DisplayObject to base64 is it possible?

Solar2D General Questions/Discussion
#1

Hi, im using media.selectPhoto() for a user to upload photos to a rest api using base64.

I create a temporay file pass that file to string(binary>string), encode to base64 in the process then send it to the server. the problem is media.selectPhoto() send to the listner when i select the photo too soon. what i mean is the photo is still not created  when media.selectPhoto jumps to the listner. i create a delay to correct this so this work with a delay. i don’t like this method, since the time of creating the image i can’t control and the delay, could fail.

My question is, if i remove this all steps of creating tempory files, i could pass direct object to binary>string>base64. is it possible?

if not, shouldn’t the listner on media.selectPhoto when a file is chosed in destiny, get called only after the file is created? i hate using timers.

regards,

Carlos.

#2

noone knows if i can pass a display object direct to a string?

#3

I’m not sure I follow what you mean by pass a display object to a string. That’s what base64 encoding does. You pass binary data in and you get a string object out. Binary can’t be represented as a string because it’s binary. The purpose of base64 encoding is to make something that can be used as a string from the binary data.

Rob

#4

Rob, thx for your reply. i will try to explain better.

i made an object with display.newImageRect.

that object is in memory only, not in a file.

i want to pass that object to a base64 string so i can pass it though a rest api.

what i usually do, i need to pass that object to a file, then open it in binary then pass to base64 then close file then delete file. i was wondering if there is a easyway to do this passing directly an display.object>base64.

regards,

Carlos.

#5

If you’re loading an image into a display.newImageRect(), then just use the file IO API’s to read the file in, not as a display object but a blob of data, base64 encode that blob. 

If you’re making a new image rect using various techniques, you would need to save that display object out as a file using display.save() and then read it back in with the file IO API’s and the base64 encode the blob.

Rob

#6

the problem is exactly that. how to open an display.newImageRect() using IO API. remember i’m creating the image from media.selectPhoto(). i don’t have access to the original file.

i can’t just 

local fileHandle = io.open( filename, “rb” ). file name is an display.newImageRect() object.

your second option is already what i’m using. i’m hoping there are a better way than this, if corona can save an object to a binary file i should pass that same object to a base64string.

i need a a way that works like io.open but for objects in memory.

Carlos.

#7

If it’s not a physical file you have access to, you will need to use one of the screen saving functions like display.save() to turn a display object into a physical file. Then you can open it and base64 encode it.

Rob

#8

noone knows if i can pass a display object direct to a string?

#9

I’m not sure I follow what you mean by pass a display object to a string. That’s what base64 encoding does. You pass binary data in and you get a string object out. Binary can’t be represented as a string because it’s binary. The purpose of base64 encoding is to make something that can be used as a string from the binary data.

Rob

#10

Rob, thx for your reply. i will try to explain better.

i made an object with display.newImageRect.

that object is in memory only, not in a file.

i want to pass that object to a base64 string so i can pass it though a rest api.

what i usually do, i need to pass that object to a file, then open it in binary then pass to base64 then close file then delete file. i was wondering if there is a easyway to do this passing directly an display.object>base64.

regards,

Carlos.

#11

If you’re loading an image into a display.newImageRect(), then just use the file IO API’s to read the file in, not as a display object but a blob of data, base64 encode that blob. 

If you’re making a new image rect using various techniques, you would need to save that display object out as a file using display.save() and then read it back in with the file IO API’s and the base64 encode the blob.

Rob

#12

the problem is exactly that. how to open an display.newImageRect() using IO API. remember i’m creating the image from media.selectPhoto(). i don’t have access to the original file.

i can’t just 

local fileHandle = io.open( filename, “rb” ). file name is an display.newImageRect() object.

your second option is already what i’m using. i’m hoping there are a better way than this, if corona can save an object to a binary file i should pass that same object to a base64string.

i need a a way that works like io.open but for objects in memory.

Carlos.

#13

If it’s not a physical file you have access to, you will need to use one of the screen saving functions like display.save() to turn a display object into a physical file. Then you can open it and base64 encode it.

Rob