I am still confused with Validation and Invalidation of the component in Flex. Could anybody please give me simple comparison about what Validation can do which invalidation cant and vice versa.
I really appreciate your any help.
Thanks.
Although I do agree with the comments, this is pretty well documented I think your just missing the overall relationship between "invalidation" and "validation" methods. Basically whenever you're making a call to invalidate somethings, whether it's the display list, the size, or the properties then all your doing is telling it to set a boolean flag for one of those (any time you modify a property that will modify any of these three it will call the appropriate invalidate method such as invalidateProperties when set width is called). When the next enter frame/render happens, it will check the flags and if any of them are set to invalid it calls the corresponding validation method (updateDisplayList, commitProperties, measure).
To see the code for yourself in FB/Eclipse hit Ctrl+Shift+T and pull up UIComponent, hit Ctrl+O once UIComponent.as is opened and type in validateNow you can see the method body is 1 line and there's a nice ASDoc comment there explaining what it does. Better yet you'll see it calls validateClient on a ILayoutManager, pop open LayoutManager (Ctrl+Shift+T again) look at validateClient, it explains basically what I do here.
I think this is where you're coming from because I was in that boat once too, not understanding the relationship between updating a property and it affecting it's siblings/parent/children but it's really key to reducing processing load since a property can be modified multiple times between frame refreshes and it doesn't need to re-calculate everything around it until it will actual be redrawn.
The problem being that sometimes you want to modify a property and immediately (that is on the next lines execution) be able to see how it's side affects have modified other parts of the layout, in this case you can call validateNow() after modifying a property forcing it to immediately update all of that even if it may happen multiple times before a redraw occurs. This is generally not a great practice since it usually means undesired cpu time is wasted, but sometimes it's the easiest option.
Related
I need to subscribe to the app-db for a value that I want to check only once when the parent component is rendered. For example, when I click a button "Click me", and there's a certain on-click event being processed, whose status I have saved on the app-db with the list of processes that are being done, I just want to check against that value once, and display two different components based on that value.
If the value is empty, I want to proceed with the normal event. If not, I'd like to show something else to the user, a popup for example.
Now the thing is that, because it's actively listening to the app-db, and the value is changing almost every second (or in a matter of milliseconds), the said popup appears, disappears, reappears, and disappears again super fast with each change to the app-db, which isn't helpful at all.
I would like to just subscribe once, get the value, and do the checks based on the value when the parent was first rendered. And then I'll do something to make that go away.
If I click the "Click me" button once again, that's only when I'd like for it to re-render.
I haven't quite been able to achieve this. I tried numerous methods such as introducing a delay during the dispatch of popup as well as after introducing processing states to the app-db in the first place hoping that since the data will already be in a steady state, it might not change as much, but now that I realize it's actively listening to it, it's expected that the values would change.
I did try using the subscription without the deref, but that only introduced an error to my frontend, so I'm not sure which way to go now.
My error with the component diappearing/reappearing turned out to be triggered by something else. A conflict/mismatch with popup-ids and a dispatch to clear one popup leading to destroying all of them.
But to answer the question, it works when you introduce a (fn []) block after the let binding where you actually do the subscription, and calling the components from inside the fn.
Here is the website I am trying to access. I dont want the default tab (Day) though, I want to select the Season tab
https://www.eex.com/en/market-data/power/futures/uk-financial-futures#!/2017/05/23
The link appears to be exactly the same whichever tab is chose making differentiation impossible as far as I can tell.
Any help on this would be much appreciated, using whichever programming method and language is appropriate.
Kind Regards
Barry Walsh
The URL does not change since this is an ajax request, which you can see from MarketDataTableAController's getPageData function. You can read about them here https://developer.mozilla.org/en-US/docs/AJAX/Getting_Started
Ive inspected your html and you seem to be using angular. On further inpection you can see that the tabs have ng-click="setActiveTab(tab)" attribute on them. So whenever user clicks, this function gets executed. It is a matter of using this function with the appropriate tab object to get the content to change. You for example could put setActiveTab(tab) into your controller init method since setActiveTab() calls the forementioned getPageData() function to update the page.
