Pls explain this

Hi
response.setHeader("Expires","-1");
response.setHeader("Cache-Control","no-store,
no-cache");
response.setHeader("Pragma","no-cache");So many times i heard about the above lines.
But I cannot understand the meaning of these lines
correctly.
Can anybody pls explian me about these?
Thank you so muchin the above code
response.setHeader("Cache-Control","no-store, no-cache");
-- > Forces caches to obtain a new copy of the page from the origin server, Directs caches not to store the page under any circumstance
response.setHeader("Pragma","no-cache") --> HTTP 1.0 backward compatibility
This is generally blocks the local machine/proxy server to cache the file for redisplay if requested,
This makes every request to go to the server and get the response to avoid the cache page displayed...

Similar Messages

Pls explain this behaviour

Hi,
I have query as:
select service_request_id, sum(amount) over (partition by service_request_id order by service_request_id) from sop_travel_living
where service_request_id = '102399'
SQL> select service_request_id, sum(amount) over (partition by service_request_id order by service_request_id) Amt from sop_travel_living
2 where service_request_id = '102399';
SERVICE_REQUEST_ID Amt
102399 401
102399 401
Now actual data for that request is as under:
SQL> select service_request_id, amount from sop_travel_living
2 where service_request_id = '102399';
SERVICE_REQUEST_ID AMOUNT
102399 250.5
102399 150.5
why its returning two rows in the first query.. i need to just sum the amount be each request..
I do not want to Group By as its my requirment..
Thx

