Here, in my application, I need to implement the undo and redo functionality in one parent component. I also have a number of child components, and each of these child components contains one or more DOM elements, such as a textbox, checkbox, and delete icon.
So, in this case, if I make any changes to any DOM elements that are present in the child components, the changes should be detected and sent to the parent component so that it may perform an undo and redo.
• Undo is possible for the last five actions.
• Redo is available for the last five undo actions.
`<!-- Main component -->
<div>
<div>
<div>
<div>
<header [section]="section" [formType]="formType" [sectionIndex]="sectionIndex" [first]="first" [last]="last"></header>
</div>
<div >
<item-crud [section]="section" [formType]="formType" [sectionIndex]="sectionIndex"> </item-crud>
</div>
</div>
</div>
</div>
<!-- header -->
<div class="container">
<div class="col-md-5 pull-right vertical-center"><i (click)="undo()"></i><i (click)="redo()"></i></div>
</div>
</div>
<!-- item-crud -->
<div id="accord">
<div>
<div>
<div>
<div class="formContainer">
<div><date-stamp></date-stamp></div>
<div><text-field [sectionItem]="sectionItem"></text-field></div>
</div>
</div>
</div>
</div>
</div> `
In this case, if I make any changes to any DOM elements that are present in the child components, the changes should be detected and sent to the parent component so that it should perform an undo and redo for all the changes done.
Related
I have a number of controls declared like this.
<div class="row">
<div class="col-sm-12">
<div>Caption</div>
<input type="text" class="form-control">
</div>
</div>
Trying to refactor my code, I introduced a component to encapsulate this particular behavior.
<div class="row">
<app-textbox [caption]="'Caption'"></app-textbox>
</div>
The markup for the component is just a copy of the original code.
<div class="col-sm-12">
<!-- <div style="width:100%;"> -->
<!-- <div class=""> -->
<div>{{data?.caption}}</div>
<input type="text" class="form-control">
</div>
The problem arising is with the class row seems not to propagate to the component. It spreads to the full width (as it's set to 12 but it's not the width of the component holding the class row - it's smaller). Analyzing the markup in the console of the browser, I can see that the only difference is that there's a tag for the custom control injected in the structure like this:
div class="row"
-- app-textbox
-- -- div class="col-sm-12"
-- -- input
while the "old-style" generates this:
div class="row"
-- div class="col-sm-12"
-- input
One way to handle it is to set the columns on the component in the main page like this.
<div class="row">
<app-textbox [caption]="'Caption'" class="col-sm-12"></app-input-text>
</div>
There are, however, two issues that bother me with it making me feel reluctant to this approach. First one is that the component still gets a (very tiny) extra margin of 15px on each side relative to the enclosing component (all the item have it but the custom app-textbox gets it twice, probably due to encapsulation). The other issue is that this kind of defeats the purpose of the encapsulation.
I've tried spreading the width of the components and setting different styles/classes to the input boxes etc. After a few hours, I realize that I'm at a loss.
Is it possible to make the injected tag app-textbox spread fully in its parent?
I had the same issue. Here is the way I solved it.
Original app.component.html:
<div class="container-fluid">
<div class="row">
<app-one></app-one>
<app-two></app-two>
</div>
</div>
Original one.component.html:
<div class="col-9">
<p>One</p>
</div>
Original two.component.html:
<div class="col-3">
<p>Two</p>
</div>
I moved 'col' divs from one and two components to the app component:
New app.component.html:
<div class="container-fluid">
<div class="row">
<div class="col-9">
<app-one></app-one>
</div>
<div class="col-3">
<app-two></app-two>
</div>
</div>
</div>
New one.component.html:
<p>One</p>
New two.component.html:
<p>Two</p>
For css to be visible in all your components, add it directly to the index.html file, or to app.component.css.
For example on the index.html as the last head element include:
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap#3.3.7/dist/css/bootstrap.min.css"
integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
</head>
That URL was taken from : https://getbootstrap.com/docs/3.3/getting-started/
(I'm assuming that your Angular2 project was generated with angular-cli and the files follow the standard names)
About the extra margin, try checking app.component.html. Maybe there's a container div around it. Also check index.html itself
I would like to know if, according to BEM methodology, I can have the following structure:
.block1
.block1__element1
.block2
.block1__element2 <-- ??
Am I allowed to use an element from a parent block, inside a children block?
Thanks.
UPDATE:
This is the actual DOM structure:
<div class="head">
<div class="head__user"></div>
<div class="head__nav">
<div class="menu">
// <-- ???
</div>
</div>
</div>
According to best practices of BEM methodology: am I allowed to move the element with head__user inside the menu block? Or all elements inside the menu block need to start with the menu__ prefix?
I hope this clears out the problem.
I been using BEM for sometime and from what I got it's not recommended nor intended to be used like that. You can nest different BEM elements to each other like menu-blockintohead-block, but menu-block items should not go outside its parent menu-block, like you should not put menu-block__item at the top of head-block. Does it makes sense? :)
To illustrate there are two ways to go. What should be noted here is that depending on the scale of your project and how you build things (component based?). If you don't have a large project and are not doing or reusing the menu else where you can do it both ways. Lets say your menu is huge amount of html/css I would do it like #1
This is not correct
<div class="head">
<div class="head__user"></div>
<div class="head__nav">
<div class="menu">
<div class="head__something"></div>
</div>
</div>
</div>
Recommended solution
Based on this part of the documentation. Now you can chop your own header design into blocks, does this below match?
