RE: Validator's sucks ??
Using either customized Java code or regular expressions, a developer can ensure that any incoming form data is legal and valid. This is a tremendous help to any developer as it prevents bad data from being processed by their Action and, many times, causing the user to see annoying 500 errors. I'm not sure why any Action would bomb out from invalid data. If that happens, IMO, you're putting too much logic in your Action. IMO, data validation belongs at the BO level. No matter where your data comes from, your BO should decide for itself whether or not it's valid before it tries to process it. It shouldn't just assume that it will get valid data. For this reason, in one project I completed, we ignored client-side validation nearly completely, and instead relied on server-side validation coming from the BO's themselves. This way, no matter what screen tried to do what operation, correct error messages would be given back to the user and the screen would re-paint. This was a lot easier and more logical to me than having each screen (which is simply a view to data) know exactly what kind of data is valid for what it is displaying. Doing it at the BO level, if there is a change in one validation, it gets changed in one place, no matter how many screens can updated that piece of data. Much easier, IMO. So, I'd like the Validator framework to work at the BO level and the javascript/screen level, and skip the Action level altogether. I prefer my Actions to be really, really stupid - traffic-controllers only, not data handlers. Matt Kruse
Eclipse-like web view framework for struts?
I would like to build a web app that functions like a control panel with multiple views of data that the user can close, resize, etc. What I keep coming back to is wanting something similar to the Eclipse development environment, where I can pick my views and position them on the screen and have the layout be customizable by the users. Except in a browser, probably using frames and/or iframes. Somewhat like a portal, even, but not exactly. My target browser will be IE only, so I can do lots of cool things, but I don't want to get into active X or anything like that. Purely HTML/CSS browser-based interface. Is there any kind of framework or UI tool which will get me going with this kind of approach? Matt Kruse
RE: question on javascript...
This is a basic question... Can I find the index of a select box,
if I have the value or the text ???
document.formName.optionName.options[C].selected=true
-- This won't work!!
You need to loop through each option, checking to see it's value and then
checking it.
var s = document.formname.optionname;
for (var i=0; is.options.length; i++) {
if (s.options[i].value==C) {
s.selected=true;
}
}
Or, using functions at http://www.mattkruse.com/javascript/validations/ you
can do:
setInputValue(document.formname.optionname,C);
Be careful - multiple options are allowed to have the same value!
Matt Kruse
RE: swap values between two select boxes
I have two select boxes on my jsp page and each of them is multiselect set to true. I am trying to swap values between the two - is it possible ? I have a javascript library which will make this easy for you - http://www.mattkruse.com/javascript/optiontransfer/ Hope that helps! Matt Kruse
RE: Know of any good Calendar Tag Libraries? (Sorry, that was Aug 21)
I'm aware of Matt's Library (and I love it), but I don't want a pop-up, I want an in-page calendar. BTW, I'm going to be adding an 'inline' option to the javascript library, which will then find its way into the taglib also. Unfortunately, I've not had much time to work on it lately, so the taglib hasn't been updated yet. The other options out there seem pretty good, though. Matt
RE: Is it possible to remove *.do or /do/* from the URL
By that argument, GUI apps should not ever disable menu options that are not relevant to the current state of the computation either -- instead, they should just leave the option enabled and deal with it when the user selects it. :-) I don't think that's a fair comparison, because GUI apps have control over their interface. Web apps do not have control over their interface. If there was a standard way to tell all browsers to disable the back button on this page then I'd say yeah, go for it. But the nature of the web is that you do _not_ have control over the interface, and your app needs to respond to whatever the user does, rather than control what they do. The fact is that it is HARD to design an app for the web and implement it so that it works well in a browser. Not only is it hard, its nearly impossible. Why do you say this? Can you give examples of situations where a web app cannot behave in an appropriate way when a user chooses to use the back button? Every situation I can think of can be handled. In some cases, maybe the best handling is to simply tell the user you can't submit this page again, we're now going to take you back to the beginning. to avoid this, don't use the back button. But that's severe, IMO. Last resort. Non-trivial interactive applications (I'm not taking about adding a comment to a guest book; I'm talking about adding an order to a database) have the same kinds of ordering and transactional restrictions, whether you implement them in a client-server GUI in your favorite language, or as a webapp. It's a different beast. Even in processing an order, when the user must go down a path one step at a time, why can't the application handle the back button? What specific cases are there were using the back button just totally screws everything up in such a way that the web app could not handle it logically? Matt
