here is an example in jsfiddle.
I want to know if I can append a javascript object to innerHTML, that get that object again from innerHTML as object.
something like,
alert((this.innerHTML).html);
that's just an example, don't ask me why do you need this?
I'm trying to edit an existing code, and I have to do this so.
I have to transfer an object via div.innerHTML.
Check this jsfiddle. In it, I add the object to the div as a 'data-'-attribute, using JSON to convert it to a string. After that, adding some comment to the div triggers the DOMSubtreeModified-handler, in which the 'html'-part of the object is retrieved and alerted. It that something to work with?
In this case, quite possible your only option is to convert your object to string and then put that into the element. (This is done by looping through the key, values building the string as you go.)
You would reverse the process to convert it back into an obj.
I know some javascript libary's have helper functions to make this process very simple.
You could try adding the data directly onto the dom element, rather than as its content..
tempDiv.objData = myObject;
It was suggested to use JSON, but no code. So:
function addObjAsJSON(el, obj) {
el.setAttribute('data-myJSON', encodeURIComponent(JSON.stringify(obj)));
}
function getObjAsJSON(el) {
return JSON.parse(decodeURIComponent(el.getAttribute('data-myJSON')));
}
That should allow you to add anything as a serialised object, then get it back. You should add some error checking to make it robust though (e.g. check that you get a string back from the call to getAttribute).
For user agents that don't have built-in JSON support, see json.org which has a link in the javascript section to json.js.
Related
At the moment I am storing a few objects in Firebase. After successfully retrieving the items from Firebase and storing them in a firebaseArray, I want to further thin out the unwanted elements by deleting the elements in the firebaseArray that do not have the desired property. Consider my code at the moment, that does not do as wanted, however there are no errors in the console:
var querylatestPosts = firebase.database().ref("Topics");
$scope.latestPosts = $firebaseArray(querylatestPosts);
console.log($scope.latestPosts) ;
$scope.latestPosts.forEach(function(el) {
if ($scope.checkWorldview(el) == false) {
delete $scope.latestPosts.el ;
}
});
(Note I am unable to log 'el' in the console, nor does the forEach seem to execute, as I can log nothing in the function in the console)
The 'checkWorldview' function behaves as expected when elements are fed in different instances and returns false if the required property is not present in the element under consideration. Thus if the function returns false, I want to delete the specific element in $scope.latestPosts that does not contain the wanted property.
I hope this is clear, thank you in advance for any help you can offer!
The way you are using the $firebaseArray isn't recommended by the docs (see here), which state that $firebaseArray is read only and should not be manipulated.
So you have a few options:
Instead of filtering the array on the client-side, you should modify the query you're using to retrieve data from Firebase to only get elements that have the desired property (ex: use 'equalTo' in the query)
OR
Don't use a $firebaseArray because you're not using it in the way it was intended. Use a regular, good ol' fashion JavaScript array instead.
** Also, just a general comment: don't delete elements from an array as you loop through it as this is generally bad practice (we don't expect arrays to have elements added/removed while we loop through them). Instead, use Array.filter.
I want to edit JavaScript in a textarea and store it back into a JavaScript object. For example I have this object:
var item1 = {
'id' : 1,
'title':'title',
'sourcecode' : "alert('hallo')"
};
If I would change the content to alert("hallo") or a even more complex example does this break my object?
I would think there is some escape function like this https://developer.mozilla.org/de/docs/Web/JavaScript/Reference/Global_Objects/escape. But it is marked as deprecated.
So if this is deprecated what would be the right way for storing complex JavaScript code into a JavaScript object?
Should I use stringify ?
https://developer.mozilla.org/de/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify
The JSON.stringify() method converts a JavaScript value to a JSON
string, optionally replacing values if a replacer function is
specified, or optionally including only the specified properties if a
replacer array is specified.
This does not read like there is an automated escape build in.
If you need to send the data to a server, I'd say you should encodeURI your sourceCode, and then JSON.stringify the entire object. When retreiving data from the server, you should decodeURI the sourceCode
I know there are a lot of questions on serializing objects in Javascript, but I'm trying to serialize a string to JSON objects after using the method .getData() from one of the APIs for later use. It returns a string, but I can't get any attributes.
