Groovy call a closure with parameters

Closure closureTest = { def args1 = null, def args2 = null ->
    /* do something you wish */
}

/* Call above closure as like: */
closureTest.call() /* It will pass args1 & args2 both null */
closureTest("value_args1") /* It will pass args2 null */
closureTest(null, "value_args2") /* It will pass args1 null */
closureTest("value_args1", "value_args2") /* It will pass both args1 & args2 value */

/* You can check number of parameters accept by a closure as like: */
closureTest.maximumNumberOfParameters

Grails track hibernate transaction begin, flush, commit and rollback status

Package: org.springframework.orm.hibernate4

Class: HibernateTransactionManager

Hibernate evict an persistent object from hibernate session

package com.pkm.evict_entity

import grails.util.Holders
import org.hibernate.SessionFactory

/**
 * Created by pritom on 3/08/2016.
 */
class EvictEntityInstance {
    public static void _evict(def domainInstance) {
        getBean(SessionFactory).currentSession.evict(domainInstance)
    }

    public static <T> T getBean(Class<T> requiredType) {
        try {
            return Holders.applicationContext.getBean(requiredType)
        }
        catch (Exception e) {
            return null
        }
    }
}

Salesforce PDF Viewer with custom PDF page

1. First create a apex class with following contents:

global with sharing class QuoteCustomPdfGenerator {
    private ApexPages.StandardController sc;
    public Quote q {get; private set;}
    public String id {get; private set;}

    public QuoteCustomPdfGenerator(ApexPages.StandardController controller) {
        this.sc = sc;
        this.id = ApexPages.currentPage().getParameters().get('Id');
        this.q = [SELECT Id,Name From Quote WHERE Id=:this.id];
    }
    
    public PageReference viewPdf() {
        return null;
    }

    webService static String createQuotePdf(String Id) {
        try {
            PageReference pageRef = new PageReference('/apex/QuoteCustomPdfView?Id='+Id);
            Blob content = pageRef.getContent();
            QuoteDocument doc = new QuoteDocument(Document = content, QuoteId = Id);
            insert doc;

            return 'SUCCESS';
        } 
        catch(exception ex) {
           System.debug('--- Error ----------'+ ex);
           return ex.getMessage();
        }
    }
}

2. Now create a visualforce page with following contents (Name of visualforce page="QuoteCustomPdfView"):

<apex:page standardController="Quote" extensions="QuoteCustomPdfGenerator" action="{!viewPdf}" renderAs="pdf">
    This is my custom pdf for the quote=[[{!q.Name}]]
</apex:page>

3. Create a local js file with following contents:

function SaveQuoteAsCustomPDF(quoteId) {
    try {
        var res = sforce.apex.execute("QuoteCustomPdfGenerator","createQuotePdf",{Id : quoteId});
        if(res=='SUCCESS') {
            window.location.reload();
        }
        else {
            alert('Error in attaching file ----'+ res);
        }
    }
    catch(er) {
        alert(er);
    }
}

4. Upload the js file in static resource section with name = "SaveQuoteAsCustomPDF".
5. After upload done click on view and copy the url from browser.
6. Now create a custom button under Quote section in setup with following configurations
6.1: "Display Type" = "Detail Page"
6.2: "Behavior" = "Execute JavaScript"
6.3: "Content Source" = "OnClick JavaScript"
6.4: Put the following contents in the box below:

{!REQUIRESCRIPT("/soap/ajax/24.0/connection.js")}
{!REQUIRESCRIPT("/soap/ajax/24.0/apex.js")}
{!REQUIRESCRIPT("/resource/1470022474000/SaveQuoteAsCustomPDF")} /* Location from step 5 */

var pdfOverlay = QuotePDFPreview.quotePDFObjs['quotePDFOverlay'];
pdfOverlay.dialog.buttonContents = '<input value=\"Save Quote As PDF\"  class=\"btn\" name=\"save\" onclick=\"SaveQuoteAsCustomPDF(\'{!Quote.Id}\');\" title=\"Save Quote As PDF\" type=\"button\" /><input value=\"Close\"  class=\"btn\" name=\"cancel\" onclick=\"QuotePDFPreview.getQuotePDFObject(\'quotePDFOverlay\').close();\" title=\"Close\" type=\"button\" />';

pdfOverlay.setSavable(true);
pdfOverlay.setPDFContents('/apex/QuoteCustomPdfView?Id={!Quote.Id}',null,null);
pdfOverlay.display();

7. Add the button in quote page layout.
8. View details of a quote & click the button you added on step 7.

Salesforce : DML currently not allowed

If you write create/update/delete operation in apex controller constructor then this error would be thrown.
You have to do some trick to get rid of this problem.
First create an action with your create/update/delete operations in your controller.
And then add the action name in your apex:page as attribute which will call with constructor.

<apex:page standardController="Account" extensions="APEX_CONTROLLER_CLASS_NAME" action="{!YOUR_ACTION_NAME}">
DO YOUR OTHER WORKS HERE...
</apex:page>

Parse JSON in Salesforce

public class CommonJsonParser {
    public cls_Parent[] parentList;
    class cls_Parent {
        public Integer intType;
        public Double doubleType;
        public String stringType;
        public cls_Child[] childList;
    }
    class cls_Child {
        public Integer param_1;
        public String param_2;
    }
    public static CommonJsonParser parse(String json){
        return (CommonJsonParser) System.JSON.deserialize(json, CommonJsonParser.class);
    }

    public static String test() {
        String json = '{"parentList":[' + 
            '{"intType":1,"doubleType":1.5,"stringType":"String_1",' + 
            '"childList":[' + 
                '{"param_1":1,"param_2":"String_100"},' + 
                '{"param_1":5,"param_2":"String_101"}]}'+
            ',{"intType":2,"doubleType":2.5,"stringType":"String_2",' + 
            '"childList":[' + 
                '{"param_1":6,"param_2":"String_102"},' + 
                '{"param_1":2,"param_2":"String_103"},' + 
                '{"param_1":1,"param_2":"String_104"}]}]}';
        CommonJsonParser obj = parse(json);
        
        String output = '';
        
        for(cls_Parent cParent : obj.parentList) {
            output += '<br/>';
            output += '[[ Integer_Value=' + cParent.intType;
            output += ', Double_Value=' + cParent.doubleType;
            output += ', String_Value=' + cParent.stringType + ' ]]';
            
            for(cls_Child cChild: cParent.childList) {
                output += '<br/>&nbsp;&nbsp;&nbsp;&nbsp;Param_1=' + cChild.param_1;
                output += ', Param_2=' + cChild.param_2;
            }
        }
        
        return output;
    }
}

Output would be like this:

[[ Integer_Value=1, Double_Value=1.5, String_Value=String_1 ]]
    Param_1=1, Param_2=String_100
    Param_1=5, Param_2=String_101
[[ Integer_Value=2, Double_Value=2.5, String_Value=String_2 ]]
    Param_1=6, Param_2=String_102
    Param_1=2, Param_2=String_103
    Param_1=1, Param_2=String_104 

Git: comparing remote branches, different between two remote branches

git diff --name-status origin/master...remotes/origin/2.0.0

git diff master remotes/origin/2.0.0 -- app/../File.name