Salesforce :: Can not add Visual Force page to Custom button

1. At first create a custom controller (Apex Class) with following contents:

public with sharing class CommonController {

    private ApexPages.StandardController standardController;
    
    public Account account { get; private set; }
    
    public CommonController (ApexPages.StandardController standardController) {
        this.standardController = standardController;
        Id recordId = standardController.getId();
        account = (Account) standardController.getRecord();
    }
    
    public PageReference doSomething() {
        //after some tasks return to Account details view
        return standardController.view();
    }
    
    public PageReference cancel() {
        // return to account details view
        return standardController.view();
    }
    
}

2. Create a "Visualforce Pages" page with following contents:

<apex:page standardController="Account" extensions="CommonController">
    Account_Selected=<b>{!Account.Name}</b><br/>
    <apex:form >
        <apex:commandButton value="Do something in CommonController.doSomething()" action="{!doSomething}"/>
        <apex:commandButton value="Cancel this process & return to details view" action="{!cancel}"/>
    </apex:form>
</apex:page>

3. Go to "setup/Customize/Accounts/Buttons, Links, and Actions" and click on "New button or link"
4. Select "Display Type" as "Detail Page Button"
5. Select "Behavior" as "Display in existing window without sidebar or header"
6. Select "Content Source" as "Visualforce Page"
7. And finally select a controller created before from "Content" dropdown.
8. Now go to "setup/Customize/Accounts/Page Layouts"
9. Edit any of your layout you used to test this case
10. Select "Buttons" panel and drop the button created before in details panel
11. Now go to your account details page and now you can see the button available.

Salesforce create custom controller

1. Go to "setup/Develop/Apex Classes" and click "new"
2. Write the following code:

public class CustomController {

    public Account account { get; private set; }

    public NewAndExistingController() {
        Id id = ApexPages.currentPage().getParameters().get('id');
        account = (id == null) ? new Account() :
            [SELECT Name, Phone, Industry FROM Account WHERE Id = :id];
    }

    public PageReference save() {
        try {
            upsert(account);
        } 
        catch(System.DMLException e) {
            ApexPages.addMessages(e);
            return null;
        }
        //  After successful Save, navigate to the default view page
        PageReference r = new ApexPages.StandardController(Account).view();
        return (r);
    }
}

3. Go to "setup/Develop/Visualforce Pages" and click "new"
4. Write the following code:

<apex:page controller="CustomController" tabstyle="Account">
    <apex:form>
        <apex:pageBlock mode="edit">
            <apex:pageMessages/>
            <apex:pageBlockSection>
                <apex:inputField value="{!Account.name}"/>
                <apex:inputField value="{!Account.phone}"/>
                <apex:inputField value="{!Account.industry}"/>
            </apex:pageBlockSection>
            <apex:pageBlockButtons location="bottom">
                <apex:commandButton value="Save" action="{!save}"/>
            </apex:pageBlockButtons>
        </apex:pageBlock>
    </apex:form>
</apex:page>

5. Go to "setup/Create/Tabs" click on "new" under group "Visualforce Tabs"
6. Select "Visualforce Page" created before & provide other information & save.

7. Browse your custom tab to access the custom tab.

Show HTML string as an HTML output instead of plain text in Salesforce Visaul Force page

Write the following code snippet:

<apex:outputLabel escape="false" Value="{!html}" ></apex:outputLabel>

Instead of the following:

{!html} 

How to make a post or get request to some other server from apex class

1. Go to "setup/Develop/Apex Class"
2. Click "new"
3. Write code as following:

public class ApexClass_1 {
    @Future(callout=true)
    public static void c1(String Account_ID) {
        String name = '';
        try {
            HttpRequest req = new HttpRequest();
            req.setEndpoint('http://www.yahoo.com');
            req.setMethod('POST');
            req.setBody('Account_ID='+EncodingUtil.urlEncode(Account_ID, 'UTF-8')+'&other_param='+EncodingUtil.urlEncode('OTHER PARAM VALUE', 'UTF-8'));
            req.setCompressed(true);

            /* If you want to send basic authentication */
            String username = 'myname';
            String password = 'mypwd';
            Blob headerValue = Blob.valueOf(username + ':' + password);
            String authorizationHeader = 'BASIC ' + EncodingUtil.base64Encode(headerValue);
            req.setHeader('Authorization', authorizationHeader);

            Http http = new Http();
            HTTPResponse res = http.send(req);
            name = 'Status_Code=' + res.getStatusCode();
            String responseBody = res.getBody();
        }
        catch(System.CalloutException e) {
            System.debug('Callout error: '+ e);
            name = ('Error=' + e.getMessage()).substring(0, 20);
        }

        /* Reading account object */
        Account account = [SELECT Id FROM Account WHERE Id = :Account_ID];
        account.Name = name;
        update op;
    }
}

4. Go to "setup/Security Controls/Remote Site Settings"
5. Click "New remote site" & enter the URL that you want to invoke from apex class.
6. Invoke method "ApexClass_1.c1" from wherever you want.

