Raw template logging implementation

[randilt]

Purpose

Resolves: #3331

Examples

public function main() {
    string myname = "Alex92";
    int myage = 25;
    string action1 = "action1";
    string action2 = "action2";
    string action3 = "action3";
    log:printError(`error: My name is ${myname} and my age is ${myage}`);
    log:printWarn(`warning: My name is ${myname} and my age is ${myage}`);
    log:printInfo(`info: My name is ${myname} and my age is ${myage}`);
    log:printDebug(`debug: My name is ${myname} and my age is ${myage}`);
    log:printInfo("User details", details = `name: ${myname}, age: ${myage}`, actions = `actions: ${action1}, ${action2}, ${action3}`);   
}

Checklist

• Linked to an issue
• Updated the changelog
• Added tests
• Updated the spec
• Checked native-image compatibility

[randilt]

I added the suggested changes, but I have an issue, why is the build failing in the workflow? all the testcases pass when I run it locally @daneshk
2 testcases are failing in the workflow, I didn't change them or anything related to them.

[daneshk]

I added the suggested changes, but I have an issue, why is the build failing in the workflow? all the testcases pass when I run it locally @daneshk

2 testcases are failing in the workflow, I didn't change them or anything related to them.

Let me check

[TharmiganK]

I added the suggested changes, but I have an issue, why is the build failing in the workflow? all the testcases pass when I run it locally @daneshk 2 testcases are failing in the workflow, I didn't change them or anything related to them.

Only the GraalVM build workflows are failing and these workflows runs with the ballerina-lang master. Some changes done to the ballerina-lang master is causing these failures. We can disable the GraalVM checks since your changes does not affect the GraalVM compatibility.

[randilt]

I added the suggested changes, but I have an issue, why is the build failing in the workflow? all the testcases pass when I run it locally @daneshk 2 testcases are failing in the workflow, I didn't change them or anything related to them.

Only the GraalVM build workflows are failing and these workflows runs with the ballerina-lang master. Some changes done to the ballerina-lang master is causing these failures. We can disable the GraalVM checks since your changes does not affect the GraalVM compatibility.

Thanks for the clarification :)

[TharmiganK]

@randilt I would like to add some insights on the issue since the implementation in the io package is out-dated.

The objective is to add raw template support in the log functions. The raw template and string template are different.

1. Raw template - https://ballerina.io/learn/by-example/raw-templates/

   `Hello, ${name}`
   

2. String template or Backtick template - https://ballerina.io/learn/by-example/backtick-templates/

   string `Hello, ${name}`
   

In the log package we already support string templates. The following is working with the existing log package:

import ballerina/log;

public function main() {
   string myname = "Alex92";
   int myage = 25;
   log:printError(string `error: My name is ${myname} and my age is ${myage}`);
   log:printWarn(string `warning: My name is ${myname} and my age is ${myage}`);
   log:printInfo(string `info: My name is ${myname} and my age is ${myage}`);
   log:printDebug(string `debug: My name is ${myname} and my age is ${myage}`);
   log:printInfo("User details", details = string `name: ${myname}, age: ${myage}`);   
}

What we want from this new feature is to support the following:

import ballerina/log;

public function main() {
  string myname = "Alex92";
  int myage = 25;
  log:printError(`error: My name is ${myname} and my age is ${myage}`);
  log:printWarn(`warning: My name is ${myname} and my age is ${myage}`);
  log:printInfo(`info: My name is ${myname} and my age is ${myage}`);
  log:printDebug(`debug: My name is ${myname} and my age is ${myage}`);
  log:printInfo("User details", details = `name: ${myname}, age: ${myage}`);   
}

In order to do that you need to add a raw template type to the currently supported parameter type - Value:

public type Value anydata|Valuer|PrintableRawTemplate;

Please note that the PrintableRawTemplate should be a subtype of object:RawTemplate(Please refer to the Ballerina By Example)

public type PrintableRawTemplate object {
   *object:RawTemplate;
   // Since the `object:RawTemplate` already support `string[] & readonly` as the type for `strings`
   // we do not need to change it
   
   // The default `insertions` are with type `any|error[]` but we only need to support the values
   // We are currently supporting `Value`. You can also just support `anydata|Valuer` for now
   public Value[] insertions;
};

Now, we have allowed raw templates in the log function parameters, now we need to implement the string conversion. Now we do not need this class - PrintableRawTemplateImpl, we can directly check the type and implement a function to convert it to a string. (i.e. separate the toString function of this class as a separate function)

I hope you understand the issue now :)

[randilt]

@randilt I would like to add some insights on the issue since the implementation in the io package is out-dated.

The objective is to add raw template support in the log functions. The raw template and string template are different.

