apache - java velocity vm file #set use boolean variable -


we can not use boolean variable #set when find velocity project guidelines in apache official site,but worked when use in project.

#set($isright=true) #if($isright) ##execute #end  #set($isright=false) #if($isright) ##not execute #end

i want know whether #set boolean variable supported velocity , way use whether legal.

in velocity, there no explicit data types , hence there no boolean variables support. since velocity has been built on java platform, if specify compatible value can give expected results in such operations "if" operation (the 1 shown in code). because in java, boolean value expected in if expression , providing can casted boolean.

if give #set($isright=true1) , above written code internally treated java engine specified string inside 'if' expression couldn't casted boolean , hence throw type cast exception(or classcastexception). happen value other 'true' or 'false' strings here can casted boolean expected inside 'if' expression.

thus not boolean type support, java implementation behind scenes makes things work.


Comments

Post a Comment

Popular posts from this blog

searchKeyword not working in AngularJS filter -

i writing app using angularjs on front end. want search through table word/field; 1 search box everything. according article here: http://hello-angularjs.appspot.com/searchtable can use filter: searchkeyword this. this code, , not working expected. <label>search: <input ng-model="searchkeyword"></label> <table ng-repeat="post in posts | orderby: sort | filter: searchkeyword"> <tr> <td> {{index(post)}} </td> <td> {{post.title}} </td> <td> {{post.author}} </td> <td> {{post.content}} </td> <td> {{post.date | date: "d/m/yyyy"}} </td> </tr> </table> what should do? thank you try this: controller $scope.posts = [ {title:'title one', author:'author one', content: 'content one'}, {title:'title two', author:'author two', content: 'cont...
Read more

sequelize.js - Sequelize: sort by enum cases -

i have model ( article ) field (the name type ) of type enum('source', 'translated') , return 1 article ordered type field. source articles should returned before translated articles. like: article.findone(order: [ { type: [ 'source', 'translated' ] } ]); unfortunately there appears no built-in solution sorting enums. instead have sort by case , couldn't find documentation on how sequelize. what conventional approach here? sorting case hard in sequelize, sort field (the second answer in linked post) should possible: order: sequelize.fn('field', sequelize.col('type'), 'source', 'translated') it's supported mysql far know though
Read more

user interface - how to replace an ongoing process of image capture from another process call over the same ImageLabel in python's GUI TKinter -

i trying use following code create interactive gui changes color-space(hsv, rbg, grayscale etc) on event of button click. display opencv video in tkinter using multiprocessing being new python having problems multiprocessing , attempts on making gui change it's color space on button clicks hangs entire system. on it's implementation highly appreciated. thankyou. below code: import cv2 pil import image,imagetk import tkinter tk import numpy np multiprocessing import process , queue def quit_it(root,process): root.destroy() process.terminate() def black_andwhite(root,process): process.terminate p=process(target=capture_image, args=(5,queue, )) p.start() root.after(0, func=lambda: update_all(root, image_label, queue)) def update_image(image_label, queue): frame = queue.get() = image.fromarray(frame) b = imagetk.photoimage(image=a) image_label.configure(image=b) image_label._image_cache = b root.update() def update_all(root...
Read more