Also the tab you are looking for is page.tabs[5] ($parent.page.tabs[5] if referring from TabController) since this is the tab with the label of season. Pass that to setActiveTab() and it should show you the season instead.
However this might not be a good solution since the tab array ordering might change. Then you would need to loop over all objects in page.tabs and see if tab.label === "Season" and pass that in the function instead or better yet use the $filter service provided by angular which would look more cleaner.
Your code source also seems to be minimized and its not very easy to read.
In VS 2015, only when in Razor (.cshtml) files, roughly half of the time the autocomplete/suggestion list/intellisense doesn't work correctly (sorry, not sure the actual term... when you type an object and hit . and the list of properties and methods shows to select from)
The behavior is that when I hit ., the list popups up for a fraction of a second and then closes. It happens so fast I try to do a quick Backspace, ., Backspace, . cycle a few times to at least see the name I need, but I usually cant' get it and end up having to find the exact name elsewhere from code. Extremely irritating...
It happens sporadically with no real pattern I can find. Here's patterns that I've ruled out:
The file that's open doesn't seem to matter.
Whether or not I close/reopen the file doesn't seem to matter
Whether I navigate to another file and back doesn't seem to matter
It will work/not work multiple times on and off throughout the same file
It doesn't seem to be relevant to any particular object/property/method
I've checked all my options (there doesn't seem to be Text Editing options for Razor?), have tried clearing caches, the reloading solution/projects, restarting VS, all of which seem to still provide no pattern.
Has anyone come across this and have any ideas of where else I can look to fix it?
Example
Here's an extremely simple example... new project, very little code/files, very simple view. Where the Model. stops, I should have the usual base methods, and an 'Items' collection. It pops up for a split second then disappears... no lambdas/complex view parsing involved (this is reproducible as well):
Update: Patterns
Things I've noticed:
If I'm entering a #model ns.ns.ns.type, it rarely happens toward the "base" end of the namespaces. It's as I get further towards the type that it happens. This one is intermittent.
In some cases, it works perfectly fine, every single time. For example, I often use DevExpress tools, and have never seen the behavior on any of their extensions (so, #Html.DevExpress(). (and other similar, not necessarily DevEx models) will never cause a problem)
It happens almost all the time when I'm accessing my #Model (which is where I most want it!). I've found some cases where this is reproducible every time (see above example), but it's about 90%+
Occasionally, as I work through the object tree, one will fail while the next works (ex: #models ProjName.Web.App.Subscriptions.Models.AccountCreateVM... it might fail on Subscriptions but work fine on Models)
Occasionally, beginning to type the name within autocomplete kicks it back into gear and it starts working again. In the above example, starting to type Acc for AccountCreateVM causes it to start working again.
I haven't found the root cause, but in all cases, CTRL+SPACE works. This isn't the best, but light years better than nothing at all.
(this shortcut is not one I've used in the past, so this is likely standard behavior, but...) If you're at the dot Model. and autocomplete list disappears, CTRL+SPACE consistently brings it back up, and when it does come back, it stays! If there's only one possible autocomplete member, it'll auto-fill the member for you upon CTRL+SPACE
This happens for me all throughout VS2015 during lambda statements.
It happens when editing code "mid-document", as in, if there is anything besides a ) or } following where I'm typing. VS appears to be struggling to tell where the current statement ends & the next statement begins.
The following code will consistently fail to trigger Intellisense at the period, even when explicitly invoked.
var subset = initialSet.Where(x => x.
var result = new Whatever();
In Razor, it is very common to be editing code between existing text and using lambda statements:
<strong>#Html.DisplayFor(m => m.</strong>
This is probably why you only experience this in Razor.