RE: Is it possible to remove *.do or /do/* from the URL
The important principle here is Web Application != Web Site. Why? In many cases, it's the same difference. These days, web sites usually are web applications on the back-end. There are a lot of stupid users out there. In many cases, every attempt needs to be made to cater to them. If your users feel compelled to use bookmarks and the back button in your webapps, despite efforts to train them correctly, this is a pretty good sign that you have not provided enough suitable navigation controls in your basic UI. On the contrary, I'd say that if your web application can't handle the back button and bookmarking, then you've designed it incorrectly. ESPECIALLY if your users want to use them :) When web applications are done right, they have nice URL's, the back button can be used without causing any problems, and bookmarking is possible wherever it makes sense. IMO, there are too many lazy developers out there who do poor design and don't consider the 'Back' button, for example, then look for cheap hacks to stop the user from using it. Instead, they should think differently and handle these cases. It's sometimes more work, sure, but that's part of the job! Matt
RE: can't pass parameters
The other comments are probably valid, but I thought I would note this: onclick='document.forms[this.form].param.value=save ; This should be: onclick='this.form.param.value=save;' Matt Kruse
RE: Validator JavaScript and html:radio buttons
IIRC, it's invalid HTML unless exactly one of the radio button options is selected. That's not true. Not really. From the specs: QUOTE Radio buttons are like checkboxes except that when several share the same control name, they are mutually exclusive: when one is switched on, all others with the same name are switched off. The INPUT element is used to create a radio button control. If no radio button in a set sharing the same control name is initially on, user agent behavior for choosing which control is initially on is undefined. Note. Since existing implementations handle this case differently, the current specification differs from RFC 1866 ([RFC1866] section 8.1.2.4), which states: At all times, exactly one of the radio buttons in a set is checked. If none of the INPUT elements of a set of radio buttons specifies `CHECKED', then the user agent must check the first radio button of the set initially. Since user agent behavior differs, authors should ensure that in each set of radio buttons that one is initially on. /QUOTE Authors _should_ pre-check one item, but are not required to. Since it's not possible in most UI's to set a radio group back to no items selected it's usually bad design to have none selected initially. The user can't restore the form to its original state if they accidently click in the wrong place. I would be able to tell you why the JS is failing if you post the source, but a better solution might be to re-think your design and consider whether a group of radio buttons is really the interface you want to use. Matt Kruse
Calendar Popup taglib
I now have a (very beta) version of the calendar popup taglib available for download and testing: http://www.mattkruse.com/javascript/javascripttoolbox.zip I'm not sure if it's in a correct or usable form as-is, but anyone familiar with Struts should be able to get the examples running in their container of choice. I have a few more things to add (like setting disabled dates, etc) but I wanted to get some feedback now before cleaning everything up and adding more functionality. If you have any thoughts, please let me know so I can make it more useable to the struts community! Matt Kruse
RE: is there any Dependable Option List Tag ?
If we have two related Drop Down boxes in a Form and need to populate those when we load the page and when we change the value in the first drop down we need to load the corresponding values in the second .. Can any TagLib supports this.. I don't have it in the form of a taglib (yet) but I do have javascript to handle this: http://www.mattkruse.com/javascript/dynamicoptionlist/ You can just loop through your array list of values or whatever and print out the require javascript lines. Some day I'll have a tag lib created to make the whole process less painful... Matt
Can an INPUT tag know its form name? Also, application resources...
In writing a taglib for my calendar popup, I've come across two questions:
1) I need to write javascript which references the generated input tag. To
do this, I need to know the name of the form that it is contained in to get
a javascript reference to it. If no form name is found, I'll default to form
[0]. This isn't working:
protected String getFormName() {
// Acquire the form tag we are associated with
FormTag formTag =
(FormTag)pageContext.getAttribute(Constants.FORM_KEY);
if (formTag==null) {
return 0;
}
else {
return '+formTag.getName()+';
}
}
I took this from the html:option tag as an example. Is this not possible
for the form tag?
