Get and post request to URL

[torbente]

I need interact with a rest api server. I found it is easy to send get request with fphttpclient:

Code: Pascal  [Select][+][-]

1. function ReadURLGet(url:string):string;
2. begin
3. with TFPHTTPClient.Create(nil) do
4. try
5.   ReadURL:= Get(url);
6. finally
7.   Free;
8. end;
9.  
10. end;  

Since server answer is always a Json format string, it works perfect for me. But how about post request? Is there any simple way with fphttpclient? Something like:

Code: Pascal  [Select][+][-]

1. function ReadURLPost(url:string;data:array):string;
2. begin
3. with TFPHTTPClient.Create(nil) do
4. try
5.   ReadURL:= Post(url,data);
6. finally
7.   Free;
8. end;
9.  
10. end;

Any simple code for "example.com", using user:jhondoe and pass:9999 as post data?

[balazsszekely]

The easiest way is:

Code: Pascal  [Select][+][-]

1.   with TFPHTTPClient.Create(nil) do
2.   try
3.      SimplePost(); // or Post();
4.   finally
5.     Free;
6.   end;

[torbente]

The easiest way is:

Code: Pascal  [Select][+][-]

1.   with TFPHTTPClient.Create(nil) do
2.   try
3.      SimplePost(); // or Post();
4.   finally
5.     Free;
6.   end;

And the data?

[balazsszekely]

@torbente

Just take a look at the declaration of Post/SimplePost:

Code: Pascal  [Select][+][-]

1.    Procedure Post(const URL: string; const Response: TStream);
2.    Procedure Post(const URL: string; Response : TStrings);
3.    Procedure Post(const URL: string; const LocalFileName: String);
4.    function Post(const URL: string) : String;
5.  
6.    Class Procedure SimplePost(const URL: string; const Response: TStream);
7.    Class Procedure SimplePost(const URL: string; Response : TStrings);
8.    Class Procedure SimplePost(const URL: string; const LocalFileName: String);
9.    Class function SimplePost(const URL: string) : String;
10.  

Now you can decide which method do you want to use. Also take a look at this: http://forum.lazarus.freepascal.org/index.php/topic,39638.msg272761.html#msg272761

[torbente]

http://forum.lazarus.freepascal.org/index.php/topic,39638.msg272761.html#msg272761

That example was enough. Thanks again.

EDIT: Upps! The url is HTTPS and now i get a "invalid protocol:HTTPS" error. Any workaround?

[Leledumbo]

http://forum.lazarus.freepascal.org/index.php/topic,39638.msg272761.html#msg272761

That example was enough. Thanks again.

EDIT: Upps! The url is HTTPS and now i get a "invalid protocol:HTTPS" error. Any workaround?

Install OpenSSL, the unit should automatically register HTTPS protocol when it finds the library.

[torbente]

It worked!

I installed the open ssl in my PC but i still get the same error.
What i did:

- I copy the openssl .dll files in my windows/system and in my app root directory.
- i added the unit openssl.

What else i need do?

[Leledumbo]

- I copy the openssl .dll files in my windows/system and in my app root directory.

Make sure the files are named as written in the interface var section here: https://svn.freepascal.org/svn/fpc/tags/release_3_0_4/packages/openssl/src/openssl.pas

- i added the unit openssl.

Not needed.

[torbente]

libeay32.dll and ssleay32.dll are in many places: windows/system, windows/system32, my app root directory and even in the lazarus directory. Still not working. 

[balazsszekely]

@torbente
libeay32.dll and ssleay32.dll are in many places: windows/system, windows/system32, my app root directory and even in the lazarus directory. Still not working. 

Then you most likely use a wrong version of the dlls. Download from here:
   32bit: http://packages.lazarus-ide.org/openssl-1.0.2j-i386-win32.zip
   64bit: http://packages.lazarus-ide.org/openssl-1.0.2j-x64_86-win64.zip

[torbente]

@torbente
libeay32.dll and ssleay32.dll are in many places: windows/system, windows/system32, my app root directory and even in the lazarus directory. Still not working. 

Then you most likely use a wrong version of the dlls. Download from here:
   32bit: http://packages.lazarus-ide.org/openssl-1.0.2j-i386-win32.zip
   64bit: http://packages.lazarus-ide.org/openssl-1.0.2j-x64_86-win64.zip

Those were the same files i was using. Anyway, i re-download your files with the same result. I even try with 64 bits even when my PC is a 32 bits system but nothing.

Im using Windows 7 Home Basic, 32 Bits, Running LLazarus V 1.44

So maybe is something with the code?

Code: Pascal  [Select][+][-]

1. function ReadURL(url:string):string;
2. begin
3. with TFPHTTPClient.Create(nil) do
4. try
5.   ReadURL:= Get('https://api.bitfinex.com/v1/ticker/btcusd');
6. finally
7.   Free;
8. end;
9. end;

Im getting a "Invalid Protocol:https" error.

EDIT: I noticed that sometimes the icon of the lazarus IDE is pink and sometimes yellow. Any reason for this?

[balazsszekely]

Im using Windows 7 Home Basic, 32 Bits, Running LLazarus V 1.44

You should update to Lazarus 1.8/FPC 3.04. Any good reason to stay with 1.4?

So maybe is something with the code?

It's nothing wrong with that code, fphttpclient works great. I use it extensively in my applications, Lazarus IDE also use it. Take a look at the attached screenshot.

[torbente]

Well, i did not use lazarus for +2 yeras and i really did not believe update lazarus necessary 
Any easy way to update it? Im checking the lazarus IDE for an auto-update, and the directory for a file but nothing. I searched the web and look like the best way is manual.
I will update lazarus and the try again.

[balazsszekely]

Since you're on windows it's very easy. Just uninstall the old version, then install the new one with the installer. Make sure you delete the old config files.

[Thaddy]

Best to use the official repositories  or fpcupdeluxe to upgrade.