Hi Eric,
here is the big query:
SELECT DISTINCT A.SERVICE_REQUEST_ID serviceRequestId,
 TO_CHAR(TO_DATE('&endDate', 'mm/dd/yyyy'), 'mm/dd/yyyy') documentDate,
 'SA' documentType,
 E.COMPANY_CODE companyCode,
 TO_CHAR(TO_DATE('&endDate', 'mm/dd/yyyy') - 15, 'mm/dd/yyyy') postingDate,
 TO_CHAR(TO_DATE('&startDate', 'mm/dd/yyyy'), 'FMMM') fiscalPeriod,
 E.CURRENCY currencyRate,
 'JEO3094' referenceDocument,
 'FSN LIQUIDATION' headerText,
 '40' postKey,
 E.GL_ACCOUNT_JOB_DEBIT accountNumber,
 SUM(h.amount) over(PARTITION BY h.service_request_id ORDER BY h.service_request_id) Amount,
 E.TAX_CODE taxCode,
 E.TAX_JURIS_CODE taxJdcCode,
 'BDWT' businessArea,
 DECODE(A.WBS_ELEMENT, NULL,E.PROFIT_CENTER_DEBIT,E.PROFIT_CENTER_CREDIT) profitCenter,
 DECODE(A.WBS_ELEMENT, NULL, 'BETZ DEARBORN', NULL) businessCenter,
 NULL productNumber,
 DECODE(A.WBS_ELEMENT, NULL, B.SOLD_TO_CUST_ID, NULL) customerNumber,
 DECODE(A.WBS_ELEMENT, NULL, B.SALES_ORG_ID, NULL) salesOrg,
 'BD' distChannel,
 DECODE(A.WBS_ELEMENT, NULL, B.INTERCO_ID, NULL) intercoThirdParty,
 DECODE(A.WBS_ELEMENT, NULL, B.DOM_EXP_ID, NULL) domesticExport,
 DECODE(A.WBS_ELEMENT, NULL, '400', NULL) endUserCountry,
 DECODE(A.WBS_ELEMENT, NULL, B.PARTNER_ID, NULL) shipToParty,
 DECODE(A.WBS_ELEMENT, NULL, 'RESL', NULL) productionResale,
 NULL pacSegment,
 NULL pacCode,
 DECODE(A.WBS_ELEMENT, NULL, B.TERRITORY_ID, NULL) salesEmployee,
 DECODE(A.WBS_ELEMENT, NULL, A.ORDER_ID, NULL) contractNumber,
 NULL productName,
 --A.WBS_ELEMENT wbsElement,
 trim(substr(A.WBS_ELEMENT,1,instr(A.WBS_ELEMENT,'-') -1)) wbsElement,
 trim(TO_CHAR(TO_DATE('&endDate', 'mm/dd/yyyy') - 15, 'Month')) ||' FSN LIQUIDATION' longText,
 NULL orderNumber,
 NULL costCenter,
 NULL salesOrderNumber,
 NULL itemNumberInSalesOrder,
 '117965' materialNumber,
 E.PLANT plant,
 NULL purchasingDocumentNumber
 FROM SOP_SERVICE_REQUEST A,
 DMN_SALES_PARTNER B,
 SOP_COMPANY_LOOKUP_VOUCHERING E,
 SOP_DMN_WBS_ELMT F,
 sop_travel_living h,
 SELECT service_request_id,amt FROM
 SELECT service_request_id,
 row_number() over (PARTITION BY service_Request_id ORDER BY service_request_id) rn,
 SUM(amount) over (PARTITION BY service_request_id ORDER BY service_request_id) amt
 FROM sop_travel_living
 WHERE rn=1
 ) i,
/* (SELECT (SUM(LABOR_STOP - LABOR_START) * 24 +
 SUM(TRAVEL_STOP - TRAVEL_START) * 24) TOTAL_LABOR_HRS,
 srt.SERVICE_REQUEST_ID,
 ssr.FIELD_SERVICE_REP FIELD_SERVICE_REP
 FROM SOP_REPORT_TIMESHEET srt, sop_service_report ssr
 WHERE ssr.service_request_id = srt.service_request_id AND
 ssr.report_id = srt.report_id AND
 ssr.report_status <> 'REJECTED'
 GROUP BY srt.SERVICE_REQUEST_ID, FIELD_SERVICE_REP) D ,
 SELECT service_request_id,travel_start FROM
 SELECT service_request_id, row_number() over (PARTITION BY service_Request_id ORDER BY service_request_id) rn,
 travel_start
 FROM sop_report_timesheet
 --WHERE rn=1
 ) g
WHERE WORKFLOW_STATUS IN('ASSIGNED','PARTIAL ASSIGNMENT','PENDING REVIEW','CLOSED')
 AND TRUNC(g.travel_start) BETWEEN
 TO_DATE('&startDate', 'mm/dd/yyyy') AND
 TO_DATE('&endDate', 'mm/dd/yyyy')
 AND i.SERVICE_REQUEST_ID(+) = A.SERVICE_REQUEST_ID
 AND i.SERVICE_REQUEST_ID = g.SERVICE_REQUEST_ID
 AND g.service_request_id(+) = a.service_request_id
 AND h.service_request_id = a.service_request_id(+)
 AND B.DOM_EXP_ID = 'DOM'
 AND B.PARTNER_ID = A.COST_SHIP_TO_CUST_ID
 AND A.SALES_ORG_ID = B.SALES_ORG_ID
 AND E.COMPANY_CODE = B.COMPANY_ID
 AND A.WBS_ELEMENT = F.WBS_ELEMENT(+)
 AND E.COMPANY_CODE = '&company_code'
 AND EXISTS (SELECT 1 FROM sop_property_master
 WHERE property_type = 'JNSSO' AND property_key IN (SELECT field_service_rep FROM
 sop_service_request_job ssrj)) I want sum(amount) from sop_travel_living column...in above query
The structure of sop_travel_living is as under:
SQL> desc sop_travel_living;
Name Type Nullable Default Comments
TL_ID NUMBER(2)
SERVICE_REQUEST_ID VARCHAR2(20)
REPORT_ID NUMBER(2)
DATE_OF_TL DATE Y
TYPE_OF_TL VARCHAR2(100) Y
CURRENCY VARCHAR2(50) Y
AMOUNT NUMBER(12,2) Y thx...

Can anyone pls explain

Can anyone pls explain this part of the code.
DateFormat dateFormat = new SimpleDateFormat ("MM/dd/yyyy");
Date birthDate = dateFormat.parse (birthDateString);
Calendar day = Calendar.getInstance();
day.setTime (birthDate);
int day = day.get (Calendar.DAY_OF_MONTH);
int month = day.get (Calendar.MONTH);
int year = day.get (Calendar.YEAR);

Well, read my comments prior to each statement below...
You should also consider reading the API docs for the used classes, if you need more details...
// Crate a new DateFormatObject for formatting dates according to the specified pattern
DateFormat dateFormat = new SimpleDateFormat ("MM/dd/yyyy");
// Parse the provided String into a Date object
// Note that if the String does not provide for a valid Date you'll get an exception
Date birthDate = dateFormat.parse("30/08/1980");
// Get a new calendar instace
Calendar day = Calendar.getInstance();
// Reset the date in the calendar to the newly created date object
// Now the calendar represents the date in the day object
day.setTime (birthDate);
// Get the day of the month from the calendar
// Note that your code snippet contained int day = ... this will cause an exception as day was already
// defined!
int d = day.get (Calendar.DAY_OF_MONTH);
// Get the month of the year from the calendar
// Note that Jan will be returned as 0, so if you have to add one to the retrieved month value
int m = day.get (Calendar.MONTH);
// Get the year from the calendar
int y = day.get (Calendar.YEAR);Hope that helps...