2) I have a .properties file for my taglib which defines standard text and
default options. It would be great if a user could over-ride those settings
with messages in their own application-specific MessageResources. Is there a
generalized way, in my taglib code, to get a reference to the application's
message resources so I can search for keys that over-ride my defaults?
The other option I thought of is that the developer can extend my taglib
with their own and point to their own MessageResources file, but this isn't
as slick.
Any other options?
PS: Just have to clear up these two things and write more examples and it'll
be ready for testing...
Thanks!
Matt Kruse
Suggestions for Calendar Popup taglib?
I'm going to have some free time soon and I plan to convert my calendar popup javascript (http://www.mattkruse.com/javascript/calendarpopup) into a tag lib to be easily used in struts apps. If anyone has suggestions on how it should work or features it should support, please let me know! Also, should it be extending the struts html:input tag, or since those will one day go away, should I be extending a different taglib? I'm more familiar with the struts tags (extended them before) but I want the tag to be useable by the majority of struts developers :) Matt
RE: Suggestions for Calendar Popup taglib?
When we implemented out calendar one of the things we needed to do was make holiday dates unchoosable. So I'm not allowd to make a booking on 25th Dec etc. It might be worth thinking of some way in which you can pass in a collection of dates that are highlighted differently/disabled. That's already supported in the javascript library, so there will be corresponding tag arguments to pass these into the java side of things. Perhaps something that will take an ArrayList of Date objects to be disabled? Then the styles of the calendar will take care of how to display these dates which are not selectable. Matt
RE: Suggestions for Calendar Popup taglib?
Does this mean it'll write JS for the popup calendar too? Yes, definitely. I might include the full JS source as a tag too, so you could just do mk:calendar-src/ at the top of your page and all the required library source would be written out. Or you could manually link to the libraries. Not sure what the standard way to do this is when a tag requires javascript libs. I like the div version - which requires a hidden div and such - so I hope you'll incorporate this. Yup, will do. A newer (unreleased) version of the calendar popup automatically generates a DIV object and inserts it into the page source, so you don't even need to have an empty div sitting there. But for now, I'll just write out the DIV tag from the doStartTag() method so the user doesn't need to worry about anything at all. I always use a image icon for my calendar links - so I'd like to see that as an option. Indeed, I have linkText and linkImage as properties, so you can use either one. Or neither, if you want it to popup onFocus of the form field. Options, options, options... Matt
RE: Suggestions for Calendar Popup taglib?
In working on this, I've come up with a couple of things that would be very handy to have: 1) A simple dummy struts app which would be ready for me to plugin my taglib to test. I know that creating a little app won't take long, but a nice little starting point would be convenient. 2) Any type of documentation for the standard way to release taglibs. What directory structure and contents are expected? Is there a standard way to do it? Either of those would be helpful to me, if anyone can point me somewhere. Thanks! Matt -Original Message- From: Kruse, Matt [mailto:[EMAIL PROTECTED] Sent: Monday, August 18, 2003 9:56 AM To: Struts Users Mailing List (E-mail) Subject: Suggestions for Calendar Popup taglib? Importance: High I'm going to have some free time soon and I plan to convert my calendar popup javascript (http://www.mattkruse.com/javascript/calendarpopup) into a tag lib to be easily used in struts apps. If anyone has suggestions on how it should work or features it should support, please let me know! Also, should it be extending the struts html:input tag, or since those will one day go away, should I be extending a different taglib? I'm more familiar with the struts tags (extended them before) but I want the tag to be useable by the majority of struts developers :) Matt
RE: Dependent select boxes
I have an application that uses dependent select boxes, ie, by picking one item in a select box, then the contents of the next one will be decided. I have a javascript library which does exactly this. Check it out: http://www.mattkruse.com/javascript/dynamicslelectbox/ Matt
RE: Cascade Select
(4.) Use JavaScript. Something along the lines of html:select property=yerFormProperty onchange=document.yourForm.otherSelectBox.value=this.value / This seems really obvious to me, though, so maybe I'm missing something. You can do the javascript approach easily using a library such as: http://www.mattkruse.com/javascript/dynamicoptionlist/ There are no struts tags to go along with it right now, but eventually, if I ever get the time, I'll be adding jar and tld files to make this integrate nicely with struts. Matt Kruse
