'assessmentProperties'); TFDQuery(result).Params[0].AsString := id; end; The cause is as below: procedure TMARSActivation.Invoke; // [..snip..] begin try // [ ... invoke code ... ] finally // teardown phase FTeardownTime := TStopwatch.StartNew; if Assigned(FResourceInstance) then FResourceInstance.Free; //<-- datamodule & TFQuery freed here FreeContext; //<-- TFDQuery is in the current context so attempts to free here = Invalid Pointer Operation FTeardownTime.Stop; end; I'd rather not have to create my own JSON stream, but I'd like to have my DB logic encapsulated in a data module. Thanks Stuart

Hi @Andrea Magni Ah brilliant, I wondered what "IsReference" meant 😄 Thanks again

Hi, I'm looking at the TMARSFDDataModuleResource and I see that it has protected members `FD` (TMarsFireDAC) and `URL` (TMARSURL). In my descendant class both of these are `nil` references. Is there a way to use this? Reason is I'm trying to switch DB connections based on the server's own host URL. E.g. if it's accessed via localhost or 192.168.x.x then use the LOCAL_DB connection def, otherwise use PROD_DB Edit: Which also begs the question, where is the best place to call `FD.ConnectionDefName := MyConnectionDefName;` ? Thanks Stuart

Hello Andrea, That's excellent, thank you very much for your detailed answer. I agree with you that the Connection attribute seems a much cleaner implementation and I will have a go at refactoring my project. Thanks again, Best wishes, Stuart

Ah, figured it out. FEngine.BeforeHandleRequest := function (const AEngine: TMARSEngine; const AURL: TMARSURL; const ARequest: TWebRequest; const AResponse: TWebResponse; var Handled: Boolean): Boolean var App: TMARSApplication; begin Result := True; // skip favicon requests (browser) ... [snip] // Handle CORS and PreFlight ... [snip] // Get the default connection name based on the host URL if (pos('localhost', AUrl.URL) > 0) or (pos('192.168.', aUrl.URL) > 0) then cConnectionDefname := 'LOCAL_DB' else cConnectionDefName := 'MAIN_DB'; // apply to every application for App in AEngine.Applications.Values do App.Parameters.Values['FireDAC.ConnectionDefName'] := cConnectionDefName; end; So I get the default connection def name based on the URL. Then set the correct parameter for each hosted application. (My previous mistake was setting the `FireDAC.ConnectionDefName` parameter at the Engine level) If anyone can think of a better or more elegant way, please let me know. Thanks

Thanks Lars. I'm making a lot of use of the TMARSFireDAC instance (usually called FD) that gets injected into the resource classes which is great for simple data -> api tasks. I only rarely use a separate datamodule with an FDConnection component. When I do, I can just set the FDConnection1.ConnectionDefName to whatever is in the INI file in DataModuleCreate. I can also set FD.ConnectionDefName, but the thing I'm most struggling with is where? I can't see any way to set the default connection name in BeforeHandleRequest. The RegisterBeforeInvoke has access to the Application.Parameters (where I think I can set ['FireDAC.ConnectionDefName']) but it's called after the TMARSFireDAC instance is already created and injected. 😕

Hi Andrea, Thanks very much. Confirmed working with Postman and the delphi demo client. Still can't get my HTML to work though - it just uploads the file name not the file contents. Looking into this now. *Edit* My bad forgot the enctype="multipart/form-data" attribute from the form tag (which is ironic given that I was testing multipart/form-data, ha ha) Kind regards, Stuart

Hi Andrea, I want to implement this in my server, so I started with your demo above and tried to use Postman to test the API. When I run Postman against your [..]/helloworld/2 endpoint I get the following back: { "JSONData": "{\"name\": \"Stuart\"}", "PersonName": "Stuart", "FileName": "", "FileSize": 0 } This is my PostMan Setup: https://imgur.com/td0fDJ4 (Sorry, can't find anyway to export the Postman config for that request). The json data is picked up okay, but not the file data. I'm sending an Excel file in this case, but I've tried pure binary files like JPGs too. Can you see what I'm doing wrong with Postman? Thanks

Hi, I'm trying to save a JWT token to a file between program runs. I have a console app that runs on a short schedule and I want to prevent having to authenticate each time. I am using MarsClientToken SaveToStream / LoadFromStream to get the json token data into and out of a temp file. The contents of the temp file look fine & contain the json I would expect, i.e. the "Token" and each token property (the expired date is always +24hrs ) When the token data is loaded from the file, IsVerified = True, isExpired = false, and Authenticated = True, but I am getting 403 forbidden when I make my api calls. Logging in with username/password works fine of course. Is there something I am missing ? Thanks

Thanks Andrea. Good luck with that 😉

HI Andrea, Yes, that was it, I had AuthEndorsement set to cookie. So sorry, I thought I had checked that but clearly not. Kind regards

Hi, I've tried adding a second app to my MARS rest engine (in order to support my api's version 2) as follows: class constructor TServerEngine.CreateEngine; var MyApp, MyApp2 : TMARSApplication; begin FEngine := TMARSEngine.Create; try // Engine configuration FEngine.Parameters.LoadFromIniFile; // Application configuration MyApp := FEngine.AddApplication('IBCSApp', '/ibcs', [ 'Server.Resources.*']); // Second Application (version 2 of the API) MyApp2 := FEngine.AddApplication('IBCSApp2', '/ibcs2', [ 'server2.Resources.*']); // [....] End; And I've created a server2.Resources.pas file into which I've added a simple "/healthcheck" resource that returns the server time as a string. I've also added this line initialization TMARSResourceRegistry.Instance.RegisterResource<THealthCheck>; But when the server runs, IBCSApp2 is shown in the list of engines, but it does not contain the /healthcheck resource. I should mention that the original app (IBCSApp) also has the same resource name (/healthcheck) implemented by a different class. I guess I am missing something? Thanks Stuart

Thanks Andrea -- adding the server2.resources unit to the server.ignition.pas uses clause worked. Kind regards

Hi, Does anyone know the required steps to override the JWT params defaults for SECRET and ISSUER please? I can see they seem to need to be in the Activation.Parameters... but I'm not sure how to get them in there? Thanks in advance, Stuart