Can anybody pls explain me this Reflections stuff?

Hi All
Can anybody pls explain me this Reflections stuff? is this related to singletons in java

Maybe you could give us a bit more information where
you need help, for all full coverage i suggest the tutorial too.

Could you pls answer this

What all the thing should be used in order to improve the performance and what all the thing should be avoided ?
Explain abt control brk statement ?
Could you pls give me clear explanation for CHECK,EXIT,STOP ?
In real time, what is the steps which is used for transfer data - BDC
whether call transaction,session method pls explain it
And also explain about the include statement used in BDC
Could you pls answer this

Hi
All this AT NEW, AT FIRST, AT END OF and AT LAST are called control break statements of Internal tables and are used to calculate the TOTALS based on sertain key fields in that internal table
FIrst to use these statements the ITAB has to be sorted by the key fields on whcih you need the SUM of the fields.
Some time you will get * when moving data from this int table to other table using these commands
so you have to use
READ TABLE ITAB INDEX SY-TABIX in AT..ENDAT..if you are using other fields between them
DATA: sflight_tab TYPE SORTED TABLE OF sflight
                  WITH UNIQUE KEY carrid connid fldate,
      sflight_wa LIKE LINE OF sflight_tab.
SELECT *
       FROM sflight
       INTO TABLE sflight_tab.
sort sflight by carrid connid.
LOOP AT sflight_tab INTO sflight_wa.
AT NEW connid.
    WRITE: / sflight_wa-carrid,
             sflight_wa-connid.
    ULINE.
ENDAT.
WRITE: / sflight_wa-fldate,
           sflight_wa-seatsocc.
AT END OF connid.
    SUM.
    ULINE.
    WRITE: / 'Sum',
              sflight_wa-seatsocc UNDER sflight_wa-seatsocc.
    SKIP.
ENDAT.
AT END OF carrid.
    SUM.
    ULINE.
    WRITE: / 'Carrier Sum',
              sflight_wa-seatsocc UNDER sflight_wa-seatsocc.
    NEW-PAGE.
ENDAT.
AT LAST.
    SUM.
    WRITE: / 'Overall Sum',
              sflight_wa-seatsocc UNDER sflight_wa-seatsocc.
ENDAT.
ENDLOOP.
BDC
BDC:
Batch Data Communication (BDC) is the process of transferring data from one SAP System to another SAP system or from a non-SAP system to SAP System.
Features :
BDC is an automatic procedure.
This method is used to transfer large amount of data that is available in electronic medium.
BDC can be used primarily when installing the SAP system and when transferring data from a legacy system (external system).
BDC uses normal transaction codes to transfer data.
Types of BDC :
CLASSICAL BATCH INPUT (Session Method)
CALL TRANSACTION
BATCH INPUT METHOD:
This method is also called as CLASSICAL METHOD.
Features:
Asynchronous processing.
Synchronous Processing in database update.
Transfer data for more than one transaction.
Batch input processing log will be generated.
During processing, no transaction is started until the previous transaction has been written to the database.
CALL TRANSACTION METHOD :
This is another method to transfer data from the legacy system.
Features:
Synchronous processing. The system performs a database commit immediately before and after the CALL TRANSACTION USING statement.
Updating the database can be either synchronous or asynchronous. The program specifies the update type.
Transfer data for a single transaction.
Transfers data for a sequence of dialog screens.
No batch input processing log is generated.
Differences between Call Transaction and Sessions Method:
Session method.
1) synchronous processing.
2) can tranfer large amount of data.
3) processing is slower.
4) error log is created
5) data is not updated until session is processed.
6) generally used for back ground jobs.
7) at atime we can update to more than one screens.
Call transaction.
1) asynchronous processing
2) can transfer small amount of data
3) processing is faster.
4) errors need to be handled explicitly
5) data is updated automatically
6) for background n fore ground jobs.
7) at atime we can update to a single screen.
For BDC:
http://myweb.dal.ca/hchinni/sap/bdc_home.htm
https://www.sdn.sap.com/irj/sdn/wiki?path=/display/home/bdc&
http://www.sap-img.com/abap/learning-bdc-programming.htm
http://www.sapdevelopment.co.uk/bdc/bdchome.htm
http://www.sap-img.com/abap/difference-between-batch-input-and-call-transaction-in-bdc.htm
http://help.sap.com/saphelp_47x200/helpdata/en/69/c250684ba111d189750000e8322d00/frameset.htm
http://www.sapbrain.com/TUTORIALS/TECHNICAL/BDC_tutorial.html
Check these link:
http://www.sap-img.com/abap/difference-between-batch-input-and-call-transaction-in-bdc.htm
http://www.sap-img.com/abap/question-about-bdc-program.htm
http://www.itcserver.com/blog/2006/06/30/batch-input-vs-call-transaction/
http://www.planetsap.com/bdc_main_page.htm
call Transaction or session method ?
Regards
anji