RE: Submiting a form through a link
a href= onclick=document.forms[0].submit();return false;Click here/a The above code works for me. Not sure if the return false; has any impact - probably does nothing. The return false is definitely important. It tells the browser that, after running the commands in the onClick handler, it should NOT go to the href. If you return true (default) then the browser will go to the href after running the commands. In this case, if you aren't returning false, then the form will submit and the browser will immediately abandon that request and instead try to go to the href URL, making it look like nothing happened. Matt
RE: Indexed properties and JavaScript
I hadn't tryied this, and it has worked on IE 6 and Opera 7.1, but not on Netscape 7 ! Try this instead: document.forms['testForm']['att[0]'].value That should work in any browser. Matt Kruse
RE: Problems removing (expiring Cookie) in Action
Is there anything that I need ot be aware of in terms of expiring/removing a Cookie within an Action? I'm setting the maximum age to 0 and then adding the cookie back to the response and somehow that cookie shows up after I've forwarded my request to the next action. I'm I missing a step? The cookie will continue to exist in your request until the server sends the response back without the cookie, and the browser makes another request not including the cookie. If you are forwarding from one Action to another without redirect, you get the same request as the first action, and the cookies are still there. Unless I'mm understanding your situation incorrectly Matt Kruse
RE: Escaping ' and in bean:write output for javascript?
From: Gemes Tibor [mailto:[EMAIL PROTECTED]
addName('bean:write name=person property=lastname
filter=true/');
This filters the html sensitive chars.
Nope, that doesn't do the job (filter is true by default, btw).
It creates output like this:
addName('O#39;Reilly');
which causes javascript errors.
Instead, it should be:
addName('O\'Reilly');
Since I already had my own taglib which wrapped bean:write, I just added
another attribute called javascriptEscape to be set to either true or false.
It does:
' to \'
to quot;
\n(newline) to \n (\\n)
\r(newline) to \r (\\r)
Matt
RE: Escaping ' and in bean:write output for javascript?
Which is exactly what the string taglib does from jakarta.apache.org, plus a lot of other cool things (think wordwrap and nl2br) I will check this out later. I just didn't want to introduce another taglib into this project at this point in the game. Too many unknown variables! I'm still not sold on the value of taglibs, but it's good to know that there are people out there solving the problems before I get to them :) Matt
Escaping ' and in bean:write output for javascript?
Simple question,
When I want to use bean:write to print a value into a JSP, to be included
as an argument in a javascript function, how can I escape the output in
cases where it has ' and and newline characters?
For example,
addName('bean:write name=person property=lastname/');
If the lastname is O'Reilly, this causes a javascript error because the
output looks like:
addName('O'Reilly');
When it SHOULD look like:
addName('O\'Reilly');
I don't see anything in the docs to handle this - do I need to extend
bean:write with my own taglib?
Matt Kruse
RE: Why is dbcp / pool removed?
The one included is not the same as what is in RC1, though, correct? I'm not sure what Ted changed but you may be correct that it's not exactly the same. You can still use DBCP, Struts just won't distribute it any more. If I move away from DBCP and try to use just the features included with RC2 (for now), it seems like there have been a lot of changes. GenericDataSource now handles all the pooling and stuff itself, instead of relying on BasicDataSource, which is fine. But, it also relies on GenericConnection, of which there are two versions - one for JDK1.3, one for JDK1.4. And the one for JDK1.3 will _not_ compile JDK1.4. (according to the docs). That's a bummer, because if I release an app with the 1.3 version packaged in, and the server is upgraded to 1.4, I'm going to assume that things will break? I'm not looking for a long-term fix, just a short-term switch to possibly avoid the problems that DBCP might have been causing for me. I'm just finding it a challenge to figure out which short-term fix to use. You're not tying your app to the container because you configure the DataSource implementation entirely in JNDI (my preference) or struts-config.xml. In struts-config.xml, if I define my type= to be a container-specific class, though, then it's no longer portable. Unless I'm completely misunderstanding what you mean, which is likely :) I'm going to explore better ways to handle db connections in the future, but as I said above, I'm just looking for a patch to address current problems with DBCP, so I want to keep defining my db conns in struts-config.xml, and I want to rely only on the classes packaged with struts (if possible). I'll experiment and see how it works! Matt Kruse
RE: Why is dbcp / pool removed?