7. An example of invoke url in salesforce from apex sObjects trigger options
8. Go to "setup/Customize/Accounts/Triggers"
9. Click "new"
10. Write the following code:

trigger TriggerActionName on Account (before insert, after insert, after delete) {
    if (Trigger.isInsert) {
        if (Trigger.isAfter) {
            for (Account a : Trigger.New) {
                ApexClass_1.c1(a.Id);
            }
        }
    }
}

11. Once you create a new account the url would be invoked in a short time (Also you could write code for update & delete)
12. Apex trigger documentation: https://developer.salesforce.com/trailhead/en/apex_triggers/apex_triggers_intro

Java Convert File Into Bytes (Array of Bytes)

package com.pritom.kumar;

import java.io.File;
import java.io.FileInputStream;

/**
 * Created by pritom on 28/06/2016.
 */
public class ReadFileAsByteArray {
    public static void main (String[] args) throws Exception {
        File file = new File("x1.zip");

        FileInputStream fileInputStream = new FileInputStream(file);
        byte[] toByte = new byte[(int) file.length()];
        fileInputStream.read(toByte);
        fileInputStream.close();

        System.out.println("File_Length=" + file.length() + ", Byte_Length=" + toByte.length + ", Both_Are_Equal=" + (file.length() == toByte.length ? "True" : "False"));
    }
}

Output:

File_Length=14805774, Byte_Length=14805774, Both_Are_Equal=True

Java code to compress & decompress of string using deflater & inflater

Code snippet for compress & decompress of string...

package com.pritom.kumar;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import java.io.ByteArrayOutputStream;
import java.util.zip.Deflater;
import java.util.zip.Inflater;

/**
 * Created by pritom on 27/06/2016.
 */
public class CompressString {
    public static final String encoding = "UTF-8";

    public static void main (String[] args) throws Exception {
        String s = "123456789 a s d f g h j k l ; ' q w e r t y u i o p [ ] \\ 1 2 3 4 5 6 7 8 9 0 - = as df gh jk l; zx cv bn m, ./ qw y ui op []" +
                "qwe rty uio p[] asd fgh jkl zxc vbn m,. 123 456 789 1234 5678 90-= qwer tyui op[] asdf ghjk l;zx cvbn m,./" +
                "12345 67890 qwert yuiop asdfg hjklz xcvbn m,khg er xcgvdst 453 gd fyrt634 5 dg e653 545u7r ydf dgfsd fsart sdgdsg" +
                "sd fsdjf;sjduw[r sldfjsl;djrf2345203v sdfs'wse[rftu 2[3r50 j;lgjks'drf 2354-0u sadfas';dfmka][ ert02u9wsd's;lad fa'sdfjasdgf" +
                "4 wr[w09u jsd' af32 'QWRJE ajfsdj :ejwkiiuUUSJ W[9230 U'SFJKS JFJSF 'ASDP;GF SDFAW435]2 JKSD';GDALSJ GF'SDAGJFMA'L 2UWQ 'PS;DGJM" +
                "ju=[0a9 u0wr w435r]2345ru]2tu  s'adgjfa'sgf2uq]34u]23'g jfq4323o4 23w 52]5-2t4ewsjtrg'qwpe[fa7 2   03r/ dshgf" +
                "djl3r4 sjdf ;wq3r q3ra[d0aw'tj3 wr[w09u asd fgh zxc er gd swser9[0345r]2 3dfjsdfsd ]23-qg';gvas 'dgawejrt ]23trwasdg;mas'fgsnkd gasf " +
                "[w90rtusdmgkf zxc sadfs fa fsart sdgdsg wr JFJSF GF fgh xcgvdst dfmka SDAGJFMA 2345ru wse[rftu 2[3r50 j;l af32 sdfjasdgf jks'drf 2354-" +
                "djrf2345203v KSD';GDALSJ GF'";

        String compressed = compress(s);
        Integer savedLength = s.length() - compressed.length();
        Double saveRatio = (new Double(savedLength) * 100) / s.length();
        String ratioString = saveRatio.toString() + "00000000";
        ratioString = ratioString.substring(0, ratioString.indexOf(".") + 4);
        println("Original_String_Length=" + s.length());
        println("Compressed_String_Length=" + compressed.length() + ", Compression_Ratio=" + ratioString + "%");

        String decompressed = decompress(decodeBase64(compressed));
        println("Decompressed_String_Length=" + decompressed.length() + " == Original_String_Length (" + s.length() + ")");
        println("Original_String == Decompressed_String=" + (s.equals(decompressed) ? "True" : "False"));
    }

    public static String compress(String str) throws Exception {
        return compress(str.getBytes(encoding));
    }

    public static String compress(byte[] bytes) throws Exception {
        Deflater deflater = new Deflater();
        deflater.setInput(bytes);
        deflater.finish();
        ByteArrayOutputStream bos = new ByteArrayOutputStream(bytes.length);
        byte[] buffer = new byte[1024];
        while(!deflater.finished()) {
            int count = deflater.deflate(buffer);
            bos.write(buffer, 0, count);
        }
        bos.close();
        byte[] output = bos.toByteArray();
        return encodeBase64(output);
    }

    public static String decompress(byte[] bytes) throws Exception {
        Inflater inflater = new Inflater();
        inflater.setInput(bytes);
        ByteArrayOutputStream bos = new ByteArrayOutputStream(bytes.length);
        byte[] buffer = new byte[1024];
        while (!inflater.finished()) {
            int count = inflater.inflate(buffer);
            bos.write(buffer, 0, count);
        }
        bos.close();
        byte[] output = bos.toByteArray();
        return new String(output);
    }

    public static String encodeBase64(byte[] bytes) throws Exception {
        BASE64Encoder base64Encoder = new BASE64Encoder();
        return base64Encoder.encodeBuffer(bytes).replace("\r\n", "").replace("\n", "");
    }

    public static byte[] decodeBase64(String str) throws Exception {
        BASE64Decoder base64Decoder = new BASE64Decoder();
        return base64Decoder.decodeBuffer(str);
    }

    public static void println(Object o) {
        System.out.println("" + o);
    }
}

Output would be like this...

Original_String_Length=1000
Compressed_String_Length=824, Compression_Ratio=17.600%
Decompressed_String_Length=1000 == Original_String_Length (1000)
Original_String == Decompressed_String=True

** More big string more compression ratio
** More similar words more compression ratio

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