Pls explain me the use and purpose of following Function modules

pls explain me the use and purpose of following Function modules
1. G_MAX_PERIOD_AND_OFFSET_GET
2. DEQUEUE_E_TABLE
3. FI_COMPANY_CODE_CHECK
4. G_PERIOD_GET
5. alv_display_function
6. G_SET_GET_ID_FROM_NAME
thanks ,
phyrose

1. G_MAX_PERIOD_AND_OFFSET_GET
For given No. of period & periods it gives the offset
2. DEQUEUE_E_TABLE
To Unlock the table records
3. FI_COMPANY_CODE_CHECK
To validate Company Code

4. G_PERIOD_GET
Returns no. of Posting period & Special period for give company code, posting date & ledger
5. alv_display_function -
No such FM exists

6. G_SET_GET_ID_FROM_NAME - Use this module to derive the internal set Id from the name that appears on the user interface, for example, in order then to import the set (see the function group documentation).
The function module first determines a candidate list of sets based on the set name and the class that might have been specified that could match the set name. The class can also be masked (e.g. 000+ for all FI-SL sets, including dynamic sets).

Hi friends, pls explain What is DB lookups in xi

1)pls explain What is DB lookups in xi. how many types ?

Hi,
How to Perform DBLook-ups from XI Utilizing J2EE JDBC:
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/9aedca11-0d01-0010-3b90-9ea04182875f
XI lookups : When you want some data from R3 or DB into mapping , then you need to use some kind of user exit like Lookup, it will stop the execution process and goto respective database and get the data and back to mapping , this kind of machanism.
We will use DB lookups for any other database like DB,Oracle,SQL, MS Access..etc.
We will use RFC lookup for SAP R3 .
See thebelow links
DB lookup - /people/siva.maranani/blog/2005/08/23/lookup146s-in-xi-made-simpler
SOAP Lookup - /people/bhavesh.kantilal/blog/2006/11/20/webservice-calls-from-a-user-defined-function
Lookup - /people/alessandro.guarneri/blog/2006/03/27/sap-xi-lookup-api-the-killer
Also read thru this to get more idea on lookups - http://help.sap.com/saphelp_nw04/helpdata/en/cf/406642ea59c753e10000000a1550b0
Lookups in XI made simpler - /people/siva.maranani/blog/2005/08/23/lookup146s-in-xi-made-simpler
How to check JDBC SQL Query Syntax and verify the query results inside a User Defined Function of the Lookup API -
http://help.sap.com/saphelp_nw04/helpdata/en/2e/96fd3f2d14e869e10000000a155106/content.htm
/people/prasad.illapani/blog/2006/10/25/how-to-check-jdbc-sql-query-syntax-and-verify-the-query-results-inside-a-user-defined-function-of-the-lookup-api
Lookups - /people/morten.wittrock/blog/2006/03/30/wrapping-your-mapping-lookup-api-code-in-easy-to-use-java-classes
Lookups - /people/alessandro.guarneri/blog/2006/03/27/sap-xi-lookup-api-the-killer
/people/siva.maranani/blog/2005/08/23/lookup146s-in-xi-made-simpler
http://help.sap.com/saphelp_nw04/helpdata/en/cf/406642ea59c753e10000000a1550b0/content.htm
/people/sap.user72/blog/2005/12/06/optimizing-lookups-in-xi
Lookups with XSLT - https://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/8e7daa90-0201-0010-9499-cd347ffbbf72
/people/sravya.talanki2/blog
https://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/05a3d62e-0a01-0010-14bc-adc8efd4ee14
How we have to create the lookups?
Check this weblogs with some screenshots on how to achieve this:
/people/siva.maranani/blog/2005/08/23/lookup146s-in-xi-made-simpler
/people/sravya.talanki2/blog/2005/12/21/use-this-crazy-piece-for-any-rfc-mapping-lookups
/people/alessandro.guarneri/blog/2006/03/27/sap-xi-lookup-api-the-killer
/people/sap.user72/blog/2005/12/06/optimizing-lookups-in-xi
/people/morten.wittrock/blog/2006/03/30/wrapping-your-mapping-lookup-api-code-in-easy-to-use-java-classes
Regards,
Priyanka.