Here is an example of what I did. I need to serialize this to a JSON object, but it just returns me this type of object. Is there a way that I can get the source of this audio element after serializing it with JSON.stringtify() ?
http://imgur.com/K4RhCht
You can use JSON.parse(theSerializedElement), set it as the innerHTML of an HTML element that you can dynamically create and then use DOM methods to get the attribute.
If I am understanding you correctly you want to serialize DOM element's attributes or some of them, or may be data attached to it. You will need to iterate through them on your own.
So you have some HTML as a string, and you want to get the value of an attribute in the audio tag?
EDIT: Assuming your string is in the data variable.
If you're using jQuery:
var source = jQuery(data).attr('src');
Without jQuery, it's still fairly straightforward.
var container = document.createElement('div');
container.innerHTML = data;
var source = container.querySelector('audio').getAttribute('src');
If one has the output of a JSON.parse readily at hand, is there some legitimate way of storing that object in the DOM as a single entity?
i.e.
jsonObject = JSON.parse(something);
I'd like to consider storing the jsonObject in the DOM as a (child || textNode || ???) of some element and later retrieving it so that immediately after retrieval I could access its contents via the usual:
jsonObject.keyName
I want to avoid adding dozens of dataset attributes and later being forced to extract them one at a time. That's too much work and seems too inefficient if you have dozens of key:value pairs.
Data attributes have to be strings, you can't store objects in them directly. So don't parse the JSON string, just store the JSON string directly in the dataset attribute.
If you use jQuery, its .data() method will take an object, and it will automatically stringify it as needed.
If the elements you want to associate the object with all have IDs, another option is to use a global object as a table, keyed off the element's ID.
jsonTable[id] = jsonObject;
It depends on the life cycle of your page. If you don't intend to reload the page it's better to just leave it as a JavaScript variable on the page.
You can also consider storing the raw JSON in a hidden filed or some other hidden DOM element. Keep in mind though that hidden fields will be posted to the server if you do a post of the page
TGH has the right answer. Leave it as a variable.
An alternative is to use history.pushState() to store it along with the URL to your page. This is helpful if you ever want the user to be able to click the back button and have the json restored to the value it had for that page.
If you want to store a data (JSON) associated with DOM element.
You could use jQuery data function.
e.g., store a JSON to a restaurant row (div)
$("div.restaurant-row").data("info",{purchases: "blablabla", mealFormulas: "xxxxx"});
e.g., fetch DOM associatd data
$("div.restaurant-row").data("info").purchases; //blablabla
I'm not sure if this is what you want.
Hope this is helpful for you.
I'm doing a fairly exhaustive series of DOM manipulations where a few elements (specifically form elements) have some events.
I am dynamically creating (actually cloning from a source element) several <select> boxes and assigning a change() event to them.
The change event executes, and within the context of the event, "this" is the HTML Element Object.
What I need to do at this point however is determine a context for this HTML Element Object. I have these objects stored already as jQuery entities in assorted arrays, but obviously
[HTMLElement Object] != [Object Object]
And the trick is that I cannot cast $(this) and make a valid comparison since that would create a new object and the pointer would be different.
So... I've been banging my head against this for a while. In the past I've been able to circumvent this problem by doing an innerHTML comparison, but in this case the objects I am comparing are 100% identical, just there's lots of them. Therefore I need a solid comparison.
This would be easy if I could somehow derive the HTMLElement object from my originating jQuery object.
Thoughts, other ideas? Help. :(
This would be easy if I could somehow derive the HTMLElement object from my originating jQuery object
you don't just mean $("#object")[0] or $("#object").get(0) with 'derive' do you?
Can't you just use $(this).data("something") to keep data on your elements and then check the values later? (That's assuming you can't just give these things plain ol' "id" values.)
Oh also jQuery itself has a "guid" element that you can use (be careful!)
$(myNewObject).data("identity", $.quid++);
If you maintain a jQuery object containing the elements you've created/cloned (let's call it "jqClonedElements"), you can reduce that set to the single element matching "this" with $().filter(element):
var jqThis = jqClonedElements.filter(this);
After this, you may want to confirm that your element was found, as follows:
var elementWasFound = (jqThis.length > 0);
That should be all there is to it!
-Matt