1. Raw template - https://ballerina.io/learn/by-example/raw-templates/

   `Hello, ${name}`
   

2. String template or Backtick template - https://ballerina.io/learn/by-example/backtick-templates/

   string `Hello, ${name}`
   

In the log package we already support string templates. The following is working with the existing log package:

import ballerina/log;

public function main() {
   string myname = "Alex92";
   int myage = 25;
   log:printError(string `error: My name is ${myname} and my age is ${myage}`);
   log:printWarn(string `warning: My name is ${myname} and my age is ${myage}`);
   log:printInfo(string `info: My name is ${myname} and my age is ${myage}`);
   log:printDebug(string `debug: My name is ${myname} and my age is ${myage}`);
   log:printInfo("User details", details = string `name: ${myname}, age: ${myage}`);   
}

What we want from this new feature is to support the following:

import ballerina/log;

public function main() {
  string myname = "Alex92";
  int myage = 25;
  log:printError(`error: My name is ${myname} and my age is ${myage}`);
  log:printWarn(`warning: My name is ${myname} and my age is ${myage}`);
  log:printInfo(`info: My name is ${myname} and my age is ${myage}`);
  log:printDebug(`debug: My name is ${myname} and my age is ${myage}`);
  log:printInfo("User details", details = `name: ${myname}, age: ${myage}`);   
}

In order to do that you need to add a raw template type to the currently supported parameter type - Value:

public type Value anydata|Valuer|PrintableRawTemplate;

Please note that the PrintableRawTemplate should be a subtype of object:RawTemplate(Please refer to the Ballerina By Example)

public type PrintableRawTemplate object {
   *object:RawTemplate;
   // Since the `object:RawTemplate` already support `string[] & readonly` as the type for `strings`
   // we do not need to change it
   
   // The default `insertions` are with type `any|error[]` but we only need to support the values
   // We are currently supporting `Value`. You can also just support `anydata|Valuer` for now
   public Value[] insertions;
};

Now, we have allowed raw templates in the log function parameters, now we need to implement the string conversion. Now we do not need this class - PrintableRawTemplateImpl, we can directly check the type and implement a function to convert it to a string. (i.e. separate the toString function of this class as a separate function)

I hope you understand the issue now :)

Wow, thanks a lot for the clarification, I just overcomplicated it :D, I will do the necessary changes and update the PR,
Thanks again!

[randilt]

Please note that the PrintableRawTemplate should be a subtype of object:RawTemplate(Please refer to the Ballerina By Example)

public type PrintableRawTemplate object {
   *object:RawTemplate;
   // Since the `object:RawTemplate` already support `string[] & readonly` as the type for `strings`
   // we do not need to change it
   
   // The default `insertions` are with type `any|error[]` but we only need to support the values
   // We are currently supporting `Value`. You can also just support `anydata|Valuer` for now
   public Value[] insertions;
};

If I do not redeclare the strings and insertions in here the testcases are failing, if I keep it as it is it will work as expected.

public type PrintableRawTemplate object {
    *object:RawTemplate;
    public string[] & readonly strings;
    public Value[] insertions;
};

So for now can I keep it as this?
@TharmiganK

[TharmiganK]

If I do not redeclare the strings and insertions in here the testcases are failing, if I keep it as it is it will work as expected.

public type PrintableRawTemplate object {
    *object:RawTemplate;
    public string[] & readonly strings;
    public Value[] insertions;
};

So for now can I keep it as this?

Yes, sure, but ideally this should work:

public type PrintableRawTemplate object {
     *object:RawTemplate;
     public Value[] insertions;
};

Can you share the error you get?

[randilt]

It is a runtime error:

error: java.lang.ClassCastException: class java.lang.Long cannot be cast to class io.ballerina.runtime.api.values.BString (java.lang.Long is in module java.base of loader 'bootstrap'; io.ballerina.runtime.api.values.BString is in unnamed module of loader 'app')
        at ballerina.log.2:processTemplate(natives.bal:111)
           ballerina.log.2:processMessage(natives.bal:117)
           ballerina.log.2:print(natives.bal:211)
           ballerina.log.2:printError(natives.bal:147)
           main:main(main.bal:25)


        testErrorLevelRawTemplateLogfmt: has failed.

Only the 5 newly added testcases are failing (raw template testcases), but if I override strings field and insertions field both
it works without an issue
Not sure why this is happening, therefore I will keep it as it is for now
@TharmiganK

[TharmiganK]

+1, it seems to be a lang issue. I will check on that. Meanwhile lets keep it as it is

Related lang issue: ballerina-platform/ballerina-lang#43501

[randilt]

I have made the changes you requested, could you please check? @TharmiganK

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[TharmiganK]

LGTM
@randilt Thank you for your valuable contribution 🎉