Can anyone pls explain about SSR in WebdynPro application?

Hi,
Am having the webdynpro code.I that code they are having one onclik event.When they are clicking on that button link they are returning SSR.handle(parameters).But i cud not found the definition of SSR.handle(parameters) function.Can anyone pls explain what exactly SSR and where they have the definition of that function?
Rgds,
Murugag

Hi,
SSR or server side rendering is a location-independent rendering method of the Webdynpro framework.Because of the strict separation of layout and content, the framework supports location-independent rendering (client-side versus server-side rendering). In other words, depending on the capabilities of the client device, an HTML page can be rendered either on the server or the client.
A simple browser (simple client) may not support client-side scripting or processing of XML transformations so this client may require that the server generate the HTML page before sending it to the browser. More powerful browsers (advanced clients) can inject the content into the page on the client using XML and JavaScript. This location independence is purely configuration driven and does not require modification to either the application code or the presentation code.
Just verify if your browser is javascript enabled or not.
Regards,
Satyajit.
Message was edited by: Satyajit Chakraborty

Pls explain

Hi,
Could anyone pls tell me what actually it means by doing this:
Map map = new HashMap(); or Map map = new HashTree();
Actually Map is an interface and HashMap implements it..But if we do like this
HashMap map = new HashMap(); still we will be able to inherit the properties of Map..So why do we need to create an Object HashMap and put the reference in the Map instead of HashMap.
Anything which clearly explain this concept is of great help
Also is it possible to put the reference in an Abstarct Type like this
SomeAbstartClass a = new ClassExtendsTheAbstractClass();
Thanks...

For short, if a class extends A, it can be cast as an A or any superclass of A.
If a class implements interface B, it can be cast as a B or as any superinterface of b.
Longer answer: Making a class abstract means that while it is a real class, the implementation details have been left until later to specify. For a good example of thing, take a look at java.awt.Graphics, an abstract class that you probably use all the time without realizing it is abstract. What is the actual class that finishes Graphics? The answer is it's an OS / platform specific thing, but it doesn't matter.

Can someone pls explain me (networking, DNS)

hi guys,
can some1 pls explain me what is hostname in the following record:
mysite.com. IN SOA hostname.mysite.com. admin.mysite.com. (1; 3h; 1h; 1w; 1h)
is it the name of my network interface ?
many thanks
Alex

ok, it looks like..
now to configure the MX record shall i point it to m0.mysite.com?
the thing is: i actually don't quite understand what is hostname (network interface) and host of my domain. in windows i came from there was a computer name (any name for local network use) , but i never used it in MS Exchange. i used to have an MX record pointing to mail.mysite.com, but in fact the machine's name was M0.
will highly appreciate some insight on this subject.
many thanks
alex

Pls explain usage of proxy.

1) pls explain usage of proxy and what is the abap proxy.
tell me step by step.

ABAP Proxy Runtime
http://help.sap.com/saphelp_nw04/helpdata/en/02/265c3cf311070ae10000000a114084/frameset.htm
ABAP CLIENT PROXY
/people/ravikumar.allampallam/blog/2005/03/14/abap-proxies-in-xiclient-proxy
ABAP SERVER PROXY
/people/siva.maranani/blog/2005/04/03/abap-server-proxies
This material will help you a lot.
regards
Nisar