The way I work around this bug is just to write the ) to close the method.
var subset = initialSet.Where(x => x.)
var result = new Whatever();
<strong>#Html.DisplayFor(m => m.)</strong>
Intellisense can then be triggered on the period.
If you're using a method that requires a minimum of more than just the lambda (like RadioButtonFor), you'll also need to put in a comma for each of the extra parameters.
<strong>#Html.RadioButtonFor(m => m.,)</strong>
If Intellisense is appearing, but immediately disappearing again, the best solution I've found so far is to just type a few letters of any known member, then using Ctrl-Left to skip back to the period, and trigger Intellisense again (Ctrl-Space or backspace-retype). This usually gets it to appear and stay. You'll have to delete the characters you typed afterwards, which can be frustrating.
Just make sure the ) does not touch the text you are editing, and the popup will stay up.
Instead of...
#Html.Partial("ManageGrid", Model.)
Use...
#Html.Partial("ManageGrid", Model. )
The intellisense seems to get confused by touching close parenthesis. Not ideal, but this was the only way I could get it to work for me consistently.
In my specific case, i was able to solve the problem by installing the latest version Microsoft ASP.NET and Web Tools.
https://marketplace.visualstudio.com/items?itemName=JacquesEloff.MicrosoftASPNETandWebTools-9689
Once I installed it, the problem was gone. It is likely that this update fixed something that could be fixed with an older version, but either way I'm happy.
(I found this in Visual Studio under Tools->Extensions and Updates...->Updates->Visual Studio Gallery)
I had the same error and I fixed it by deleting all the files of the component model cache.
This is the path:
Users\YourName\AppData\Local\Microsoft\VisualStudio\14.0\ComponentModelCache
Hope that helps
I use ctrl+j as a temporary solution when I know the content.
Or keep writing without right parenthesis can use the completion:
#Html.LabelFor(m => m.Name
Whenever this annoying thing happens to me, I just put an extra dot and then it works. I have to put the extra dot every time. For example, if I write this and intellisence flashes and disappears:
#Html.TextBoxFor(m => m.
then I just do this:
#Html.TextBoxFor(m => m..
And intellisense will now show after first dot. I have made this a habit until MS has a fix for it.
Instead of...
#Html.Partial("ManageGrid", Model.)
Use...
#Html.Partial("ManageGrid", Model.
I am writing a Google Chrome Extension and trying to make the transition to coding in HTML, CSS and Javascript from the kind of coding I did 40 years ago. It's a big learning curve but a little bit of console logging would help a lot. (Who remembers the green phosphor displays on the old iron-core memory Sperry Univacs? Now there was a console that could tell you what was going on - mount a tape, change a diskpack or put more paper in the printer.) But I digress.
Just a few days ago, I was able to send messages to the Google Chrome DOM Inspector console log from my content script or background page like this:
console.log="RECEIVED REQUEST FROM CONTENT SCRIPT PEEK.JS";
Later if I inspected the page where that code was injected, I would see that exact same message on the console. If that line executed four times, I would see four instances of that messages in sequence on the console. It was simple but beautiful.
Now, nothing appears on the console unless I type in "console.log" and in this case I see only the last instance of the message. What's the problem here? Did I toggle something off in the debugger? Am I writing the code wrong? Should it be: "console.log("Message Here");" - (this always returns an error) ?
I have spent literally hours trying to find the answer to this question and I can only surmise that the question is so simple that even a well-educated child could answer it. The alternative is to spend more hours trying to find my bugs thru implication or from alert messages. Better to spend my hours learning how to effectively use the inspector for debugging.
For example, yesterday after restructuring what was once working code so that it would pass an array to background from content instead of background requesting each item successively from content, the extension broke, as might be expected. The console displays one error message: "Error during tabs executeScript: Unknown error." with a link that says "chrome/ExtensionProcessBindings:95" on the far right of that same line. Obviously the error message is almost useless. Clicking on the link brings me to the resources panel which displays a blank frame to the right with the words "background.html" This appears to be useless as well.