<div class="head">
<div class="head__user"></div>
<div class="head__nav">
<div class="menu">
<div class="menu__something"><img src="" class="menu__image" /></div>
</div>
</div>
</div>
I think this variant is allowed:
<div class="head">
<div class="head__nav">
<div class="menu">
<div class="head__user"></div>
</div>
</div>
</div>
I haven't found the current part in the official BEM documentation, but I've found this part:
The block name defines the namespace, which guarantees that the elements are dependent on the block (block__elem).
A block can have a nested structure of elements in the DOM tree:
Example
<div class="block">
<div class="block__elem1">
<div class="block__elem2">
<div class="block__elem3"></div>
</div>
</div>
</div>
However, this block structure is always represented as a flat list of elements in the BEM methodology:
Example
.block {}
.block__elem1 {}
.block__elem2 {}
.block__elem3 {}
This allows you to change a block's DOM structure without making changes in the code for each separate element:
Example
<div class="block">
<div class="block__elem1">
<div class="block__elem2"></div>
</div>
<div class="block__elem3"></div>
</div>
The block's structure changes, but the rules for the elements and their names remain the same.
I understand it as there is only one rule about HTML structure for elements in BEM: an element has to be inside its block (it doesn't matter how deep).
One possible problem that I can imagine for this case is using some of BEM tree formats. But if you don't need it, I think there's no problem.
I would consider making the potential head__something into simply something, and then to provide multiple modifications of it. e.g. something--head and something--menu.
<div class="head">
<div class="head__user"></div>
<div class="head__nav">
<div class="menu">
<div class="something--menu" />
</div>
</div>
<div class="something--head" />
</div>
Also, refactoring further, I would consider getting rid of head__nav as it probably does not add any richer semantics than menu.
<div class="head">
<div class="head__user"></div>
<div class="menu">
<div class="something--menu" />
</div>
<div class="something--head">for those cases where you want <code>something</code> directly descending from <code>head</code></div>
</div>
Let's say I have a product within a collection. Is it appropriate to call the product "feature-collection__product" so it's still an element within the block of "feature-collection" or call it "feature-collection-product" so it becomes it's own block, as it has other elements within it, or something different.
<div class="feature-collection">
<div class="feature-collection__product">
<h2 class="feature-collection__product-title"></h2>
<h2 class="feature-collection__product-price"></h2>
</div>
</div>
OR
<div class="feature-collection">
<div class="feature-collection-product">
<h2 class="feature-collection-product__title"></h2>
<h2 class="feature-collection-product__price"></h2>
</div>
</div>
Most likely the correct answer is both:
<div class="feature-collection">
<div class="feature-collection__product product">
<h2 class="product__title"></h2>
<h2 class="product__price"></h2>
</div>
</div>
The situation when you have different entities on the same DOM node is called mix. In this case it's reasonable to have independent block product and also an element of feature-collection to set some styling for production inside feature-collection.
For more info about mixes please take a look at https://en.bem.info/methodology/key-concepts/#mix and https://en.bem.info/methodology/faq/#mixes
it seems to be simple , our designer made the a design of 3 different forms in one like page
as you may see in this snippet
I don't think we can do this design with valid html in twitter bootstrap grids ?
where you would get the form opening and closing tags and keep it valid
<div class="container">
<div class="col-md-4">
<div class="row"><div class="form1">form1</div></div>
<div class="row"><div class="form2">form2</div></div>
<div class="row"><div class="form3">form3 </div></div>
</div>
<div class="col-md-4">
<div class="row"><div class="form3">continue of form3 </div></div>
</div>
<div class="col-md-4">
<div class="row">
<div class="form3">
continue of form3
</div>
</div>
</div>
</div><!-- /.container -->
You cannot split a form element so that one part is inside one element and another part is inside another element. HTML syntax prevents that.
You can, however, have input elements and other controls outside a form element and associate them functionally with it using form attributes. Browser support is still too limited to make this a feasible option in normal situations.
Please review the Fiddle Here...
I am trying to separate some elements here and I'm having a tough time. All my div tags appear correctly separated, but I'm not getting the separation.
For example, I've got a button, then a clear, then a paragraph.
But, the paragraph is actually showing up inside the button, after the clear.
<div id="container">
<div id="header">Transfer of Credit Estimator</div>
<div id="content">
<div id="classes">Enter total number of classes estimated for transfer, then click <strong>Estimate</strong>.
</div>
<input type="text" class="" placeholder="#">
<div id="btn">Estimate<div> <!-- Button -->
</div>
<div class="clear"></div>
<p>Hi</p>
<div id="footer">**The Estimator is based on classes that would transfer in as 4-credit courses that cost $1,608 each ($402/credit hour) here at University. The Estimator assumes that each class would be a 5-week class.</div> <!-- Footer -->
</div> <!-- Close Container -->
</div>
On top of that, the footer is taking on attributes from the '.btn' class, such as the font-family and font-weight.
Thoughts on what I'm doing wrong here?
The button div is not closed. It should be:
<div class="btn">Estimate</div>
The button div is not closed
<div id="btn">Estimate<div>
instead it should be
<div id="btn">Estimate</div>
Your browser tries to correct you missing closing tag and that creates the attributes to shift