What is star schema - pls explain with example

Hai.
what is star schema - pls explain with example
thanks in advance
Giri

Hi Giri,
SAP's BIW employs extended star schama
The extended star schema consists of a fact table (in two parts, E and F - f is the inbound table, E long-term storage). Dimension tables are connected to the fact tables via the DIMID(dimension id) which is a generated value and is stored in both dimension and fact tables. In addition, the dimension tables are connected to tables which hold master data values (or bind the dimension table to tables that hold the values), such as S tables, P, Q, X, Y. These dimension tables hold SIDs, again generated keys which relate values in the dimension table (the DIMIDs) with master data values. Thus, at the time of the query, join operations ensure that the master data values can be merged with the key figure values stored in the fact tables.
Truthfully, one does not need to understand this schema extensively in order to model in BI in SAP NetWeaver. It helps to understand master data, navigational attributes, etc. Otherwise, simply model the key figures in the fact table and the characteristics into dimensions and you're good - the application generates the star schema for you - you don't have to specify it.
See the transaction "LISTSCHEMA" which will show you the relationship between the F fact table and the other tables of the cube's star schema.
Also follow the link for more info:
http://help.sap.com/saphelp_nw04/helpdata/en/4c/89dc37c7f2d67ae10000009b38f889/content.htm
Thanks for any points you assign.
Regards

Pls explain me that

Dear All!
I hope somebody can explain me these quetions understandable:
Suppose the following scenario is given:
How are below itemized elements to be rank or arranged?
What are their functions ????
Are they really all necessary ?
Pls explain me that. It s very important
Regards
sas
WebDynpro Components
Componentxxxx         -> self explanatory
   Component Controller -> self explanatory
    InterfaceComponent       ??????
    Impelemented Interfaces ??????
     Interface Views         ??????
      Custom Controllers     ??????
       Message Pool      -> self explanatory
        Used Models             ??????
        UsedWebDynproComponents ??????
        Views           -> self explanatory
        Windows          -> self explanatory

Interface component- Configurable user interface (UI) components are reusable templates designed to simplify the creation of screen layouts in Web Dynpro. You use these UI components in support of the uniform layout and navigation paradigms of user interfaces in that they can be individually configured for use in different applications as per the intentions of developers or users.
By reusing existing UI components, you take advantage of already configured functions without needing additional coding. This pattern-based approach is therefore ideal for user interface generation. All patterns use the SAP UI development environment Web Dynpro.
Implemented Interfaces - refer this link
http://help.sap.com/saphelp_nw70/helpdata/en/6c/bd896e6661f04b9c8b2916aed3aadc/content.htm
Custom Contrllers - why we need Custom controllers in Model Applications
and the other things are pretty simple and self explanatory
Regards,
Venkat

Pls Explain About Iboats In Obiee step by step

Hai
Pls explain Step by Step for i boats so That i can follow the steps and practice according to that
Sekhar.P

Hi,
Your requirement will be fullfilled by sub-contracting process, the steps are described in below lines:-
u2022 Create material in MM01
u2022 Create BOM in CS01
u2022 Have routing in CA01
u2022 Create sub-contracting PO with item category L - subcontracting for external procurement in ME21N, with confirmation control as inbound delivery.
u2022 Transfer goods to subcontractor with movement type 311E, using t.code ME2O. (Create an outbound delivery)
u2022 Create excise challan J1IFQ
u2022 Receive the goods from subcontractor via MIGO/ inbound delivery (Vl31n) if you have selected the confirmation control in PO.
u2022 Execute J1IFQ for reconciliation.
u2022 Update the challan via J1IF13.
Assign the sub-contracting delivery type to a shipping point under t.code OMGM.
hope this will help.
regards
Vivek.

Pls explain abt prototype

pls explain abt prototype and its use in indesign scripting

One simple example where prototyping could be very bad: function1(); function function1(){ Array.prototype.getItemIndex = function (item){ for(var i=0;i<this.length;i++){ if(item==this[i]){return i} } return undefined; } var array = [1,3,5,2,4,6]; DoSomething(); if(array.getItemIndex(10)==undefined){ alert("undefined");//do something } else{alert("defined")}//do something else } function DoSomething(){ Array.prototype.getItemIndex = function (item){ for(var i=0;i<this.length;i++){ if(item==this[i]){return i} } return -1; } //do some stuff... } Now, the creator of function1 would expect his script to work properly -- and it will as long as he doesn't include DoSomething() in his script. Once he includes DoSomething() in his script, the public Array object has been changed to conflict with his script. The public objects are outside of the scope of namespaces. Both of these prototype methods are perfectly legitimate, but will conflict with each other, and you'll have a **very hard time** tracking down the problem!!! This kind of thing can very easily happen with nested scripts especially when event handlers are invloved. The DoSomething() function might not even be in your script, and you might not know of its existence... Of course using private scripting engines avoids these issues when used carefully, but I'd rather keep everything in its own namespace and safe from any chance of conflicts... -- Harbs http://www.in-tools.com

Pls explain this

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