How is this information at all helpful? It took me another six hours to figure out that I had moved a variable definition to another place in the code so that it was not defined at the time the executeScript line was executed. Had the error message said that a parameter was undefined in executeScript, I could have found it in about ten minutes.
So back to the original question - I WANT A SIMPLE ANSWER - don't tell me to write a function. I saw the console displaying what I wanted two days ago without writing any functions.
Here is your SIMPLE ANSWER: Instead of
console.log="RECEIVED REQUEST FROM CONTENT SCRIPT PEEK.JS";
You should use
console.log("RECEIVED REQUEST FROM CONTENT SCRIPT PEEK.JS");
For console.log():
https://developer.mozilla.org/en-US/docs/Web/API/console.log
I would recommend searching the Mozilla Developer Network for documentation on JavaScript and many browser technologies.
My general suggestion to help with mistyped or out of scoped variables is to use strict javascript:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions_and_function_scope/Strict_mode
This makes certain JavaScript idioms into errors which are detected earlier, and which give more helpful diagnostics. (The quick version is to put the single line "use strict"; at the top of your js files, or if that causes to many problems you can put it as the first line inside any function to do function-by-function migration.)
The reason why console.log = blah would show blah on the console in some situations is that in JS, <left side> = <right side expression> is an expression which evaluates to the same value as just <right side expression>, but it has the side affect of also assigning to <left side>. (This is similar to C assignment expressions.)
Then, in the context you were in, the console will display the result of any expression evaluation. This is different from explicitly calling console.log() which will display the arguments as the intended side effect of that function.
So in that case you were overwriting the standard console.log function with a string, and the entire expression evaluates to that string value, and the console's builtin behavior (not the console.log() function!) would display the result of your evaluation.
In JS most things are mutable, and you can overwrite all kinds of fields and variables, so be aware of this potential gotcha!
Also, a general recommendation for seeking help on the web:
For sites like StackOverflow is to limit your post to a very specific single question. This is because people with similar problems will come here based on web searches or other links, and they need to figure out if this page helps them with their particular problem quickly. If they have to read through paragraphs with multiple questions or anecdotes, this really slows them down. I would guess that's why this question has been downvoted.
If you have multiple questions, make separate posts. StackOverflow isn't a good site for anecdotes about your experience in the past. FWIW- I personally found your background as a programmer on 70's era machines interesting, but many readers may get lost in the details. Those kinds of anecdotes could make a good blog post.
I found that I can write code just by typing everything or activate element, then click for example OnClick property and write code to between the sub-end sub lines.
One person I met said that one has always use mouse and select the property in which you want to write the code, as it might write something else to some files such that the code won't work.
Is this correct or are those two ways to write code equally good? I'm using Access 97.
The short answer is you CAN do it that way. But it doesn't mean you SHOULD.
With a little experimentation I've found that you can type in event subs directly in the code window, and their creation will be reflected in the properties window. This might not have always been the case in older versions of MS Access.
You can also create them by selecting the Control in the code window's top left pull down, and then selecting the event in the top right pull down.
Why would I choose to use the Code Builder (or at least the second option I provided). Because it prevents you from making mistakes. Both in the name of the control/event and in accidentally creating duplicate Subs. Both of which could be frustrating when debugging your application - how long could you spend looking for a bug because you added an extra "S" to an element name by accident. If you follow through from the properties window, you are guaranteed to be working on the right Sub and that it will be spelled correctly.
Note: I've also found that you can delete the entry in the properties window, but it leaves the code behind in the code window. So to make sure it is really gone, you do have to go into the code window and delete the Sub there.
That's not to say that I never do anything directly in the Code window like that - if I've renamed a control, I'll often update the name in the code window. But then I'll go back through the properties window to verify that I've re-connected the subs properly.
"Look, I'm running with scissors!"