The Struts distribution no longer includes DBCP but it does still work with it. You can continue to use DBCP in your app as you did before. I know :) But, I was having some problems already that I suspect are due to that way DBCP is (or isn't!) working, so I did want to replace it with the new approach in RC2, until I explore JNDI further. So, I don't want to use DBCP anymore, but I want to continue using struts-config to define my db so as not to disrupt the current state of the app too much. So I'm learning how the DBCP-independent RC2 handles the db connections all internally, and trying to figure out if that will work and what problems might exist with it. Having some luck so far, but I need to do a lot more playing around to make sure this doesn't replace my old problems with new ones :) Matt
Debugging Connection Pooling Problems? (dbcp, sybase)
Can anyone recommend a smart way to debug connection pooling issues? I'm using BasicDataSource, connecting to a Sybase11 server. It seems that every night, all idle connections are closed by the server (no app activity), but for some reason that's not detected by the connection pool. Our app hangs while trying to get a connection, and I can't figure out why. It doesn't even come back after the maxWait time and give me an exception - it just waits forever. I've logged the active and idle connection counts, and they are sitting at like 1-3 each, so it's not approaching the limits of 20 active and 4 idle. Here is my config inside of struts-config.xml: data-source key=TEST type=org.apache.commons.dbcp.BasicDataSource set-property property=defaultAutoCommit value=true/ set-property property=description value=TEST/ set-property property=driverClassName value=com.sybase.jdbc.SybDriver/ set-property property=maxActive value=20/ set-property property=maxWait value=1/ set-property property=maxIdle value=4/ set-property property=minCount value=2/ set-property property=validationQuery value=SELECT 1/ set-property property=password value=pass/ set-property property=url value=jdbc:sybase:myserver:9996/ set-property property=username value=user/ /data-source I've seen mention of the following items and I'm trying to learn more: - autoReconnect : Apparently set in the URL. Is this db-specific or jdbc-specific? - removeAbandoned : Not quite sure what this does or if it would help, given that I have a validationQuery? - testOnBorrow : Should this test the conn every time I get one? Isn't that the point of the validationQuery? Any ideas would be greatly appreciated. I'm trying to see under the hood of the connection pooling, but not much is exposed for me to look at. Matt Kruse
RE: Why is dbcp / pool removed?
Struts 1.1 includes its trusty old GenericDataSource but you can always plugin DBCP if you want. Hold on a second... Isn't GenericDataSource deprecated? I just recently switched from using GenericDataSource in my struts-config.xml (by specifying no type=) to explicitly using type=org.apache.commons.dbcp.BasicDataSource because of the docs in GenericDataSource. Is this no longer the recommended approach? Currently, I'm having some problems with pooling and idle connections which are closed by the db server actually being given back to my app (I suspect). Could this be related to the bugs in dbcp you are talking about? Using 1.1RC2, what is the recommended way to acquire pooled db connections? Matt Kruse
RE: Why is dbcp / pool removed?
Isn't GenericDataSource deprecated? Yes, it will be removed in 1.2 but is included in 1.1 for backward compatibility. The one included is not the same as what is in RC1, though, correct? I'm just trying to figure out exactly what is changed and what I need to start experimenting with... I recommend using the package distributed with either your container or your database. If you tie your app to your coontainer, then it's not very portable, no? I can develop in Tomcat and publish to JRun with no problems, and I like to maintain that :) I suppose for now a good plan would be to use GenericDataSource and research more reliable and portable options for conn pooling in the future? Perhaps by then DBCP will be cleaned up and a good stand-alone alternative. Matt Kruse
RE: calling actions directly
I read that one of the things about struts is the actions are only able to be called from the pages directly. Ie, you shouldn't be able to bookmark the actions themselves like: http://myhost/myaction.do Where did you hear this? That's totally not true - any action can be called directly as long as it has a mapping. It's just a URL. Otherwise, how would you enter the first action? :) Perhaps what you're thinking of is that JSP files should not be called directly or bookmarked. They should be hidden from the user completely, and only accessible through an action. Matt Kruse
Log file viewer servlet for log4j?
