Transcript JavaScript
JavaScript William Hosbein L1k3 th3 c00l l00k1ng d3s1gn? JavaScript: Early Days • 1995. Netscape Navigator incorporated Java into its browser. • Enter Brendan Eich. Netscape hired Eich and gave him the task to make Navigator’s Java support more accessible to nonJava programmers/developers. • Eich decided that a loosely-typed scripting language would suit the audience and environment. • His target audience was a few thousand web designers and developers who needed to use page elements, such as forms, frames, or images, without a compiler or knowledge of OOP. wHY n07 7RY 4 H0l1D4y 1N 1R3l4nD 7H1z y34R? JavaScript: Early Problems • Initially called “LiveScript,” JavaScript was soon renamed in an apparent marketing mistake. This caused much confusion for developers because both names were being tossed around in the development community. • By intention, JavaScript was very simple. This did create a problem though. • The fact that there was no compiler and that copying & pasting code from/to web pages was very easy caused many to view JavaScript as a toy. • JavaScript also lacked an IDE and a reliable cross-platform debugger. This, combined with a few security flaws and several books aimed at non-programmers, caused many to view it as “simple,” completely overshadowing its potential. 533 t3h 9r33n k0un7ri51D3 JavaScript: Early Successes? • Amongst its problems, JavaScript did gain popularity. • Although not its main intention, the biggest use of JavaScript, early on, was controlling images and document contents. • Surprisingly, the main use of JavaScript was the switching of images in response to mouse events. • Navigator’s implementation of JavaScript – which allowed for this image swapping – was something that IE lacked. • Developers actually started to only check for Navigator in their scripts, ignoring IE as a lost cause. • Ignoring IE all together for developing created another bump in the road for a true cross-platform standards-driven Web. 7h3 w0nd3rful pu85 JavaScript: Moving On • Issues during the browser wars affected a standards-driven Web. Thus, compatibility problems with JavaScript were rampant from browser to browser. • It was decided that JavaScript be handed over to an international standards body called the ECMA to take the development away from competing browser developers. • JavaScript was even officially renamed to ECMAScript or ECMA-262, but it’s still widely referred to as JavaScript. 4nD m4ny 1n73R3571n' M491C4L cr347ur3z JavaScript: Now • JavaScript’s dependence on context-specific object models is both the strength and weakness in its implementation. • Unlike other languages, JavaScript’s capabilities can’t be extended or overridden by developers. This leaves them dependent on the unpredictable software vendors. • Despite these drawbacks, JavaScript is the most popular and widely used language on the net. l1K3 73H L177L3 l3Pr3Ch4un5 JavaScript: Cons • Inability to hide source • Example: Obstacle for developers who wish to protect their code as intellectual property. • Lack of an IDE, debugger, and other development tools • Example: Some WYSISYG development tools with excellent crossbrowser libraries have been hurt by Mozilla’s abandonment of the old Netscape document.layers object model. 4 l3pr3Ch4uN 0nC3 4774Ck3D My s1ST3R... JavaScript: Pros • Features from Perl: • associative arrays • loosely typed variables • regular expressions • Features from C/C++ and Java: • clean, block-parsed syntax, objects and classes • highly evolved date, math, and string libraries N0 r3411Y! 5h3 W42 PICkIN9 cL0V3R2 wi7H 4 5p4d3 9iV3N H3r 8Y 7yl3R - H3r 80yFri3nD - 4 pud9Y ph00784Ll3R 4ND 5in9Er 0F M4Ny 50N95: "73h 83LLy 0f a Ph0078alL3r", "73H 5h032 0f P0W3R", "H0W 70 rUN ph457"... The End!!! Well, of the history part, you’re not rid of me yet