Is there a good pre-packaged log-file viewing servlet available anywhere? Preferrably something that could take my log4j.properties file as the only parameter and allow me to view all the different files I've defined, their backup files, etc, and page through or filter the contents. Even if it's a quick-and-dirty little utility, it might be useful to me. Any thoughts? Matt Kruse
RE: Possible Bug in FieldChecks.validateRequiredIf(...)
Am I correct in assuming that the following condition ((value != null) (value.length() 0)) should be (!GenericValidator.isBlankOrNull(value)). The reason my check is failing is due to the fact the value I'm checking is all white space (at certain times), and is selected from a select box. I disagree with your assumption that should fail a required check. In some situations, that may be a valid value to be submitted. It exists, and it has a value. A validation check for the field being required should pass. It sounds like what you want is a not blank validation, where a value consisting of all whitespaces, tabs, or newlines would fail. I think the two are not the same, but that's just my opinion :) Matt Kruse
RE: switch between selects
I'd like to allow a user to select items using a kind of switch lists. Do you know how to perform this using Struts ? Or maybe another method ? Unless you want to go back to the server with each click of 'add' and 'delete' etc (not recommended) you'll need to use JavaScript. I have a library which allows you to do exactly what you're asking for: http://www.mattkruse.com/javascript/optiontransfer/ Hope that helps, Matt Kruse
RE: html:option dependant on prior html:option
Is there a way to make a pull down menu using the Struts html:option tag dependant upon another pull down menu on the same page? Unless you want to go back to the server every time they change the first drop-down list (not recommended) then you'll need to use Javascript. I have a library to do exactly this: http://www.mattkruse.com/javascript/dynamicoptionlist/ This is #2 on my list of javascript libs I want to convert into struts tags, so hopefully in the near future creating dependent lists will be much simpler :) Matt Kruse
RE: How to change label on a html:file button
I would like to change the label: 'browse' on the button to some other text. Unfortunately, you can't. This is a limitation of HTML, not Struts. There are some really, really funks tricks with DHTML and hidden form fields, etc, which can simulate this, but trust me, you don't want to use them. The file input element is under the control of the OS, and you can't even have much control over the style and appearance of the browse button. Matt Kruse
RE: javascript nested:iterate property reference
I have to believe someone out there has done something similar and is as little expert in mixing javascript and struts as I am. As soon as I get extra time, I _will_ be putting this calendar into a struts taglib, so no one will need to fight this anymore :) I'll point out a couple of issues and hope that they will help you along: document.forms[0].elements['targetDate'].value = m + - + d + - + y; input type=text name=eventList[0].targetDate value=05-31-2003 'targetDate' is not the name of your field. 'eventList[0].targetDate' is. Technically, this is an invalid name for an input field, but we'll ignore that fact because it's now become more common with PHP and Struts and who knows what else creating this type of field name. To reference an invalid form field name like this, you will need to use a reference like this: document.forms[0]['eventList[0].targetDate'] But, since you're using the 'select' method, you don't even need to define the setReturnFunction or anything. Just use select() and pass it the form field to populate and format. So, I think what you really want is: a HREF=# onClick=cal1.select(document.forms[0]['eventList[0].targetDate'],'anchor1', 'MM/dd/'); return false; NAME=anchor1 ID=anchor1 Try that and see if it works :) Matt Kruse
RE: Calendar tag lib
http://www.mattkruse.com/javascript/ has a nifty calendar popup for a client side date picker. Now that I am getting into using Struts, I plan to wrap my javascript calendar popup inside a taglib to make integration easier. Watch the above URL in the next few weeks and it'll hopefully show up. Matt Kruse
RE: Calendar tag lib
Will it be i18N compliant? In what sense? The javascript itself is already able to be customized by changing day/month names, week start day, date format, etc. These will then become parameters in the taglib. Or do you mean that it should automatically do these things based on which locale is being used? I have to admit, I don't know anything about how Struts/taglibs handle that, so I will need to look into that as well. But my goal is to have it be as automated as possible with logical defaults, in addition to having everything customizable. If anyone has further thoughts, feel free to take this off-list and contact me directly! Matt
